Adaptation of an immersive virtual reality serious game prototype for upper limb function training in post-stroke individuals: innovations and clinical applications

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Adapting existing serious games may represent a viable approach to tailoring interventions to the motor demands of specific populations. Accordingly, this study described the adaptation and redesign process of an immersive virtual reality game, Virtual Mente , originally developed for cognitive training in older adults, for upper-limb reaching training in post-stroke individuals. Methods This descriptive study outlined the functional adaptation and redesign process of the Virtual Mente serious game for a new target population. The methodological process was divided into three main stages: (1) description and analysis of the therapeutic potential of the original game version; (2) implementation of initial adjustments and adaptations based on internal testing and iterative discussions between researchers and developers; and (3) final testing and technical refinement of the adapted version. Results Following meetings between developers and researchers conducted from November 2023 to October 2025, three primary adaptation axes were identified: (1) biomechanical and kinematic adjustments of movements related to task execution; (2) application of motor learning principles to enable upper-limb reaching training in post-stroke individuals; and (3) implementation of strategies to ensure user sensory comfort during immersive virtual reality exposure. These adaptations resulted in the redesign of game interactions, including the creation of a new phase with additional targets and objects, increased movement variability, and audiovisual modifications to improve interaction and sensory tolerability. Conclusions The adaptation process enabled the redesign of Virtual Mente into a prototype with characteristics more consistent with the therapeutic demands of upper-limb reaching training after stroke. By integrating clinical, biomechanical, and motor learning principles, the adapted version may represent a promising complementary tool for rehabilitation training in immersive virtual reality. Future steps include content validation by experts and usability testing with post-stroke individuals. Virtual Reality Upper Extremity Serious Games Rehabilitation Stroke Figures Figure 1 Figure 2 Figure 3 Figure 4 Background Virtual reality (VR) has emerged as a promising strategy in neurorehabilitation, particularly when combined with conventional therapy to support the recovery upper-limb function in post-stroke individuals [ 1 – 5 ]. In rehabilitation settings, VR interventions are frequently delivered through digital games that create interactive environments capable of stimulating engagement and task practice during therapy [ 4 ]. These games can be broadly classified as serious games, which are developed for educational, training, or therapeutic purposes, or commercial games designed primarily for entertainment and immersive experiences [ 6 – 10 ]. Within therapeutic contexts, serious games have been increasingly explored as tools to support rehabilitation processes by integrating specific training objectives into structured game environments [ 8 – 11 ]. Despite advances in new game development of new VR-based games, the absence of standardized approaches for game design, therapeutic parameters, and outcome interpretation has limited the consistent application of these technologies in clinical practice [ 13 – 16 ]. In this context, adapting existing games represents a viable and sustainable strategy, allowing previously tested technological resources to be repurposed and tailored to the specific motor demands of rehabilitation. This approach can reduce development costs while facilitating the incorporation of therapeutic principles into games originally designed for other purposes, thereby expanding their clinical applicability [ 8 , 11 , 12 , 16 ]. When appropriately adapted, serious games can incorporate kinematic and motor parameters commonly used in clinical practice, enabling alignment with game tasks and therapeutic goals according to the individual’s stage of recovery [ 14 – 15 ]. Such integration may support different levels of motor recovery, guide the selection of more appropriate interventions, and enhance the precision of therapeutic objectives during training [ 15 , 16 ]. Furthermore, understanding how these technical parameters contribute to the design and refinement of VR games may support the development of more effective interventions that promote clinically meaningful improvements in motor function while maintaining patient engagement throughout training [ 17 , 18 ]. These considerations highlight the growing need not only for the development but also for the adaptation of existing serious games to address specific rehabilitation demands, such as upper-limb training in post-stroke individuals. Although this process involves technical and developmental challenges, adapting previously established digital environments may provide more accessible and targeted therapeutic tools [ 19 – 21 ]. Within this context, this study aims to describe the adaptation process of an immersive virtual reality (IVR) game, Virtual Mente , originally developed for cognitive training in older adults, for upper-limb reaching training in post-stroke individuals. Methods This descriptive study aimed to describe the functional adaptation and redesign process of the serious game Virtual Mente for upper-limb reaching training in post-stroke individuals. The project was conducted through a partnership between the Strategic Health Technologies Center (NUTES) at the State University of Paraíba (UEPB) and the Virtual Reality Intervention and Research Laboratory (LIPERV) at the Federal University of Rio Grande do Norte (UFRN), between November 2023 and October 2025. Game testing activities were carried out internally by members of LIPERV/UFRN, while programming, implementation of modifications, and system updates were managed by the NUTES/UEPB development team. The methodological process was organized into three main stages: (1) description and analysis of the therapeutic potential of the original game version, conducted between November 2023 and April 2024; (2) initial adjustments and adaptations of the game, carried out from August to December 2024; and (3) final testing and technical refinement of the adapted game version. The most recent version, completed in October 2025, is currently undergoing testing for content validation and usability assessment by specialists in computer science and rehabilitation. At the end of each methodological stage, multidisciplinary meetings were held to produce testing reports, ensuring integration of technical, clinical, and user-experience perspectives throughout the adaptation process for the new target population. The study was approved by the Research Ethics Committee of the UFRN (CAAE: 85298124.6.0000.5537; Approval No. 7,682,556). Additionally, the use and storage of user data from the original version of the game for cognitive training in older adults, managed by NUTES, was approved by the Research Ethics Committee of the UEPB (CAAE: 81694124.0.0000.5187; Approval No. 7,020,886). Results Serious game Virtual Mente Virtual environment and gameplay The Virtual Mente prototype was originally developed to address cognitive aspects in older adults through a simulation of a virtual home environment designed to provide a familiar and pleasant experience, thereby promoting immersion and user engagement. The game takes place at a dining table, where the user remains seated centrally and interact with objects positioned on the table surface. Four plates are arranged horizontally in front of the user, while fruits and vegetables are randomly placed on a tray located to the left. The main task consists of use one hand to grasp the fruits and vegetables from the tray and place them onto the corresponding plates, one object at a time. The session is ends once all objects have been correctly placed on their respective targets. To indicate the correct sequence of object placement, a floating panel is displayed above the table in front of the user. The order in which objects must be placed on the targets is randomized at the beginning of each new phase. The system provides visual and auditory feedback for each action. Correct placements are indicated by a green halo surrounding the target accompanied by a characteristic sound, whereas incorrect placements trigger a red halo and a different sound cue. The system also allows visualization of a virtual hand that simulates grasping and manipulation movements within the virtual environment. After completing a phase, a congratulatory panel appears, followed by a transition to a panel showing the message “waiting for the next phase” (Fig. 1). The originally version of Virtual Mente was developed by NUTES/UEPB in partnership with the Study and Research Group in Neurosciences, Exercise, Health, and Sports at the State University of Montes Claros. Figure 1. Initial version of the Virtual Mente game. (a) Visual feedback indicating correct and incorrect responses during task execution. (b) Virtual kitchen environment used to simulate functional reaching tasks. (c) Representation of the virtual hand during task execution. (d) Congratulatory panel displayed upon phase completion. Source: Authors’ data (Strategic Health Technologies Center, State University of Paraíba [NUTES/UEPB]; Study and Research Group in Neurosciences, Exercise, Health, and Sports, State University of Montes Claros). Device and connectivity The game requires a head-mounted display system, specifically the Meta Quest 2 or Quest 3 device, which enables full immersion in a virtual environment. This system tracks the user’s hand position and gestures in real-time using built-in sensors, eliminating the need for handheld controllers to capture hand movements. At the end of each phase, the generated data are collected and transmitted to an application programming interface, where they are organized and subsequently displayed on a web-based platform by NUTES. In this system, a phase corresponds to a single task cycle within the game, whereas a session refers to the complete gameplay period that may include multiple phases during a training session. Access to this platform requires prior registration and an individual password for each therapist, ensuring user data security and facilitating the use of the platform’s available resources (Fig. 2 ). The web-based platform was designed as a support tool for therapists, allowing them to manage device connectivity, initiate game phases, register new users, access previously records user data, and monitor individual performance indicators. These indicators include the number of correct and incorrect responses, time spent in each phase, movement dominance, and reaching velocity (Fig. 3 ). During gameplay, the therapist can observe the user’s perspective through an external display using Meta’s built-in projection feature. Based on this projection, the therapist may guide the user during task execution or provide additional feedback when necessary to complete the phase. This configuration allows the user to focus exclusively on the tasks proposed by the game, while the therapist manages the technical and clinical aspects through the platform, ensuring a smoother and more efficient experience for both. Analysis of the game’s therapeutic potential The originally version of the game was primarily designed for cognitive training in older adults and included tasks involving visual recognition of fruits and vegetables, these tasks required users to identify objects and place them on the corresponding targets according to a predefined sequence, thereby stimulating selective processes such as selective attention, short-term memory, and visual working memory. In addition to these cognitive demands, the game also required basic motor planning to execute the sequence of reaching and object placement actions within the virtual environment. Although the originally version demonstrated potential for cognitive training, its applicability for motor rehabilitation was limited. The interaction tasks involved restricted upper-limb joint movements and promoted low biomechanical variability, providing limited opportunities for structured reaching practice. The interaction tasks involved restricted upper-limb joint movements and promoted low biomechanical variability, providing limited opportunities for structured reaching practice. As a result, essential elements commonly required in motor rehabilitation, such as repeated reaching movements and progressive increases in task difficulty, were not sufficiently incorporated into the game design. Based on the limitations identified during testing of the original prototype, a series of meetings were conducted between the development team at NUTES/UEPB and researchers from LIPERV/UFRN to define the adaptation strategy for the game. During these meetings, the collaborative workflow, distribution of responsibilities between the laboratories, development timeline, testing stages, and procedures for documenting and analyzing the modifications implemented in the game were established. Definition of the game enhancement axes During the initial internal analyses conducted by the LIPERV research team, the original version of the game was examined through exploratory internal testing performed by laboratory members. As part of the laboratory’s routine development activities, researchers and students scheduled individual testing sessions to interact freely with the virtual environment and explore the game tasks and system functionalities. During these sessions, participants evaluated aspects related to task execution, interaction demands, usability, and potential limitations for motor training. Following these testing sessions, observations and suggestions were discussed collectively during laboratory meetings, resulting in a summary document that compiled the main strengths, limitations, and technical issues identified during testing. This evaluation indicated that the game presented a solid design framework and coherent task structure, which facilitated its potential adaptation for motor training purposes and the integration of game-generated performance data with selected clinical assessment parameters. The primary objective of this stage was to identify components of the game that required modification to ensure its suitability for the new target population. In addition to evaluating the game’s structural characteristics, this phase also involved identifying and correcting software flaws or implementation defects, commonly referred to as bugs, that could compromise system functionality. Such bugs may negatively affect user experience by interfering with usability, reducing performance stability, or compromising the accuracy of data stored on the web-based platform. Following this initial analysis, meetings between the NUTES and LIPERV teams, conducted between November 2023 and April 2024, enabled the identification of key elements related to both training demands and user comfort. Based on these discussions, three primary enhancement axes were established to guide the adaptation process: (1) biomechanical and kinematic adjustment of movements associated with in-game task execution; (2) application of motor learning principles to support upper-limb training in post-stroke individuals; and (3) implementation of strategies to ensure user sensory comfort and adherence to IVR-based therapy. Discussion First game adaptation Identification of functional errors and virtual environment suitability To identify aspects of the game requiring adaptation for use by post-stroke individuals, internal testing was conducted by the LIPERV research team between November 2023 and April 2024. This exploratory phase allowed the researchers to examine the technical performance, interaction dynamics, and environmental characteristics of the original game version. The analysis indicated that the virtual environment presented a coherent structural organization and stable interaction framework, which are important prerequisites for the implementation of rehabilitation-oriented tasks. However, specific adjustments were required to ensure that the interaction demands of the game adequately supported upper-limb motor training in individuals with post-stroke impairments. These considerations are particularly relevant because post-stroke individuals frequently present with combined sensory, perceptual, and motor deficits that require carefully structured and stable virtual environments. Previous studies have demonstrated that virtual environments should minimize sensory overload by maintaining clear visual organization, controlled stimulus presentation, and environmental stability during task execution. These characteristics are essential to facilitate attention, movement planning, and safe task performance in users with neurological impairments [ 20 – 23 ]. Furthermore, accurate real-time tracking of user movements and stable device connectivity represent critical factors for ensuring safety and reliability during virtual environment–based interventions [ 22 , 23 ]. At the end of the testing phase, a structured report was prepared to document the main observations identified during internal evaluation, encompassing five main evaluation dimensions. The final report was developed based on the observations and suggestions reported during internal testing sessions. These observations were subsequently discussed in laboratory meetings, and the most frequently reported issues and adaptation needs were consolidated to guide the modification process. The five dimensions included: (1) platform and game connectivity; (2) virtual environment design; (3) game initiation, interactivity, and completion; (4) bug identification and correction; and (5) additional improvement suggestions (Table 1 ). These dimensions allowed the research team to systematically identify both technical issues and interaction aspects requiring modification, which subsequently informed the definition of the game enhancement axes, including biomechanical and kinematic adjustments of movement execution, the incorporation of motor learning principles for upper-limb rehabilitation, and strategies to promote sensory comfort and adherence during IVR-based therapy. Table 1 Evaluated dimensions and proposed improvements in the initial version of the Virtual Mente game. GAME ASPECTS OBSERVATIONS Platform and game connectivity • Instabilities in synchronization between the device and the platform, affecting bidirectional communication Virtual environment design • Excessive brightness and high sound volume at the beginning of the phase Game initiation, interactivity, and completion • Fruits and vegetables positioned too close to each other on the tray. • Congratulatory panel and “waiting for the next phase” message panel with dimensions disproportionate to the virtual environment. • Virtual hand displaying a standardized grasping movement, regardless of the manipulated item. • High sound volume at phase initiation and during item interaction. • Presence of black lines on some fruits. Bug identification and correction • Duplication of the virtual hand when grasping items on the tray. Additional improvement suggestions • Inclusion of a chair as a reference for user positioning. • Development of an informational panel displaying phase duration, number of errors, and correct responses. • Addition of focused lighting over the table and reduction of background brightness. • Inclusion of a panel considering not only correct item placement but also the layout of the plates on the table. • Replacement of the external landscape visible through the window with a more realistic environment. • Development of a new phase with nine plates and the addition of new fruits and vegetables. Note: Data were derived from internal testing conducted by researchers from the LIPERV, focusing on functional adaptation for upper-limb reaching training in post-stroke individuals. The table summarizes identified issues and corresponding improvements related to technical, aesthetic, and interaction aspects of the game. Adaptation to movement biomechanics and kinematics To analyze the biomechanical and kinematic movement demands associated with task execution in the game, the potential ranges of joint of the upper-limb were initially identified, including movements at the shoulder, elbow, wrist, and fingers. These movements comprised flexion, extension, abduction, adduction, internal and external rotation, pronation, supination, and radial and ulnar deviation [ 25 ]. Mapping these possible joint actions allowed the research team to determine which motor components were required to perform each game phase and how they contributed to task completion. The analysis of movement organization was conducted according to the continuous movement framework, which considers the sequential organization of motor behavior during task execution. Within this model, movement is analyzed across different stages, including the initial condition, preparation, initiation, execution, and termination of the task. The initial condition refers to both the environmental context and the individual’s posture before movement onset, whereas preparation involves non-observable processes related to movement planning and motor programming. The observable components include initiation, corresponding to the moment when body segments begin to move; execution, defined as the period during which effective segment displacement occurs; and termination, marking the completion of the movement [ 25 – 29 ]. Biomechanical and kinematic evaluations of upper-limb movements were conducted through direct observation and audiovisual recordings obtained during gameplay. For this purpose, LIPERV researchers interacted with the game while movements were recorded from multiple angles. This procedure allowed a detailed examination of how each virtual task element influenced the organization of movement in the real environment. The recordings were subsequently reviewed to identify motor patterns, segmental movement phases (initiation, execution, and termination), and the specific demands imposed by interactions with virtual objects. Video analysis indicated that, during the reaching phase, movements were predominantly characterized by shoulder flexion and abduction combined with elbow extension, enabling hand transport toward the target. During the prehension preparation phase, fine adjustments in hand positioning were observed, involving forearm pronation or supination and subtle wrist flexion and extension movements. At the moment of grasping, finger flexion and wrist stabilization occurred, requiring coordinated activation of intrinsic and extrinsic hand muscles. During item manipulation, precise and coordinated finger movements were required, accompanied by postural adjustments of the shoulder and elbow to maintain grip stability and proximal control (Table 2 ). Table 2 Joint movements and motor demands identified in the Virtual Mente game tasks. Core Task Phase Shoulder Elbow Wrist Fingers REACHING TASK Initiation Flexion; Abduction; External rotation Extension Flexion; Extension; Pronation; Supination Flexion; Extension Execution Flexion; Abduction; External rotation Extension Flexion; Extension; Pronation; Supination Flexion; Extension Termination Flexion; Abduction; External rotation Extension Flexion; Extension; Pronation; Supination Flexion; Extension GRASPING TASK Initiation Flexion; Abduction; Adduction; Internal rotation; External rotation Flexion; Extension Flexion; Extension; Pronation; Supination; Ulnar deviation; Radial deviation Flexion; Extension; Abduction; Adduction; Thumb opposition Execution Flexion; Abduction; Adduction; Internal rotation; External rotation Flexion; Extension Flexion; Extension; Pronation; Supination; Ulnar deviation; Radial deviation Flexion; Extension; Abduction; Adduction; Thumb opposition Termination Flexion; Abduction; Adduction; Internal rotation; External rotation Flexion; Extension Flexion; Extension; Pronation; Supination; Ulnar deviation; Radial deviation Flexion; Extension; Abduction; Adduction; Thumb opposition MANIPULATION TASK Initiation Flexion; Extension; Abduction; Adduction; Internal rotation; External rotation Flexion; Extension Flexion; Extension; Pronation; Supination; Ulnar deviation; Radial deviation Flexion; Extension; Abduction; Adduction; Thumb opposition Execution Flexion; Extension; Abduction; Adduction; Internal rotation; External rotation Flexion; Extension Flexion; Extension; Pronation; Supination; Ulnar deviation; Radial deviation Flexion; Extension; Abduction; Adduction; Thumb opposition Termination Flexion; Extension; Abduction; Adduction; Internal rotation; External rotation Flexion; Extension Flexion; Extension; Pronation; Supination; Ulnar deviation; Radial deviation Flexion; Extension; Abduction; Adduction; Thumb opposition Note: Shoulder, elbow, wrist, and finger movements required for reaching, grasping, and manipulation tasks were analyzed across task phases (initiation, execution, and termination), based on the model proposed by Hedman [28]. This analysis also revealed limitations of the original game for motor training purposes. Although the original version incorporated reaching, grasping, and manipulation actions, the tasks did not provide sufficient biomechanical challenges for post-stroke individuals. The activities exhibited limited variability in range of motion, lacked spatial variation of targets, imposed low demands on trunk and upper-limb dissociation, required minimal pronation and supination movements, and relied on relatively simple interaction tasks with limited potential to promote neural adaptation. These findings highlighted the need for structural modifications to ensure that the game could generate motor stimuli aligned with the therapeutic goals of upper-limb rehabilitation. Application of motor learning principles After identifying the motor demands with task execution in the game, motor learning principles were considered to guide the adaptation of the system for upper-limb reaching training in post-stroke individuals. The literature describes four primary mechanisms that contribute to motor learning: use-dependent learning, instruction-based learning, reinforcement learning, and sensorimotor adaptation. In the game context, use-dependent learning is promoted through the repeated execution of reaching, grasping, and manipulation actions involving virtual objects. Instruction-based learning is conveyed through visual and auditory cues, as well as performance-related feedback provided to the user during interaction with the virtual environment. Reinforcement learning occurs through success and error signals and progression between phases that inform users about their performance. Finally, sensorimotor adaptation is triggered when users must adjust their movements in response to changes in the virtual environment, such as item location, response timing, or interaction dynamics [ 30 , 31 ]. The logic of the original game version already incorporated some fundamental motor learning mechanisms, such as task-oriented practice combined with immediate visual and auditory feedback. These elements allow users to monitor their performance and adjust movements during task execution, supporting the formation of stable motor memories and facilitating neural plasticity processes essential for motor recovery after stroke [ 30 , 32 , 33 ]. However, functional analysis of the original version revealed important limitations, particularly the need to increase the number of targets and introduce randomization in object presentation to strengthen key elements associated with neural reorganization in post-stroke individuals. Increasing the number of targets was considered essential to enhance motor exploration. New targets were therefore added at different spatial locations on the table, enabling multitarget reaching and stimulating movements across multiple directions, ranges of motion, and joint combinations. This modification enriched the diversity of trained motor patterns and expanded the functional motor repertoire required for post-stroke recovery. In addition, randomization of object presentation disrupted predictable movement sequences, increased cognitive-motor demands, and strengthened sensorimotor adaptation processes, thereby contributing to cortical reorganization and improved generalization of motor learning [ 34 , 35 ]. Based on these considerations, the developers implemented a new game phase. The original version was maintained as Phase 1, while Phase 2 incorporated additional motor demands. Although the virtual environment remained unchanged, five additional plates were introduced, resulting in a total of nine targets distributed according to the model adapted from Stewart’s study [ 36 ]. The increased number of targets promoted greater movement variability by encouraging reaching across multiple directions, ranges of motion, and joint combinations. Additionally, 14 different types of fruits and vegetables were introduced and randomly distributed across two trays positioned at the left and right corners of the table, facilitating bilateral training and enabling task execution with either upper limb. This adaptation aimed to increase the complexity of the reaching task by establishing a graded progression of difficulty. Targets located closer to the user require smaller joint excursions and lower motor effort compared with more distant targets. Similarly, targets positioned on the ipsilateral side of the affected limb allow gradual increases in reaching difficulty. To further introduce practice variability, a randomization model was applied to object placement on the targets, ensuring that the arrangement changes at the beginning of each phase and thereby increasing task complexity and variability (Fig. 4 ). Strategies to ensure user sensory comfort Audiovisual adaptations of the VR environment were also implemented to enhance user comfort and reduce the risk of sensory discomfort during gameplay. Factors influencing sensory discomfort during VR exposure are commonly grouped into three main categories: content-related factors, hardware-related factors, and user-related characteristics. Content-related factors include the design of visual elements as well as camera movement, speed, and direction within the virtual environment. Hardware-related factors involve characteristics such as display type, field of view, interaction range, and frame rate. Finally, user-related factors include individual characteristics such as sex, age, prior VR experience, susceptibility to motion sickness, and duration of exposure to the virtual experience [ 36 – 39 ]. Sensory discomfort associated with VR exposure, commonly referred to as cybersickness, is characterized by symptoms such as sweating, yawning, dizziness, spatial disorientation, fatigue, nausea, and vomiting during or after exposure to virtual environments [ 36 , 40 , 41 ]. Among the theoretical explanations for these symptoms, sensory conflict theory proposes that cybersickness arises from a mismatch between incoming sensory information and prior bodily experiences [ 42 – 44 ]. In contrast, multisensory reweighting theory suggests that these symptoms may result from discrepancies between expected and perceived sensory stimuli, indicating that susceptibility to cybersickness may depend on an individual’s capacity to rapidly resolve conflicting multisensory signals generated during VR interaction [ 45 ]. Based on these considerations, several adaptations were implemented in the game to improve sensory comfort (Table 1 ). These modifications included adjustments to lighting, sound, and visual design, such as adding focused lighting over the table, reducing background scene brightness, balancing sound effects, and using lower-contrast colors schemes. These modifications are particularly relevant for post-stroke individuals, who often exhibit increased sensitivity to brightness and contrast, slowed sensory integration, susceptibility to spatial disorientation, and increased visual or cognitive fatigue. By reducing peripheral stimuli, stabilizing the virtual environment, and minimizing sensory overload, these adaptations improve tolerability for users with lower sensory thresholds, decrease the risk of cybersickness, and enhance the safety, comfort, and clinical feasibility of using the game in rehabilitation [ 7 , 46 , 47 ]. Second game adaptation Final testing and technical improvements of the game’s final version After receiving the new version of Virtual Mente , which incorporated the proposed adaptations, redesign, and creation of Phase 2, additional internal testing was conducted by members of the LIPERV research team following the same exploratory procedures adopted in the previous testing stage. During this stage, new demands related to Phase 2 were identified, particularly regarding object design, correction of additional bugs, interaction challenges, platform connectivity, and synchronization between real-world movements and their virtual representations. Observations from this phase informed final adjustments to optimize the user experience, improve fidelity between real and virtual motor execution, and prepare the prototype for expert validation. Key outcomes encompassed various aspects of the game and web platform. For the platform and connectivity, improvements included the addition of filters to locate or exclude users on the web platform, as well as enhancements in device connectivity and synchronization. Concerning the game environment design, corrections were requested for the textures and shapes of fruits and vegetables, adjustments to plate design, and modifications to the light–dark contrast within the game environment. Regarding game initiation, interactivity, and completion, adjustments included object manipulation, adaptations of virtual hand visualization according to grasp type (pinch and palmar), improvements in the logic for object placement on the plates, and a reduction in waiting time between the end of one phase and the start of the next. For bug correction, issues were identified in object interactions during manipulation, errors in counting hits and mistakes within the game, and inconsistencies in the virtual environment when generating or resuming the same phase. Finally, additional recommendations included replacing the chair design with a standard dining chair model, creating an informational panel for the user to display data on phase duration, number of errors, successes, and final percentage, and modifying object presentation on the targets using translucent images positioned above each plate. The new improvement demands for Phase 2 targeted key aspects of the clinical applicability of VR games for post-stroke rehabilitation. Accordingly, the adjustment of the synchronization and tracking of user movements in the real environment and their corresponding representation in the virtual environment can minimize perceptual–motor discrepancies, ensuring that accurate feedback is provided for each action, which is essential for promoting motor learning processes [ 21 ]. Similarly, modifications to contrast, lighting, and visual stability of the scenario can reduce perceptual fatigue and prevent the sensory overload commonly experienced by post-stroke individuals [ 45 , 47 , 48 ]. By controlling these aspects, the virtual environment becomes more tolerable, safe, and functionally oriented toward motor performance, reducing sensory input that can impair motor planning. These adjustments make the game more responsive to the user’s motor and sensory needs, allowing therapists to conduct training in a more structured and safe manner, thereby increasing the clinical applicability of VR-based rehabilitation [ 47 , 48 ]. The latest version of the game prototype was delivered to LIPERV in October 2025 and is currently undergoing testing for content validation and usability assessment by professionals with expertise in computer science and rehabilitation. These procedures correspond to the subsequent phases of the study and aim to evaluate the clarity, relevance, and usability of the system before its application with end users. Theoretical perspectives and evidence on the development and use of serious games in rehabilitation This study describes the functional adaptation and redesign of the Virtual Mente game, originally developed for cognitive training in older adults and subsequently reconfigured for functional upper-limb training in post-stroke individuals. While retaining the original virtual environment, the game was expanded to include a new phase with additional plates, fruits, vegetables, and trays, thereby increasing interaction opportunities and motor demands. These modifications were implemented collaboratively between developers and researchers through an iterative process guided by clinical and biomechanical principles, resulting in a tool better aligned with the requirements of motor and functional training in individuals with upper-limb impairments. Current frameworks for the development of serious games in rehabilitation emphasize two main axes: the standardization of the design process based on clinical requirements and patient-centered principles, along with the incorporation of motivational elements to enhance therapeutic adherence [ 10 – 13 ]. Redesigning IVR serious games for rehabilitation requires integrating kinetic-functional and biomechanical demands into game tasks. In parallel, strategies for sensory comfort within virtual environments must be incorporated to reduce cybersickness symptoms and ensure a clinically oriented and tolerable user experience. Following a framework similar to that proposed by Ambros-Antemate [ 10 ], the adaptation of Virtual Mente adopted an iterative and collaborative workflow between physiotherapists and programmers, ensuring alignment between clinical objectives and game design and reinforcing the practical applicability of conceptual models in the creation and development of IVR serious games. One of the theoretical approaches frequently used to understand engagement and motivation in digital rehabilitation games is the Self-Determination Theory [ 50 ]. This theory proposes that motivated behavior is sustained by the fulfillment of three basic psychological needs: autonomy, competence, and relatedness. Autonomy refers to the perception of control over one’s actions, competence emerges from successfully performing appropriately challenging tasks, and relatedness reflects the sense of connection with a meaningful context. In the redesign of Virtual Mente , these principles were considered to support engagement during training. Direct interaction with game elements encourages a sense of autonomy, progressive increases in task difficulty support the perception of competence, and immersion in a familiar and coherent virtual environment may facilitate the user’s sense of connection with the task context. In addition to theoretical aspects related to motivation and engagement, the identification and correction of bugs played an important role in the adaptation process of the game for post-stroke individuals. In IVR systems, the integration between hardware and software requires high levels of stability and synchronization to ensure that user actions are accurately represented in the virtual environment [ 49 , 51 ]. Addressing technical inconsistencies during the development process therefore contributes to improving interaction reliability and supports the iterative cycles commonly involved in the design and refinement of serious games for rehabilitation. Similarly, considering the joint demands involved in reaching and object manipulation tasks allowed the redesign of game interactions to incorporate movements requiring different ranges of motion and joint combinations. This approach may provide clinicians with observable motor patterns during task execution that could support qualitative observations of motor control during rehabilitation training [ 28 , 29 , 52 ]. The gamification strategies incorporated into serious games aim to promote and sustain engagement during repetitive motor training tasks. One mechanism frequently discussed in the literature is the promotion of a state of flow, characterized by deep involvement in the activity when task difficulty is balanced with the user’s abilities [ 13 ]. and immediate visual feedback can act as reinforcing signals for correct movement execution. In Virtual Mente , the use of visual feedback and gradual adjustments in the spatial distribution and distance of reaching targets sought to maintain an appropriate balance between challenge and ability. his approach may help prevent common responses associated with repetitive training, such as boredom when tasks are overly simple or frustration when they are excessively difficult, thereby supporting motivation and engagement during practice and potentially facilitating motor learning processes and neuroplasticity [ 21 , 28 , 53 ]. A limitation of this study is that, to date, the validation process has been conducted only internally. Although this approach allowed close alignment with the perspectives of the development and research teams, the absence of usability testing with post-stroke individuals and formal validation by field experts remains an important limitation. The subsequent phases of the study will involve content validation by specialists and usability testing with the target population. These stages aim to evaluate system clarity, usability, and acceptance, as well as to explore its potential effects on upper-limb motor performance in post-stroke individuals. Conclusions This study described the functional adaptation and redesign of the IVR game Virtual Mente , integrating clinical, biomechanical, and motor learning principles into its redesign to better address the therapeutic demands of upper-limb reaching in post-stroke individuals. The implemented modifications improved aspects related to movement precision, variability of reaching tasks, and sensory conditions within the virtual environment, highlighting the potential applicability of the prototype as a complementary tool for rehabilitation training. Future steps include content validation by experts, usability testing with post-stroke individuals, and the integration of kinematic and clinical measures to further investigate its potential effectiveness and applicability in therapeutic contexts. Abbreviations LIPERV Virtual Reality Intervention and Research Laboratory NUTES Strategic Health Technologies Center VR Virtual Reality IVR Immersive Virtual Reality UEPB State University of Paraíba UFRN Federal University of Rio Grande do Norte Declarations Ethics approval and consent to participate The study related to the redesign and adaptation of the serious game Virtual Mente for post-stroke individuals was approved by the Research Ethics Committee (CEP) of Federal University of Rio Grande do Norte (UFRN; CAAE: 85298124.6.0000.5537, Opinion No. 7,682,556), and the use and storage of user data from the original version of the game for cognitive training in older adults by Strategic Health Technologies Center (NUTES) was approved by the CEP of State University of Paraíba (UEPB; CAAE: 81694124.0.0000.5187, Opinion No. 7,020,886). Consent for publication Not applicable. Availability of data and materials No datasets were generated or analyzed during the current study. Competing interests The authors declare no competing interests. Funding This study was financed in part by the Coordination for the Improvement of Higher Education Personnel (CAPES), Brazil, Finance Code 001. Authors’ contributions LCAC and VLC conceived the study, contributed to the design of the adaptation process, and drafted the manuscript. PESB contributed to the development of the virtual reality system and implementation of game modifications. DJSS and LBAF participated in the methodological design and analysis of the therapeutic framework. LBAF and VLC contributed to data interpretation and critical revision of the manuscript. FACC supervised the study and critically revised the manuscript. All authors read and approved the final manuscript. Acknowledgements The authors thank the Postgraduate Program in Physical Therapy at the Federal University of Rio Grande do Norte, Natal, Brazil, for supporting this study. We also thank the Coordination for the Improvement of Higher Education Personnel, Brazil (CAPES), for financial assistance (Finance Code 001). Author information ¹ PhD student in Physiotherapy, Federal University of Rio Grande do Norte (UFRN), Brazil. ² PhD student in Physiotherapy, Federal University of Rio Grande do Norte (UFRN), Brazil. ³ Master’s student in Physiotherapy, Federal University of Rio Grande do Norte (UFRN), Brazil. ⁴ Resident in Public Health, School of Public Health of Ceará (ESP/CE), Brazil. ⁵ PhD professor, State University of Paraíba (UEPB), Brazil. ⁶ PhD professor, Federal University of Rio Grande do Norte (UFRN), Brazil. References Ali AS, Arumugam A, Gururaj S, Sardesai S, Kumaran DS. Effects of game-based rehabilitation on upper limb motor function following acute and sub-acute stroke: a systematic review, meta-analyses, and GRADE evidence synthesis. Virtual Real. 2025;29:79. Laver KE, Lange B, George S, Deutsch JE, Saposnik G, Chapman M, et al. Virtual reality for stroke rehabilitation. Cochrane Database Syst Rev. 2025;2025:CD008349. Zhang J, Liu M, Yue J, Yang J, Xiao Y, Yang J, et al. Effects of virtual reality with different modalities on upper limb recovery: a systematic review and network meta-analysis on optimizing stroke rehabilitation. Front Neurol. 2025;16:1544135. Soleimani M, Ghazisaeedi M, Heydari S. The efficacy of virtual reality for upper limb rehabilitation in stroke patients: a systematic review and meta-analysis. BMC Med Inf Decis Mak. 2024;24:135. Kiper P, Przysiezna E, Cieslik B, Broniec-Siekaniec K, Kucinska A, Szczygiel J, et al. Effects of immersive virtual therapy as a method supporting recovery of depressive symptoms in post-stroke rehabilitation: randomized controlled trial. Clin Interv Aging. 2022;17:1673–85. Alvarez J, Djaouti D. An introduction to serious game definitions and concepts. In: Proceedings of the Serious Games & Simulation Workshop. 2011. Doumas I, Everard G, Dehem S, Lejeune T. Serious games for upper limb rehabilitation after stroke: a meta-analysis. J Neuroeng Rehabil. 2021;18:100. Fregna G, Paoluzzi C, Baroni A, Cano-de-la-Cuerda R, Casile A, Straudi S. Head-mounted displays for upper limb stroke rehabilitation: a scoping review. J Clin Med. 2023;12:7444. Baluz R, Teles A, Fontenele JE, Moreira R, Fialho R, Azevedo P, et al. Motor rehabilitation of upper limbs using a gesture-based serious game: evaluation of usability and user experience. Games Health J. 2022;11:177–85. Ambros-Antemate JF, Beristain-Colorado MP, Vargas-Treviño M, Gutiérrez-Gutiérrez J, Hernández-Cruz PA, Gallegos-Velasco IB, et al. Improving adherence to physical therapy in the development of serious games: conceptual framework design study. JMIR Form Res. 2023;7:e39838. Beristain-Colorado MP, Ambros-Antemate JF, Vargas-Treviño M, Gutiérrez-Gutiérrez J, Moreno-Rodriguez A, Hernández-Cruz PA, et al. Standardizing the development of serious games for physical rehabilitation: conceptual framework proposal. JMIR Serious Games. 2021;9:e25854. Xiao Y, Bai H, Gao Y, Hu B, Zheng J, Cai X, et al. Interactive virtual ankle movement controlled by wrist sEMG improves motor imagery: an exploratory study. IEEE Trans Vis Comput Graph. 2024;30:5507–24. van Gaalen AEJ, Brouwer J, Schönrock-Adema J, Bouwkamp-Timmer T, Jaarsma ADC, Georgiadis JR. Gamification of health professions education: a systematic review. Adv Health Sci Educ Theory Pract. 2021;26:683–711. Levin MF, Hiengkaew V, Nilanont Y, Cheung D, Dai D, Shaw J, et al. Relationship between clinical measures of upper limb movement quality and activity poststroke. Neurorehabil Neural Repair. 2019;33:432–41. Villepinte C, Verma A, Dimeglio C, De Boissezon X, Gasq D. Responsiveness of kinematic and clinical measures of upper-limb motor function after stroke: a systematic review and meta-analysis. Ann Phys Rehabil Med. 2021;64:101366. Diriba Kenea C, Gemechu Abessa T, Lamba D, Bonnechère B. Technological features of immersive virtual reality systems for upper limb stroke rehabilitation: a systematic review. Sens (Basel). 2024;24:3546. Melo G, Junior JRZ, Lopes JB, Duarte NAC, Oliveira DAP, Rezende LP, et al. Effects of treadmill and virtual reality gait training on the quality of life of people with Parkinson’s disease. Gait Posture. 2024;113:201–2. Minelli C, Bazan R, Pedatella MTA, Neves LO, Cacho RO, Magalhães SCSA, et al. Brazilian Academy of Neurology practice guidelines for stroke rehabilitation: part I. Arq Neuropsiquiatr. 2022;80:634–52. Sánchez-Gil JJ, Sáez-Manzano A, López-Luque R, Ochoa-Sepúlveda JJ, Cañete-Carmona E. Gamified devices for stroke rehabilitation: a systematic review. Comput Methods Programs Biomed. 2025;258:108476. Herrera V, Albusac J, Castro-Schez JJ, González-Morcillo C, Monekosso DN, Pacheco S, et al. Creating adapted environments: enhancing accessibility in virtual reality for upper limb rehabilitation through automated element adjustment. Virtual Real. 2025;29:28. Jiao Y, Fermin P, Qi D, Stacey Z, Smith RM, Zhang Y. A clinically oriented VR-based treadmill training system for post-stroke rehabilitation: integration of motor learning and control principles. Virtual Real. 2025;29:112. Chander H, Arachchige SNKK, Hill CM, Turner AJ, Deb S, Shojaei A, et al. Virtual-reality-induced visual perturbations impact postural control system behavior. Behav Sci (Basel). 2019;9:113. Wilson EB, Bergquist JS, Wright WG, Jacobs DA. Gait stability in virtual reality: effects of VR display modality in the presence of visual perturbations. J Neuroeng Rehabil. 2025;22:32. Lippert LS. Clinical kinesiology and anatomy. Philadelphia: Lippincott Williams & Wilkins; 2013. Sahrmann SA. The human movement system: our professional identity. Phys Ther. 2014;94:1034–42. Sahrmann S, Azevedo DC, Van Dillen L. Diagnosis and treatment of movement system impairment syndromes. Braz J Phys Ther. 2017;21:391–9. Hedman LD, Quinn L, Gill-Body K, Brown DA, Quiben M, Riley N, et al. White paper: movement system diagnoses in neurologic physical therapy. J Neurol Phys Ther. 2018;42:110–7. Quinn L, Riley N, Tyrell CM, Judd DL, Gill-Body KM, Hedman LD, et al. A framework for movement analysis of tasks: recommendations from the Academy of Neurologic Physical Therapy’s Movement System Task Force. Phys Ther. 2021;101:pzab154. Zarzycki R, Malloy P, Eckenrode BJ, Fagan J, Malloy M, Mangione KK. Application of the 4-element movement system model to sports physical therapy practice and education. Int J Sports Phys Ther. 2022;17:18–26. Leech KA, Roemmich RT, Gordon J, Reisman DS, Cherry-Allen KM. Updates in motor learning: implications for physical therapist practice and education. Phys Ther. 2022;102:pzab250. McCluskey A, Lannin NA, Schurr K, Dorsch S, Christie LJ. Skills and strategies for improving arm function and occupational participation after acquired brain impairment. In: Curtin M, Egan M, Parnell T, Prior Y, Sauvé-Schenk D K, et al. editors. Occupational therapy for people experiencing illness, injury or impairment. 8th ed. Edinburgh: Elsevier; 2024. Cezar da Cruz. Drews R, Pacheco MM, Bastos FH, Tani G. Knowledge of results does not affect self-efficacy and skill acquisition on an anticipatory timing task. J Mot Behav. 2021;53:275–86. Matsugi A, Yoshida N, Nakano H, Okada Y. The neurorehabilitation of neurological movement disorders requires rigorous and sustained research. J Clin Med. 2024;13:852. Hanlon RE. Motor learning following unilateral stroke. Arch Phys Med Rehabil. 1996;77:811–5. Maier M, Ballester BR, Verschure PFMJ. Principles of neurorehabilitation after stroke based on motor learning and brain plasticity mechanisms. Front Syst Neurosci. 2019;13:74. Stewart JC, Lewthwaite R, Rocktashel J, Winstein CJ. Self-efficacy and reach performance in individuals with mild motor impairment due to stroke. Neurorehabil Neural Repair. 2019;33:319–28. Kim YS, Won JH, Jang SW, Ko J. Effects of cybersickness caused by head-mounted display-based virtual reality on physiological responses: cross-sectional study. JMIR Serious Games. 2022;10:e37938. Lim I, Cha B, Cho DR, Park E, Lee KS, Kim M. Safety and potential usability of immersive virtual reality for brain rehabilitation: a pilot study. Games Health J. 2023;12:34–41. Oh HJ, Lee GC. Feasibility of full immersive virtual reality video game on balance and cybersickness of healthy adolescents. Neurosci Lett. 2021;760:136063. Park WD, Jang SW, Kim YH, Kim GA, Son W, Kim YS. A study on cyber sickness reduction by oculo-motor exercise performed immediately prior to viewing virtual reality content on head mounted display. Vibroeng Procedia. 2017;14:260–4. Gallagher M, Ferrè ER. Cybersickness: a multisensory integration perspective. Multisens Res. 2018;31:645–74. Yang Y, Sun X, Zhang Y, Zhang H, Sun X, Yang C, et al. Effects of social interaction on virtual reality cybersickness. Displays. 2023;80:102512. Nam S, Jang KM, Kwon M, Lim HK, Jeong J. Electroencephalogram microstates and functional connectivity of cybersickness. Front Hum Neurosci. 2022;16:857768. Han X, Ke J, Jiang S, Zhang D. Gaming-based virtual reality therapy for the rehabilitation of upper extremity function after stroke. Chin J Phys Med Rehabil. 2016;12:401–5. da Silva Marinho A, Terton U, Jones CM. Cybersickness and postural stability of first-time VR users playing VR videogames. Appl Ergon. 2022;101:103698. Tosto-Mancuso J, Tabacof L, Herrera JE, Breyman E, Dewil S, Cortes M, et al. Gamified neurorehabilitation strategies for post-stroke motor recovery: challenges and advantages. Curr Neurol Neurosci Rep. 2022;22:183–95. Vieira C, Pais-Vieira CFS, Novais J, Perrotta A. Serious game design and clinical improvement in physical rehabilitation: systematic review. JMIR Serious Games. 2021;9:e20066. Diriba Kenea C, Gemechu Abessa T, Lamba D, Bonnechère B. AdaptRehab VR: development of an immersive virtual reality system for upper limb stroke rehabilitation designed for low- and middle-income countries using a participatory co-creation approach. Bioeng (Basel). 2025;12:581. Munoz-Novoa M, Andersson C, Sunnerhagen KS, Alt Murphy M. A novel intervention for upper limb rehabilitation in people with stroke combining myoelectric pattern recognition, virtual reality, and serious gaming: a qualitative study. Disabil Rehabil. 2025;47:3930–7. Uysal A, Yildirim IG. Self-determination theory in digital games. In: Bostan B, editor. Gamer psychology and behavior. Cham: Springer; 2016. AlMousa M, Al-Khalifa HS, AlSobayel H. Requirements elicitation and prototyping of a fully immersive virtual reality gaming system for upper limb stroke rehabilitation in Saudi Arabia. Mob Inf Syst. 2017;2017:1–12. Turolla A, Dam M, Ventura L, et al. Virtual reality for the rehabilitation of the upper limb motor function after stroke: a prospective controlled trial. J Neuroeng Rehabil. 2013;10:85. Muratori LM, Lamberg EM, Quinn L, Duff SV. Applying principles of motor learning and control to upper extremity rehabilitation. J Hand Ther. 2013;26:94–103. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 04 May, 2026 Reviewers agreed at journal 20 Apr, 2026 Reviewers invited by journal 16 Apr, 2026 Editor assigned by journal 18 Mar, 2026 Submission checks completed at journal 18 Mar, 2026 First submitted to journal 17 Mar, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9152421","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":626285351,"identity":"b26d4a29-087c-40fb-af83-6c9f83845c2c","order_by":0,"name":"Dayenne Jeneffer Souza Da Silva","email":"data:image/png;base64,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","orcid":"","institution":"Federal University of Rio Grande do Norte","correspondingAuthor":true,"prefix":"","firstName":"Dayenne","middleName":"Jeneffer Souza Da","lastName":"Silva","suffix":""},{"id":626285352,"identity":"a9cb6612-5a87-41b3-b969-8c1c35e0a6ae","order_by":1,"name":"Vitor Leandro Cunha","email":"","orcid":"","institution":"Federal University of Rio Grande do Norte","correspondingAuthor":false,"prefix":"","firstName":"Vitor","middleName":"Leandro","lastName":"Cunha","suffix":""},{"id":626285353,"identity":"0c7aa900-2395-4876-a431-4c930d0235db","order_by":2,"name":"Luanna Barbara Araújo Farias","email":"","orcid":"","institution":"Federal University of Rio Grande do Norte","correspondingAuthor":false,"prefix":"","firstName":"Luanna","middleName":"Barbara Araújo","lastName":"Farias","suffix":""},{"id":626285354,"identity":"40d7ee6d-8a97-4924-9fe3-7735246da5c1","order_by":3,"name":"Lara Cecília Araújo Carlos","email":"","orcid":"","institution":"Ceará School of Public Health","correspondingAuthor":false,"prefix":"","firstName":"Lara","middleName":"Cecília Araújo","lastName":"Carlos","suffix":""},{"id":626285355,"identity":"78914591-5f44-4319-a538-127788cdd3f0","order_by":4,"name":"Paulo Eduardo e Silva Barbosa³","email":"","orcid":"","institution":"State University of Paraíba","correspondingAuthor":false,"prefix":"","firstName":"Paulo","middleName":"Eduardo e Silva","lastName":"Barbosa³","suffix":""},{"id":626285356,"identity":"c26bab4d-f01e-435f-9121-61aaa621bb92","order_by":5,"name":"Fabricia Azevedo Cavalcanti¹","email":"","orcid":"","institution":"Federal University of Rio Grande do Norte","correspondingAuthor":false,"prefix":"","firstName":"Fabricia","middleName":"Azevedo","lastName":"Cavalcanti¹","suffix":""}],"badges":[],"createdAt":"2026-03-17 20:53:15","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9152421/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9152421/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107673768,"identity":"234cc964-1c0d-4236-ba55-85072d551ad0","added_by":"auto","created_at":"2026-04-23 23:24:20","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":3680411,"visible":true,"origin":"","legend":"\u003cp\u003eInitial version of the \u003cem\u003eVirtual Mente\u003c/em\u003e game. (a) Visual feedback indicating correct and incorrect responses during task execution. (b) Virtual kitchen environment used to simulate functional reaching tasks. (c) Representation of the virtual hand during task execution. (d) Congratulatory panel displayed upon phase completion. Source: Authors’ data (Strategic Health Technologies Center, State University of Paraíba [NUTES/UEPB]; Study and Research Group in Neurosciences, Exercise, Health, and Sports, State University of Montes Claros).\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-9152421/v1/707504c42996a554057c40b6.png"},{"id":107673772,"identity":"849b5a2f-065a-411e-8799-dcf874808c5b","added_by":"auto","created_at":"2026-04-23 23:24:23","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":281022,"visible":true,"origin":"","legend":"\u003cp\u003eSenior Saúde Móvel platform. Access interface of the web-based platform used to monitor and manage user participation in the intervention. Source: Authors’ data (NUTES/UEPB).\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-9152421/v1/7e8f2cca537627daf55abb04.png"},{"id":107673771,"identity":"93dc1b42-fa23-4278-8c62-c79073b88b56","added_by":"auto","created_at":"2026-04-23 23:24:20","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":480043,"visible":true,"origin":"","legend":"\u003cp\u003eSenior Saúde Móvel platform. Display of user performance data, including task-related metrics used to monitor progression and support clinical decision-making. Source: Authors’ data (NUTES/UEPB).\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-9152421/v1/b748e16ea41620c13cc4d50a.png"},{"id":107707611,"identity":"1d542c74-dae9-43a7-87e1-de28703acea1","added_by":"auto","created_at":"2026-04-24 09:20:45","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":2062225,"visible":true,"origin":"","legend":"\u003cp\u003eDifferences in the virtual environment between Phase 1 (a) and Phase 2 (b) of the IVR serious game \u003cem\u003eVirtual Mente\u003c/em\u003e, highlighting the increase in task complexity and interaction demands. Source: Authors’ data (NUTES/UEPB).\u003c/p\u003e","description":"","filename":"Figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-9152421/v1/31f06be4258e79a572e1e256.png"},{"id":107709263,"identity":"72771107-c057-4a16-be5d-18b2d63e83f7","added_by":"auto","created_at":"2026-04-24 09:35:13","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":6295178,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9152421/v1/c7c41eb7-52c7-4383-a33c-c9966ef57486.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Adaptation of an immersive virtual reality serious game prototype for upper limb function training in post-stroke individuals: innovations and clinical applications","fulltext":[{"header":"Background","content":"\u003cp\u003eVirtual reality (VR) has emerged as a promising strategy in neurorehabilitation, particularly when combined with conventional therapy to support the recovery upper-limb function in post-stroke individuals [\u003cspan additionalcitationids=\"CR2 CR3 CR4\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. In rehabilitation settings, VR interventions are frequently delivered through digital games that create interactive environments capable of stimulating engagement and task practice during therapy [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. These games can be broadly classified as serious games, which are developed for educational, training, or therapeutic purposes, or commercial games designed primarily for entertainment and immersive experiences [\u003cspan additionalcitationids=\"CR7 CR8 CR9\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Within therapeutic contexts, serious games have been increasingly explored as tools to support rehabilitation processes by integrating specific training objectives into structured game environments [\u003cspan additionalcitationids=\"CR9 CR10\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDespite advances in new game development of new VR-based games, the absence of standardized approaches for game design, therapeutic parameters, and outcome interpretation has limited the consistent application of these technologies in clinical practice [\u003cspan additionalcitationids=\"CR14 CR15\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. In this context, adapting existing games represents a viable and sustainable strategy, allowing previously tested technological resources to be repurposed and tailored to the specific motor demands of rehabilitation. This approach can reduce development costs while facilitating the incorporation of therapeutic principles into games originally designed for other purposes, thereby expanding their clinical applicability [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWhen appropriately adapted, serious games can incorporate kinematic and motor parameters commonly used in clinical practice, enabling alignment with game tasks and therapeutic goals according to the individual\u0026rsquo;s stage of recovery [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Such integration may support different levels of motor recovery, guide the selection of more appropriate interventions, and enhance the precision of therapeutic objectives during training [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Furthermore, understanding how these technical parameters contribute to the design and refinement of VR games may support the development of more effective interventions that promote clinically meaningful improvements in motor function while maintaining patient engagement throughout training [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThese considerations highlight the growing need not only for the development but also for the adaptation of existing serious games to address specific rehabilitation demands, such as upper-limb training in post-stroke individuals. Although this process involves technical and developmental challenges, adapting previously established digital environments may provide more accessible and targeted therapeutic tools [\u003cspan additionalcitationids=\"CR20\" citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Within this context, this study aims to describe the adaptation process of an immersive virtual reality (IVR) game, \u003cem\u003eVirtual Mente\u003c/em\u003e, originally developed for cognitive training in older adults, for upper-limb reaching training in post-stroke individuals.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eThis descriptive study aimed to describe the functional adaptation and redesign process of the serious game \u003cem\u003eVirtual Mente\u003c/em\u003e for upper-limb reaching training in post-stroke individuals. The project was conducted through a partnership between the Strategic Health Technologies Center (NUTES) at the State University of Para\u0026iacute;ba (UEPB) and the Virtual Reality Intervention and Research Laboratory (LIPERV) at the Federal University of Rio Grande do Norte (UFRN), between November 2023 and October 2025. Game testing activities were carried out internally by members of LIPERV/UFRN, while programming, implementation of modifications, and system updates were managed by the NUTES/UEPB development team.\u003c/p\u003e \u003cp\u003eThe methodological process was organized into three main stages: (1) description and analysis of the therapeutic potential of the original game version, conducted between November 2023 and April 2024; (2) initial adjustments and adaptations of the game, carried out from August to December 2024; and (3) final testing and technical refinement of the adapted game version. The most recent version, completed in October 2025, is currently undergoing testing for content validation and usability assessment by specialists in computer science and rehabilitation. At the end of each methodological stage, multidisciplinary meetings were held to produce testing reports, ensuring integration of technical, clinical, and user-experience perspectives throughout the adaptation process for the new target population.\u003c/p\u003e \u003cp\u003eThe study was approved by the Research Ethics Committee of the UFRN (CAAE: 85298124.6.0000.5537; Approval No. 7,682,556). Additionally, the use and storage of user data from the original version of the game for cognitive training in older adults, managed by NUTES, was approved by the Research Ethics Committee of the UEPB (CAAE: 81694124.0.0000.5187; Approval No. 7,020,886).\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e \u003cb\u003eSerious game\u003c/b\u003e \u003cb\u003eVirtual Mente\u003c/b\u003e\u003c/p\u003e\n\u003ch3\u003eVirtual environment and gameplay\u003c/h3\u003e\n\u003cp\u003eThe \u003cem\u003eVirtual Mente\u003c/em\u003e prototype was originally developed to address cognitive aspects in older adults through a simulation of a virtual home environment designed to provide a familiar and pleasant experience, thereby promoting immersion and user engagement. The game takes place at a dining table, where the user remains seated centrally and interact with objects positioned on the table surface. Four plates are arranged horizontally in front of the user, while fruits and vegetables are randomly placed on a tray located to the left. The main task consists of use one hand to grasp the fruits and vegetables from the tray and place them onto the corresponding plates, one object at a time. The session is ends once all objects have been correctly placed on their respective targets.\u003c/p\u003e \u003cp\u003eTo indicate the correct sequence of object placement, a floating panel is displayed above the table in front of the user. The order in which objects must be placed on the targets is randomized at the beginning of each new phase. The system provides visual and auditory feedback for each action. Correct placements are indicated by a green halo surrounding the target accompanied by a characteristic sound, whereas incorrect placements trigger a red halo and a different sound cue. The system also allows visualization of a virtual hand that simulates grasping and manipulation movements within the virtual environment. After completing a phase, a congratulatory panel appears, followed by a transition to a panel showing the message \u0026ldquo;waiting for the next phase\u0026rdquo; (Fig.\u0026nbsp;1). The originally version of \u003cem\u003eVirtual Mente\u003c/em\u003e was developed by NUTES/UEPB in partnership with the Study and Research Group in Neurosciences, Exercise, Health, and Sports at the State University of Montes Claros.\u003c/p\u003e \u003cp\u003e \u003cb\u003eFigure 1.\u003c/b\u003e Initial version of the \u003cem\u003eVirtual Mente\u003c/em\u003e game. (a) Visual feedback indicating correct and incorrect responses during task execution. (b) Virtual kitchen environment used to simulate functional reaching tasks. (c) Representation of the virtual hand during task execution. (d) Congratulatory panel displayed upon phase completion. Source: Authors\u0026rsquo; data (Strategic Health Technologies Center, State University of Para\u0026iacute;ba [NUTES/UEPB]; Study and Research Group in Neurosciences, Exercise, Health, and Sports, State University of Montes Claros).\u003c/p\u003e\n\u003ch3\u003eDevice and connectivity\u003c/h3\u003e\n\u003cp\u003eThe game requires a head-mounted display system, specifically the Meta Quest 2 or Quest 3 device, which enables full immersion in a virtual environment. This system tracks the user\u0026rsquo;s hand position and gestures in real-time using built-in sensors, eliminating the need for handheld controllers to capture hand movements. At the end of each phase, the generated data are collected and transmitted to an application programming interface, where they are organized and subsequently displayed on a web-based platform by NUTES. In this system, a phase corresponds to a single task cycle within the game, whereas a session refers to the complete gameplay period that may include multiple phases during a training session. Access to this platform requires prior registration and an individual password for each therapist, ensuring user data security and facilitating the use of the platform\u0026rsquo;s available resources (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe web-based platform was designed as a support tool for therapists, allowing them to manage device connectivity, initiate game phases, register new users, access previously records user data, and monitor individual performance indicators. These indicators include the number of correct and incorrect responses, time spent in each phase, movement dominance, and reaching velocity (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003e). During gameplay, the therapist can observe the user\u0026rsquo;s perspective through an external display using Meta\u0026rsquo;s built-in projection feature. Based on this projection, the therapist may guide the user during task execution or provide additional feedback when necessary to complete the phase. This configuration allows the user to focus exclusively on the tasks proposed by the game, while the therapist manages the technical and clinical aspects through the platform, ensuring a smoother and more efficient experience for both.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\n\u003ch3\u003eAnalysis of the game’s therapeutic potential\u003c/h3\u003e\n\u003cp\u003eThe originally version of the game was primarily designed for cognitive training in older adults and included tasks involving visual recognition of fruits and vegetables, these tasks required users to identify objects and place them on the corresponding targets according to a predefined sequence, thereby stimulating selective processes such as selective attention, short-term memory, and visual working memory. In addition to these cognitive demands, the game also required basic motor planning to execute the sequence of reaching and object placement actions within the virtual environment. Although the originally version demonstrated potential for cognitive training, its applicability for motor rehabilitation was limited.\u003c/p\u003e \u003cp\u003eThe interaction tasks involved restricted upper-limb joint movements and promoted low biomechanical variability, providing limited opportunities for structured reaching practice. The interaction tasks involved restricted upper-limb joint movements and promoted low biomechanical variability, providing limited opportunities for structured reaching practice. As a result, essential elements commonly required in motor rehabilitation, such as repeated reaching movements and progressive increases in task difficulty, were not sufficiently incorporated into the game design.\u003c/p\u003e \u003cp\u003eBased on the limitations identified during testing of the original prototype, a series of meetings were conducted between the development team at NUTES/UEPB and researchers from LIPERV/UFRN to define the adaptation strategy for the game. During these meetings, the collaborative workflow, distribution of responsibilities between the laboratories, development timeline, testing stages, and procedures for documenting and analyzing the modifications implemented in the game were established.\u003c/p\u003e\n\u003ch3\u003eDefinition of the game enhancement axes\u003c/h3\u003e\n\u003cp\u003eDuring the initial internal analyses conducted by the LIPERV research team, the original version of the game was examined through exploratory internal testing performed by laboratory members. As part of the laboratory\u0026rsquo;s routine development activities, researchers and students scheduled individual testing sessions to interact freely with the virtual environment and explore the game tasks and system functionalities. During these sessions, participants evaluated aspects related to task execution, interaction demands, usability, and potential limitations for motor training. Following these testing sessions, observations and suggestions were discussed collectively during laboratory meetings, resulting in a summary document that compiled the main strengths, limitations, and technical issues identified during testing.\u003c/p\u003e \u003cp\u003eThis evaluation indicated that the game presented a solid design framework and coherent task structure, which facilitated its potential adaptation for motor training purposes and the integration of game-generated performance data with selected clinical assessment parameters. The primary objective of this stage was to identify components of the game that required modification to ensure its suitability for the new target population. In addition to evaluating the game\u0026rsquo;s structural characteristics, this phase also involved identifying and correcting software flaws or implementation defects, commonly referred to as bugs, that could compromise system functionality. Such bugs may negatively affect user experience by interfering with usability, reducing performance stability, or compromising the accuracy of data stored on the web-based platform.\u003c/p\u003e \u003cp\u003eFollowing this initial analysis, meetings between the NUTES and LIPERV teams, conducted between November 2023 and April 2024, enabled the identification of key elements related to both training demands and user comfort. Based on these discussions, three primary enhancement axes were established to guide the adaptation process: (1) biomechanical and kinematic adjustment of movements associated with in-game task execution; (2) application of motor learning principles to support upper-limb training in post-stroke individuals; and (3) implementation of strategies to ensure user sensory comfort and adherence to IVR-based therapy.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eFirst game adaptation\u003c/h2\u003e \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e \u003ch2\u003eIdentification of functional errors and virtual environment suitability\u003c/h2\u003e \u003cp\u003eTo identify aspects of the game requiring adaptation for use by post-stroke individuals, internal testing was conducted by the LIPERV research team between November 2023 and April 2024. This exploratory phase allowed the researchers to examine the technical performance, interaction dynamics, and environmental characteristics of the original game version. The analysis indicated that the virtual environment presented a coherent structural organization and stable interaction framework, which are important prerequisites for the implementation of rehabilitation-oriented tasks. However, specific adjustments were required to ensure that the interaction demands of the game adequately supported upper-limb motor training in individuals with post-stroke impairments.\u003c/p\u003e \u003cp\u003eThese considerations are particularly relevant because post-stroke individuals frequently present with combined sensory, perceptual, and motor deficits that require carefully structured and stable virtual environments. Previous studies have demonstrated that virtual environments should minimize sensory overload by maintaining clear visual organization, controlled stimulus presentation, and environmental stability during task execution. These characteristics are essential to facilitate attention, movement planning, and safe task performance in users with neurological impairments [\u003cspan additionalcitationids=\"CR21 CR22\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Furthermore, accurate real-time tracking of user movements and stable device connectivity represent critical factors for ensuring safety and reliability during virtual environment\u0026ndash;based interventions [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAt the end of the testing phase, a structured report was prepared to document the main observations identified during internal evaluation, encompassing five main evaluation dimensions. The final report was developed based on the observations and suggestions reported during internal testing sessions. These observations were subsequently discussed in laboratory meetings, and the most frequently reported issues and adaptation needs were consolidated to guide the modification process.\u003c/p\u003e \u003cp\u003eThe five dimensions included: (1) platform and game connectivity; (2) virtual environment design; (3) game initiation, interactivity, and completion; (4) bug identification and correction; and (5) additional improvement suggestions (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). These dimensions allowed the research team to systematically identify both technical issues and interaction aspects requiring modification, which subsequently informed the definition of the game enhancement axes, including biomechanical and kinematic adjustments of movement execution, the incorporation of motor learning principles for upper-limb rehabilitation, and strategies to promote sensory comfort and adherence during IVR-based therapy.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eEvaluated dimensions and proposed improvements in the initial version of the \u003cem\u003eVirtual Mente\u003c/em\u003e game.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGAME ASPECTS\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOBSERVATIONS\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePlatform and game connectivity\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026bull; Instabilities in synchronization between the device and the platform, affecting bidirectional communication\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eVirtual environment design\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026bull; Excessive brightness and high sound volume at the beginning of the phase\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eGame initiation, interactivity, and completion\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026bull; Fruits and vegetables positioned too close to each other on the tray.\u003c/p\u003e \u003cp\u003e\u0026bull; Congratulatory panel and \u0026ldquo;waiting for the next phase\u0026rdquo; message panel with dimensions disproportionate to the virtual environment.\u003c/p\u003e \u003cp\u003e\u0026bull; Virtual hand displaying a standardized grasping movement, regardless of the manipulated item.\u003c/p\u003e \u003cp\u003e\u0026bull; High sound volume at phase initiation and during item interaction.\u003c/p\u003e \u003cp\u003e\u0026bull; Presence of black lines on some fruits.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBug identification and correction\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026bull; Duplication of the virtual hand when grasping items on the tray.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAdditional improvement suggestions\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026bull; Inclusion of a chair as a reference for user positioning.\u003c/p\u003e \u003cp\u003e\u0026bull; Development of an informational panel displaying phase duration, number of errors, and correct responses.\u003c/p\u003e \u003cp\u003e\u0026bull; Addition of focused lighting over the table and reduction of background brightness.\u003c/p\u003e \u003cp\u003e\u0026bull; Inclusion of a panel considering not only correct item placement but also the layout of the plates on the table.\u003c/p\u003e \u003cp\u003e\u0026bull; Replacement of the external landscape visible through the window with a more realistic environment.\u003c/p\u003e \u003cp\u003e\u0026bull; Development of a new phase with nine plates and the addition of new fruits and vegetables.\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cp\u003e\u003cstrong\u003eNote:\u003c/strong\u003e Data were derived from internal testing conducted by researchers from the LIPERV, focusing on functional adaptation for upper-limb reaching training in post-stroke individuals. The table summarizes identified issues and corresponding improvements related to technical, aesthetic, and interaction aspects of the game.\u003c/p\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eAdaptation to movement biomechanics and kinematics\u003c/h2\u003e \u003cp\u003eTo analyze the biomechanical and kinematic movement demands associated with task execution in the game, the potential ranges of joint of the upper-limb were initially identified, including movements at the shoulder, elbow, wrist, and fingers. These movements comprised flexion, extension, abduction, adduction, internal and external rotation, pronation, supination, and radial and ulnar deviation [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Mapping these possible joint actions allowed the research team to determine which motor components were required to perform each game phase and how they contributed to task completion.\u003c/p\u003e \u003cp\u003eThe analysis of movement organization was conducted according to the continuous movement framework, which considers the sequential organization of motor behavior during task execution. Within this model, movement is analyzed across different stages, including the initial condition, preparation, initiation, execution, and termination of the task. The initial condition refers to both the environmental context and the individual\u0026rsquo;s posture before movement onset, whereas preparation involves non-observable processes related to movement planning and motor programming. The observable components include initiation, corresponding to the moment when body segments begin to move; execution, defined as the period during which effective segment displacement occurs; and termination, marking the completion of the movement [\u003cspan additionalcitationids=\"CR26 CR27 CR28\" citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eBiomechanical and kinematic evaluations of upper-limb movements were conducted through direct observation and audiovisual recordings obtained during gameplay. For this purpose, LIPERV researchers interacted with the game while movements were recorded from multiple angles. This procedure allowed a detailed examination of how each virtual task element influenced the organization of movement in the real environment. The recordings were subsequently reviewed to identify motor patterns, segmental movement phases (initiation, execution, and termination), and the specific demands imposed by interactions with virtual objects.\u003c/p\u003e \u003cp\u003eVideo analysis indicated that, during the reaching phase, movements were predominantly characterized by shoulder flexion and abduction combined with elbow extension, enabling hand transport toward the target. During the prehension preparation phase, fine adjustments in hand positioning were observed, involving forearm pronation or supination and subtle wrist flexion and extension movements. At the moment of grasping, finger flexion and wrist stabilization occurred, requiring coordinated activation of intrinsic and extrinsic hand muscles. During item manipulation, precise and coordinated finger movements were required, accompanied by postural adjustments of the shoulder and elbow to maintain grip stability and proximal control (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eJoint movements and motor demands identified in the \u003cem\u003eVirtual Mente\u003c/em\u003e game tasks.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCore Task\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePhase\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eShoulder\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eElbow\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eWrist\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eFingers\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eREACHING TASK\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eInitiation\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFlexion;\u003c/p\u003e \u003cp\u003eAbduction; External rotation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eExtension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFlexion; Extension; Pronation; Supination\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eFlexion; Extension\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eExecution\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFlexion; Abduction;\u003c/p\u003e \u003cp\u003eExternal rotation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eExtension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFlexion; Extension; Pronation; Supination\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eFlexion; Extension\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eTermination\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFlexion; Abduction; External rotation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eExtension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFlexion; Extension; Pronation; Supination\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eFlexion; Extension\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eGRASPING TASK\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eInitiation\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFlexion; Abduction; Adduction; Internal rotation; External rotation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFlexion; Extension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFlexion; Extension; Pronation; Supination; Ulnar deviation; Radial deviation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eFlexion; Extension; Abduction; Adduction; Thumb opposition\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eExecution\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFlexion; Abduction; Adduction; Internal rotation; External rotation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFlexion; Extension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFlexion; Extension; Pronation; Supination; Ulnar deviation; Radial deviation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eFlexion; Extension; Abduction; Adduction; Thumb opposition\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eTermination\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFlexion; Abduction; Adduction; Internal rotation; External rotation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFlexion; Extension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFlexion; Extension; Pronation; Supination; Ulnar deviation; Radial deviation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eFlexion; Extension; Abduction; Adduction; Thumb opposition\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eMANIPULATION TASK\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eInitiation\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFlexion; Extension; Abduction; Adduction; Internal rotation; External rotation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFlexion; Extension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFlexion; Extension; Pronation; Supination; Ulnar deviation; Radial deviation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eFlexion; Extension; Abduction; Adduction; Thumb opposition\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eExecution\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFlexion; Extension; Abduction; Adduction; Internal rotation; External rotation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFlexion; Extension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFlexion; Extension; Pronation; Supination; Ulnar deviation; Radial deviation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eFlexion; Extension; Abduction; Adduction; Thumb opposition\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eTermination\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFlexion; Extension; Abduction; Adduction; Internal rotation; External rotation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFlexion; Extension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFlexion; Extension; Pronation; Supination; Ulnar deviation; Radial deviation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eFlexion; Extension; Abduction; Adduction; Thumb opposition\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e\u003cstrong\u003eNote:\u003c/strong\u003e Shoulder, elbow, wrist, and finger movements required for reaching, grasping, and manipulation tasks were analyzed across task phases (initiation, execution, and termination), based on the model proposed by Hedman [28].\u003c/p\u003e\u003cp\u003eThis analysis also revealed limitations of the original game for motor training purposes. Although the original version incorporated reaching, grasping, and manipulation actions, the tasks did not provide sufficient biomechanical challenges for post-stroke individuals. The activities exhibited limited variability in range of motion, lacked spatial variation of targets, imposed low demands on trunk and upper-limb dissociation, required minimal pronation and supination movements, and relied on relatively simple interaction tasks with limited potential to promote neural adaptation. These findings highlighted the need for structural modifications to ensure that the game could generate motor stimuli aligned with the therapeutic goals of upper-limb rehabilitation.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eApplication of motor learning principles\u003c/h2\u003e \u003cp\u003eAfter identifying the motor demands with task execution in the game, motor learning principles were considered to guide the adaptation of the system for upper-limb reaching training in post-stroke individuals. The literature describes four primary mechanisms that contribute to motor learning: use-dependent learning, instruction-based learning, reinforcement learning, and sensorimotor adaptation. In the game context, use-dependent learning is promoted through the repeated execution of reaching, grasping, and manipulation actions involving virtual objects. Instruction-based learning is conveyed through visual and auditory cues, as well as performance-related feedback provided to the user during interaction with the virtual environment. Reinforcement learning occurs through success and error signals and progression between phases that inform users about their performance. Finally, sensorimotor adaptation is triggered when users must adjust their movements in response to changes in the virtual environment, such as item location, response timing, or interaction dynamics [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe logic of the original game version already incorporated some fundamental motor learning mechanisms, such as task-oriented practice combined with immediate visual and auditory feedback. These elements allow users to monitor their performance and adjust movements during task execution, supporting the formation of stable motor memories and facilitating neural plasticity processes essential for motor recovery after stroke [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. However, functional analysis of the original version revealed important limitations, particularly the need to increase the number of targets and introduce randomization in object presentation to strengthen key elements associated with neural reorganization in post-stroke individuals.\u003c/p\u003e \u003cp\u003eIncreasing the number of targets was considered essential to enhance motor exploration. New targets were therefore added at different spatial locations on the table, enabling multitarget reaching and stimulating movements across multiple directions, ranges of motion, and joint combinations. This modification enriched the diversity of trained motor patterns and expanded the functional motor repertoire required for post-stroke recovery. In addition, randomization of object presentation disrupted predictable movement sequences, increased cognitive-motor demands, and strengthened sensorimotor adaptation processes, thereby contributing to cortical reorganization and improved generalization of motor learning [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eBased on these considerations, the developers implemented a new game phase. The original version was maintained as Phase 1, while Phase 2 incorporated additional motor demands. Although the virtual environment remained unchanged, five additional plates were introduced, resulting in a total of nine targets distributed according to the model adapted from Stewart\u0026rsquo;s study [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. The increased number of targets promoted greater movement variability by encouraging reaching across multiple directions, ranges of motion, and joint combinations. Additionally, 14 different types of fruits and vegetables were introduced and randomly distributed across two trays positioned at the left and right corners of the table, facilitating bilateral training and enabling task execution with either upper limb.\u003c/p\u003e \u003cp\u003eThis adaptation aimed to increase the complexity of the reaching task by establishing a graded progression of difficulty. Targets located closer to the user require smaller joint excursions and lower motor effort compared with more distant targets. Similarly, targets positioned on the ipsilateral side of the affected limb allow gradual increases in reaching difficulty. To further introduce practice variability, a randomization model was applied to object placement on the targets, ensuring that the arrangement changes at the beginning of each phase and thereby increasing task complexity and variability (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eStrategies to ensure user sensory comfort\u003c/h2\u003e \u003cp\u003eAudiovisual adaptations of the VR environment were also implemented to enhance user comfort and reduce the risk of sensory discomfort during gameplay. Factors influencing sensory discomfort during VR exposure are commonly grouped into three main categories: content-related factors, hardware-related factors, and user-related characteristics. Content-related factors include the design of visual elements as well as camera movement, speed, and direction within the virtual environment. Hardware-related factors involve characteristics such as display type, field of view, interaction range, and frame rate. Finally, user-related factors include individual characteristics such as sex, age, prior VR experience, susceptibility to motion sickness, and duration of exposure to the virtual experience [\u003cspan additionalcitationids=\"CR37 CR38\" citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSensory discomfort associated with VR exposure, commonly referred to as cybersickness, is characterized by symptoms such as sweating, yawning, dizziness, spatial disorientation, fatigue, nausea, and vomiting during or after exposure to virtual environments [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e, \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e]. Among the theoretical explanations for these symptoms, sensory conflict theory proposes that cybersickness arises from a mismatch between incoming sensory information and prior bodily experiences [\u003cspan additionalcitationids=\"CR43\" citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e]. In contrast, multisensory reweighting theory suggests that these symptoms may result from discrepancies between expected and perceived sensory stimuli, indicating that susceptibility to cybersickness may depend on an individual\u0026rsquo;s capacity to rapidly resolve conflicting multisensory signals generated during VR interaction [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eBased on these considerations, several adaptations were implemented in the game to improve sensory comfort (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). These modifications included adjustments to lighting, sound, and visual design, such as adding focused lighting over the table, reducing background scene brightness, balancing sound effects, and using lower-contrast colors schemes. These modifications are particularly relevant for post-stroke individuals, who often exhibit increased sensitivity to brightness and contrast, slowed sensory integration, susceptibility to spatial disorientation, and increased visual or cognitive fatigue. By reducing peripheral stimuli, stabilizing the virtual environment, and minimizing sensory overload, these adaptations improve tolerability for users with lower sensory thresholds, decrease the risk of cybersickness, and enhance the safety, comfort, and clinical feasibility of using the game in rehabilitation [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e, \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eSecond game adaptation\u003c/h2\u003e \u003cdiv id=\"Sec15\" class=\"Section3\"\u003e \u003ch2\u003eFinal testing and technical improvements of the game\u0026rsquo;s final version\u003c/h2\u003e \u003cp\u003eAfter receiving the new version of \u003cem\u003eVirtual Mente\u003c/em\u003e, which incorporated the proposed adaptations, redesign, and creation of Phase 2, additional internal testing was conducted by members of the LIPERV research team following the same exploratory procedures adopted in the previous testing stage. During this stage, new demands related to Phase 2 were identified, particularly regarding object design, correction of additional bugs, interaction challenges, platform connectivity, and synchronization between real-world movements and their virtual representations. Observations from this phase informed final adjustments to optimize the user experience, improve fidelity between real and virtual motor execution, and prepare the prototype for expert validation.\u003c/p\u003e \u003cp\u003eKey outcomes encompassed various aspects of the game and web platform. For the platform and connectivity, improvements included the addition of filters to locate or exclude users on the web platform, as well as enhancements in device connectivity and synchronization. Concerning the game environment design, corrections were requested for the textures and shapes of fruits and vegetables, adjustments to plate design, and modifications to the light\u0026ndash;dark contrast within the game environment. Regarding game initiation, interactivity, and completion, adjustments included object manipulation, adaptations of virtual hand visualization according to grasp type (pinch and palmar), improvements in the logic for object placement on the plates, and a reduction in waiting time between the end of one phase and the start of the next.\u003c/p\u003e \u003cp\u003eFor bug correction, issues were identified in object interactions during manipulation, errors in counting hits and mistakes within the game, and inconsistencies in the virtual environment when generating or resuming the same phase. Finally, additional recommendations included replacing the chair design with a standard dining chair model, creating an informational panel for the user to display data on phase duration, number of errors, successes, and final percentage, and modifying object presentation on the targets using translucent images positioned above each plate.\u003c/p\u003e \u003cp\u003eThe new improvement demands for Phase 2 targeted key aspects of the clinical applicability of VR games for post-stroke rehabilitation. Accordingly, the adjustment of the synchronization and tracking of user movements in the real environment and their corresponding representation in the virtual environment can minimize perceptual\u0026ndash;motor discrepancies, ensuring that accurate feedback is provided for each action, which is essential for promoting motor learning processes [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Similarly, modifications to contrast, lighting, and visual stability of the scenario can reduce perceptual fatigue and prevent the sensory overload commonly experienced by post-stroke individuals [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e, \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e, \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eBy controlling these aspects, the virtual environment becomes more tolerable, safe, and functionally oriented toward motor performance, reducing sensory input that can impair motor planning. These adjustments make the game more responsive to the user\u0026rsquo;s motor and sensory needs, allowing therapists to conduct training in a more structured and safe manner, thereby increasing the clinical applicability of VR-based rehabilitation [\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e, \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e]. The latest version of the game prototype was delivered to LIPERV in October 2025 and is currently undergoing testing for content validation and usability assessment by professionals with expertise in computer science and rehabilitation. These procedures correspond to the subsequent phases of the study and aim to evaluate the clarity, relevance, and usability of the system before its application with end users.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eTheoretical perspectives and evidence on the development and use of serious games in rehabilitation\u003c/h2\u003e \u003cp\u003eThis study describes the functional adaptation and redesign of the \u003cem\u003eVirtual Mente\u003c/em\u003e game, originally developed for cognitive training in older adults and subsequently reconfigured for functional upper-limb training in post-stroke individuals. While retaining the original virtual environment, the game was expanded to include a new phase with additional plates, fruits, vegetables, and trays, thereby increasing interaction opportunities and motor demands. These modifications were implemented collaboratively between developers and researchers through an iterative process guided by clinical and biomechanical principles, resulting in a tool better aligned with the requirements of motor and functional training in individuals with upper-limb impairments.\u003c/p\u003e \u003cp\u003eCurrent frameworks for the development of serious games in rehabilitation emphasize two main axes: the standardization of the design process based on clinical requirements and patient-centered principles, along with the incorporation of motivational elements to enhance therapeutic adherence [\u003cspan additionalcitationids=\"CR11 CR12\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Redesigning IVR serious games for rehabilitation requires integrating kinetic-functional and biomechanical demands into game tasks. In parallel, strategies for sensory comfort within virtual environments must be incorporated to reduce cybersickness symptoms and ensure a clinically oriented and tolerable user experience. Following a framework similar to that proposed by Ambros-Antemate [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], the adaptation of \u003cem\u003eVirtual Mente\u003c/em\u003e adopted an iterative and collaborative workflow between physiotherapists and programmers, ensuring alignment between clinical objectives and game design and reinforcing the practical applicability of conceptual models in the creation and development of IVR serious games.\u003c/p\u003e \u003cp\u003eOne of the theoretical approaches frequently used to understand engagement and motivation in digital rehabilitation games is the Self-Determination Theory [\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e]. This theory proposes that motivated behavior is sustained by the fulfillment of three basic psychological needs: autonomy, competence, and relatedness. Autonomy refers to the perception of control over one\u0026rsquo;s actions, competence emerges from successfully performing appropriately challenging tasks, and relatedness reflects the sense of connection with a meaningful context. In the redesign of \u003cem\u003eVirtual Mente\u003c/em\u003e, these principles were considered to support engagement during training. Direct interaction with game elements encourages a sense of autonomy, progressive increases in task difficulty support the perception of competence, and immersion in a familiar and coherent virtual environment may facilitate the user\u0026rsquo;s sense of connection with the task context.\u003c/p\u003e \u003cp\u003eIn addition to theoretical aspects related to motivation and engagement, the identification and correction of bugs played an important role in the adaptation process of the game for post-stroke individuals. In IVR systems, the integration between hardware and software requires high levels of stability and synchronization to ensure that user actions are accurately represented in the virtual environment [\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e, \u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e]. Addressing technical inconsistencies during the development process therefore contributes to improving interaction reliability and supports the iterative cycles commonly involved in the design and refinement of serious games for rehabilitation. Similarly, considering the joint demands involved in reaching and object manipulation tasks allowed the redesign of game interactions to incorporate movements requiring different ranges of motion and joint combinations. This approach may provide clinicians with observable motor patterns during task execution that could support qualitative observations of motor control during rehabilitation training [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe gamification strategies incorporated into serious games aim to promote and sustain engagement during repetitive motor training tasks. One mechanism frequently discussed in the literature is the promotion of a state of flow, characterized by deep involvement in the activity when task difficulty is balanced with the user\u0026rsquo;s abilities [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. and immediate visual feedback can act as reinforcing signals for correct movement execution. In \u003cem\u003eVirtual Mente\u003c/em\u003e, the use of visual feedback and gradual adjustments in the spatial distribution and distance of reaching targets sought to maintain an appropriate balance between challenge and ability. his approach may help prevent common responses associated with repetitive training, such as boredom when tasks are overly simple or frustration when they are excessively difficult, thereby supporting motivation and engagement during practice and potentially facilitating motor learning processes and neuroplasticity [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eA limitation of this study is that, to date, the validation process has been conducted only internally. Although this approach allowed close alignment with the perspectives of the development and research teams, the absence of usability testing with post-stroke individuals and formal validation by field experts remains an important limitation. The subsequent phases of the study will involve content validation by specialists and usability testing with the target population. These stages aim to evaluate system clarity, usability, and acceptance, as well as to explore its potential effects on upper-limb motor performance in post-stroke individuals.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThis study described the functional adaptation and redesign of the IVR game \u003cem\u003eVirtual Mente\u003c/em\u003e, integrating clinical, biomechanical, and motor learning principles into its redesign to better address the therapeutic demands of upper-limb reaching in post-stroke individuals. The implemented modifications improved aspects related to movement precision, variability of reaching tasks, and sensory conditions within the virtual environment, highlighting the potential applicability of the prototype as a complementary tool for rehabilitation training. Future steps include content validation by experts, usability testing with post-stroke individuals, and the integration of kinematic and clinical measures to further investigate its potential effectiveness and applicability in therapeutic contexts.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eLIPERV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eVirtual Reality Intervention and Research Laboratory\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eNUTES\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eStrategic Health Technologies Center\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eVR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eVirtual Reality\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIVR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eImmersive Virtual Reality\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eUEPB\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eState University of Para\u0026iacute;ba\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eUFRN\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eFederal University of Rio Grande do Norte\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003ch2\u003eEthics approval and consent to participate\u003c/h2\u003e\n\u003cp\u003eThe study related to the redesign and adaptation of the serious game \u003cem\u003eVirtual Mente\u003c/em\u003e for post-stroke individuals was approved by the Research Ethics Committee (CEP) of Federal University of Rio Grande do Norte (UFRN; CAAE: 85298124.6.0000.5537, Opinion No. 7,682,556), and the use and storage of user data from the original version of the game for cognitive training in older adults by Strategic Health Technologies Center (NUTES) was approved by the CEP of State University of Para\u0026iacute;ba (UEPB; CAAE: 81694124.0.0000.5187, Opinion No. 7,020,886).\u003c/p\u003e\n\n\u003ch2\u003eConsent for publication\u003c/h2\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\n\u003ch2\u003eAvailability of data and materials\u003c/h2\u003e\n\u003cp\u003eNo datasets were generated or analyzed during the current study.\u003c/p\u003e\n\n\u003ch2\u003eCompeting interests\u003c/h2\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\n\u003ch2\u003eFunding\u003c/h2\u003e\n\u003cp\u003eThis study was financed in part by the Coordination for the Improvement of Higher Education Personnel (CAPES), Brazil, Finance Code 001.\u003c/p\u003e\n\n\u003ch2\u003eAuthors\u0026rsquo; contributions\u003c/h2\u003e\n\u003cp\u003eLCAC and VLC conceived the study, contributed to the design of the adaptation process, and drafted the manuscript. PESB contributed to the development of the virtual reality system and implementation of game modifications. DJSS and LBAF participated in the methodological design and analysis of the therapeutic framework. LBAF and VLC contributed to data interpretation and critical revision of the manuscript. FACC supervised the study and critically revised the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\n\u003ch2\u003eAcknowledgements\u003c/h2\u003e\n\u003cp\u003eThe authors thank the Postgraduate Program in Physical Therapy at the Federal University of Rio Grande do Norte, Natal, Brazil, for supporting this study. We also thank the Coordination for the Improvement of Higher Education Personnel, Brazil (CAPES), for financial assistance (Finance Code 001).\u003c/p\u003e\n\n\u003ch2\u003eAuthor information\u003c/h2\u003e\n\u003cp\u003e\u0026sup1; PhD student in Physiotherapy, Federal University of Rio Grande do Norte (UFRN), Brazil.\u003c/p\u003e\n\u003cp\u003e\u0026sup2; PhD student in Physiotherapy, Federal University of Rio Grande do Norte (UFRN), Brazil.\u003c/p\u003e\n\u003cp\u003e\u0026sup3; Master\u0026rsquo;s student in Physiotherapy, Federal University of Rio Grande do Norte (UFRN), Brazil.\u003c/p\u003e\n\u003cp\u003e⁴ Resident in Public Health, School of Public Health of Cear\u0026aacute; (ESP/CE), Brazil.\u003c/p\u003e\n\u003cp\u003e⁵ PhD professor, State University of Para\u0026iacute;ba (UEPB), Brazil.\u003c/p\u003e\n\u003cp\u003e⁶ PhD professor, Federal University of Rio Grande do Norte (UFRN), Brazil.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAli AS, Arumugam A, Gururaj S, Sardesai S, Kumaran DS. Effects of game-based rehabilitation on upper limb motor function following acute and sub-acute stroke: a systematic review, meta-analyses, and GRADE evidence synthesis. Virtual Real. 2025;29:79.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLaver KE, Lange B, George S, Deutsch JE, Saposnik G, Chapman M, et al. Virtual reality for stroke rehabilitation. Cochrane Database Syst Rev. 2025;2025:CD008349.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang J, Liu M, Yue J, Yang J, Xiao Y, Yang J, et al. Effects of virtual reality with different modalities on upper limb recovery: a systematic review and network meta-analysis on optimizing stroke rehabilitation. Front Neurol. 2025;16:1544135.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSoleimani M, Ghazisaeedi M, Heydari S. The efficacy of virtual reality for upper limb rehabilitation in stroke patients: a systematic review and meta-analysis. BMC Med Inf Decis Mak. 2024;24:135.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKiper P, Przysiezna E, Cieslik B, Broniec-Siekaniec K, Kucinska A, Szczygiel J, et al. Effects of immersive virtual therapy as a method supporting recovery of depressive symptoms in post-stroke rehabilitation: randomized controlled trial. Clin Interv Aging. 2022;17:1673\u0026ndash;85.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlvarez J, Djaouti D. An introduction to serious game definitions and concepts. In: Proceedings of the Serious Games \u0026amp; Simulation Workshop. 2011.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDoumas I, Everard G, Dehem S, Lejeune T. Serious games for upper limb rehabilitation after stroke: a meta-analysis. J Neuroeng Rehabil. 2021;18:100.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFregna G, Paoluzzi C, Baroni A, Cano-de-la-Cuerda R, Casile A, Straudi S. Head-mounted displays for upper limb stroke rehabilitation: a scoping review. J Clin Med. 2023;12:7444.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBaluz R, Teles A, Fontenele JE, Moreira R, Fialho R, Azevedo P, et al. Motor rehabilitation of upper limbs using a gesture-based serious game: evaluation of usability and user experience. Games Health J. 2022;11:177\u0026ndash;85.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAmbros-Antemate JF, Beristain-Colorado MP, Vargas-Trevi\u0026ntilde;o M, Guti\u0026eacute;rrez-Guti\u0026eacute;rrez J, Hern\u0026aacute;ndez-Cruz PA, Gallegos-Velasco IB, et al. Improving adherence to physical therapy in the development of serious games: conceptual framework design study. JMIR Form Res. 2023;7:e39838.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBeristain-Colorado MP, Ambros-Antemate JF, Vargas-Trevi\u0026ntilde;o M, Guti\u0026eacute;rrez-Guti\u0026eacute;rrez J, Moreno-Rodriguez A, Hern\u0026aacute;ndez-Cruz PA, et al. Standardizing the development of serious games for physical rehabilitation: conceptual framework proposal. JMIR Serious Games. 2021;9:e25854.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXiao Y, Bai H, Gao Y, Hu B, Zheng J, Cai X, et al. Interactive virtual ankle movement controlled by wrist sEMG improves motor imagery: an exploratory study. IEEE Trans Vis Comput Graph. 2024;30:5507\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003evan Gaalen AEJ, Brouwer J, Sch\u0026ouml;nrock-Adema J, Bouwkamp-Timmer T, Jaarsma ADC, Georgiadis JR. Gamification of health professions education: a systematic review. Adv Health Sci Educ Theory Pract. 2021;26:683\u0026ndash;711.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLevin MF, Hiengkaew V, Nilanont Y, Cheung D, Dai D, Shaw J, et al. Relationship between clinical measures of upper limb movement quality and activity poststroke. Neurorehabil Neural Repair. 2019;33:432\u0026ndash;41.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVillepinte C, Verma A, Dimeglio C, De Boissezon X, Gasq D. Responsiveness of kinematic and clinical measures of upper-limb motor function after stroke: a systematic review and meta-analysis. Ann Phys Rehabil Med. 2021;64:101366.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDiriba Kenea C, Gemechu Abessa T, Lamba D, Bonnech\u0026egrave;re B. Technological features of immersive virtual reality systems for upper limb stroke rehabilitation: a systematic review. Sens (Basel). 2024;24:3546.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMelo G, Junior JRZ, Lopes JB, Duarte NAC, Oliveira DAP, Rezende LP, et al. Effects of treadmill and virtual reality gait training on the quality of life of people with Parkinson\u0026rsquo;s disease. Gait Posture. 2024;113:201\u0026ndash;2.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMinelli C, Bazan R, Pedatella MTA, Neves LO, Cacho RO, Magalh\u0026atilde;es SCSA, et al. Brazilian Academy of Neurology practice guidelines for stroke rehabilitation: part I. Arq Neuropsiquiatr. 2022;80:634\u0026ndash;52.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eS\u0026aacute;nchez-Gil JJ, S\u0026aacute;ez-Manzano A, L\u0026oacute;pez-Luque R, Ochoa-Sep\u0026uacute;lveda JJ, Ca\u0026ntilde;ete-Carmona E. Gamified devices for stroke rehabilitation: a systematic review. Comput Methods Programs Biomed. 2025;258:108476.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHerrera V, Albusac J, Castro-Schez JJ, Gonz\u0026aacute;lez-Morcillo C, Monekosso DN, Pacheco S, et al. Creating adapted environments: enhancing accessibility in virtual reality for upper limb rehabilitation through automated element adjustment. Virtual Real. 2025;29:28.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJiao Y, Fermin P, Qi D, Stacey Z, Smith RM, Zhang Y. A clinically oriented VR-based treadmill training system for post-stroke rehabilitation: integration of motor learning and control principles. Virtual Real. 2025;29:112.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChander H, Arachchige SNKK, Hill CM, Turner AJ, Deb S, Shojaei A, et al. Virtual-reality-induced visual perturbations impact postural control system behavior. Behav Sci (Basel). 2019;9:113.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWilson EB, Bergquist JS, Wright WG, Jacobs DA. Gait stability in virtual reality: effects of VR display modality in the presence of visual perturbations. J Neuroeng Rehabil. 2025;22:32.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLippert LS. Clinical kinesiology and anatomy. Philadelphia: Lippincott Williams \u0026amp; Wilkins; 2013.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSahrmann SA. The human movement system: our professional identity. Phys Ther. 2014;94:1034\u0026ndash;42.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSahrmann S, Azevedo DC, Van Dillen L. Diagnosis and treatment of movement system impairment syndromes. Braz J Phys Ther. 2017;21:391\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHedman LD, Quinn L, Gill-Body K, Brown DA, Quiben M, Riley N, et al. White paper: movement system diagnoses in neurologic physical therapy. J Neurol Phys Ther. 2018;42:110\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQuinn L, Riley N, Tyrell CM, Judd DL, Gill-Body KM, Hedman LD, et al. A framework for movement analysis of tasks: recommendations from the Academy of Neurologic Physical Therapy\u0026rsquo;s Movement System Task Force. Phys Ther. 2021;101:pzab154.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZarzycki R, Malloy P, Eckenrode BJ, Fagan J, Malloy M, Mangione KK. Application of the 4-element movement system model to sports physical therapy practice and education. Int J Sports Phys Ther. 2022;17:18\u0026ndash;26.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLeech KA, Roemmich RT, Gordon J, Reisman DS, Cherry-Allen KM. Updates in motor learning: implications for physical therapist practice and education. Phys Ther. 2022;102:pzab250.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcCluskey A, Lannin NA, Schurr K, Dorsch S, Christie LJ. Skills and strategies for improving arm function and occupational participation after acquired brain impairment. In: Curtin M, Egan M, Parnell T, Prior Y, Sauv\u0026eacute;-Schenk D K, et al. editors. Occupational therapy for people experiencing illness, injury or impairment. 8th ed. Edinburgh: Elsevier; 2024. Cezar da Cruz.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDrews R, Pacheco MM, Bastos FH, Tani G. Knowledge of results does not affect self-efficacy and skill acquisition on an anticipatory timing task. J Mot Behav. 2021;53:275\u0026ndash;86.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMatsugi A, Yoshida N, Nakano H, Okada Y. The neurorehabilitation of neurological movement disorders requires rigorous and sustained research. J Clin Med. 2024;13:852.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHanlon RE. Motor learning following unilateral stroke. Arch Phys Med Rehabil. 1996;77:811\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMaier M, Ballester BR, Verschure PFMJ. Principles of neurorehabilitation after stroke based on motor learning and brain plasticity mechanisms. Front Syst Neurosci. 2019;13:74.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStewart JC, Lewthwaite R, Rocktashel J, Winstein CJ. Self-efficacy and reach performance in individuals with mild motor impairment due to stroke. Neurorehabil Neural Repair. 2019;33:319\u0026ndash;28.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim YS, Won JH, Jang SW, Ko J. Effects of cybersickness caused by head-mounted display-based virtual reality on physiological responses: cross-sectional study. JMIR Serious Games. 2022;10:e37938.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLim I, Cha B, Cho DR, Park E, Lee KS, Kim M. Safety and potential usability of immersive virtual reality for brain rehabilitation: a pilot study. Games Health J. 2023;12:34\u0026ndash;41.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOh HJ, Lee GC. Feasibility of full immersive virtual reality video game on balance and cybersickness of healthy adolescents. Neurosci Lett. 2021;760:136063.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePark WD, Jang SW, Kim YH, Kim GA, Son W, Kim YS. A study on cyber sickness reduction by oculo-motor exercise performed immediately prior to viewing virtual reality content on head mounted display. Vibroeng Procedia. 2017;14:260\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGallagher M, Ferr\u0026egrave; ER. Cybersickness: a multisensory integration perspective. Multisens Res. 2018;31:645\u0026ndash;74.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYang Y, Sun X, Zhang Y, Zhang H, Sun X, Yang C, et al. Effects of social interaction on virtual reality cybersickness. Displays. 2023;80:102512.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNam S, Jang KM, Kwon M, Lim HK, Jeong J. Electroencephalogram microstates and functional connectivity of cybersickness. Front Hum Neurosci. 2022;16:857768.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHan X, Ke J, Jiang S, Zhang D. Gaming-based virtual reality therapy for the rehabilitation of upper extremity function after stroke. Chin J Phys Med Rehabil. 2016;12:401\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eda Silva Marinho A, Terton U, Jones CM. Cybersickness and postural stability of first-time VR users playing VR videogames. Appl Ergon. 2022;101:103698.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTosto-Mancuso J, Tabacof L, Herrera JE, Breyman E, Dewil S, Cortes M, et al. Gamified neurorehabilitation strategies for post-stroke motor recovery: challenges and advantages. Curr Neurol Neurosci Rep. 2022;22:183\u0026ndash;95.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVieira C, Pais-Vieira CFS, Novais J, Perrotta A. Serious game design and clinical improvement in physical rehabilitation: systematic review. JMIR Serious Games. 2021;9:e20066.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDiriba Kenea C, Gemechu Abessa T, Lamba D, Bonnech\u0026egrave;re B. AdaptRehab VR: development of an immersive virtual reality system for upper limb stroke rehabilitation designed for low- and middle-income countries using a participatory co-creation approach. Bioeng (Basel). 2025;12:581.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMunoz-Novoa M, Andersson C, Sunnerhagen KS, Alt Murphy M. A novel intervention for upper limb rehabilitation in people with stroke combining myoelectric pattern recognition, virtual reality, and serious gaming: a qualitative study. Disabil Rehabil. 2025;47:3930\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eUysal A, Yildirim IG. Self-determination theory in digital games. In: Bostan B, editor. Gamer psychology and behavior. Cham: Springer; 2016.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlMousa M, Al-Khalifa HS, AlSobayel H. Requirements elicitation and prototyping of a fully immersive virtual reality gaming system for upper limb stroke rehabilitation in Saudi Arabia. Mob Inf Syst. 2017;2017:1\u0026ndash;12.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTurolla A, Dam M, Ventura L, et al. Virtual reality for the rehabilitation of the upper limb motor function after stroke: a prospective controlled trial. J Neuroeng Rehabil. 2013;10:85.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMuratori LM, Lamberg EM, Quinn L, Duff SV. Applying principles of motor learning and control to upper extremity rehabilitation. J Hand Ther. 2013;26:94\u0026ndash;103.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-neuroengineering-and-rehabilitation","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jner","sideBox":"Learn more about [Journal of NeuroEngineering and Rehabilitation](http://jneuroengrehab.biomedcentral.com/)","snPcode":"12984","submissionUrl":"https://submission.nature.com/new-submission/12984/3","title":"Journal of NeuroEngineering and Rehabilitation","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Virtual Reality, Upper Extremity, Serious Games, Rehabilitation, Stroke","lastPublishedDoi":"10.21203/rs.3.rs-9152421/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9152421/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eVirtual reality, particularly through the use of serious games, has emerged as a promising strategy in post-stroke rehabilitation. Adapting existing serious games may represent a viable approach to tailoring interventions to the motor demands of specific populations. Accordingly, this study described the adaptation and redesign process of an immersive virtual reality game, \u003cem\u003eVirtual Mente\u003c/em\u003e, originally developed for cognitive training in older adults, for upper-limb reaching training in post-stroke individuals.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis descriptive study outlined the functional adaptation and redesign process of the \u003cem\u003eVirtual Mente\u003c/em\u003e serious game for a new target population. The methodological process was divided into three main stages: (1) description and analysis of the therapeutic potential of the original game version; (2) implementation of initial adjustments and adaptations based on internal testing and iterative discussions between researchers and developers; and (3) final testing and technical refinement of the adapted version.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eFollowing meetings between developers and researchers conducted from November 2023 to October 2025, three primary adaptation axes were identified: (1) biomechanical and kinematic adjustments of movements related to task execution; (2) application of motor learning principles to enable upper-limb reaching training in post-stroke individuals; and (3) implementation of strategies to ensure user sensory comfort during immersive virtual reality exposure. These adaptations resulted in the redesign of game interactions, including the creation of a new phase with additional targets and objects, increased movement variability, and audiovisual modifications to improve interaction and sensory tolerability.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eThe adaptation process enabled the redesign of \u003cem\u003eVirtual Mente\u003c/em\u003e into a prototype with characteristics more consistent with the therapeutic demands of upper-limb reaching training after stroke. By integrating clinical, biomechanical, and motor learning principles, the adapted version may represent a promising complementary tool for rehabilitation training in immersive virtual reality. Future steps include content validation by experts and usability testing with post-stroke individuals.\u003c/p\u003e","manuscriptTitle":"Adaptation of an immersive virtual reality serious game prototype for upper limb function training in post-stroke individuals: innovations and clinical applications","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-23 23:24:12","doi":"10.21203/rs.3.rs-9152421/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-05-04T15:26:06+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"300619152658713644641191758629020088541","date":"2026-04-20T12:05:40+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-16T07:08:18+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-18T14:10:19+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-18T13:43:31+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of NeuroEngineering and Rehabilitation","date":"2026-03-17T20:37:38+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-neuroengineering-and-rehabilitation","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jner","sideBox":"Learn more about [Journal of NeuroEngineering and Rehabilitation](http://jneuroengrehab.biomedcentral.com/)","snPcode":"12984","submissionUrl":"https://submission.nature.com/new-submission/12984/3","title":"Journal of NeuroEngineering and Rehabilitation","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"36cbd0a9-961e-4333-83f9-a0402632ce95","owner":[],"postedDate":"April 23rd, 2026","published":true,"recentEditorialEvents":[{"type":"editorInvitedReview","content":"","date":"2026-05-04T15:26:06+00:00","index":22,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-23T23:24:12+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-23 23:24:12","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9152421","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9152421","identity":"rs-9152421","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}