The Adapted Characteristic in the Range of Motion of the Shoulder for Young Male Volleyball Players

The Adapted Characteristic in the Range of Motion of the Shoulder for Young Male Volleyball Players | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article The Adapted Characteristic in the Range of Motion of the Shoulder for Young Male Volleyball Players Kun-Yu Chou, Wan-Ling Wu, Chun-Wen Chiu, Shih-Chung Cheng, Hsiao-Yun Chang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5262561/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Volleyball players often repeatedly perform spiking and serving, which may lead to muscle microtrauma of the shoulder and consequently reduce shoulder joint range of motion (ROM) and increase the risk of shoulder injuries. Aims This study aimed to understand and evaluate the bilateral shoulder ROM in high school male volleyball athletes to discover the adapted characteristics. Methods Forty high school male volleyball athletes participated in this study. The shoulder ROM measurements were taken for both the dominant and non-dominant sides. The paired samples t-tests were used to analyze shoulder ROM differences between the dominant and non-dominant sides. Results The dominant side showed a significantly lower in internal rotation ( p = .000) and total shoulder rotation ROM ( p = .021) compared to the non-dominant side ( p < .05). Conversely, the dominant side of the shoulder exhibited significantly greater external rotation ( p = .001) and shoulder horizontal adduction ( p = .000) than the non-dominant side ( p < .05). No significant differences were found in other measured parameters. The incidence of Glenohumeral Internal Rotation Deficit (GIRD) among all subjects was 37.5%. Conclusions High school male volleyball athletes in this study exhibited tightness in the posterior shoulder of their dominant side, indicating specific adaptations in shoulder ROM and a considerable prevalence of GIRD, observed in approximately one-quarter of the athletes. It is recommended to incorporate stretching and eccentric muscle training focusing on the posterior shoulder to mitigate these adaptations and reduce the risk of shoulder injuries. Overhead sports Flexibility Shoulder injury Glenohumeral Internal Rotation Deficit Figures Figure 1 Introduction Volleyball is an overhead sport with high-frequency usage of spiking and serving movements. The volleyball players are expected to maximize the external rotation angle of shoulder to prolong the acceleration distance of their spikes or serves for higher speed and power [ 1 ]. During an attack, the arm swing speed of volleyball players may reach 100 km/h [ 2 ]. In such a movement pattern, the key factor of maintaining the glenohumeral head stabilizer inside the joint fossa heavily relies on the surrounding soft tissues and muscles in charge of movement control [ 3 ]. The fast arm swing speed and the frequent repetition of spiking and serving movements make volleyball players prone to shoulder injuries [ 4 ]. However, most re-search on sports injuries in volleyball players focused on the knee and ankle, while the shoulder received relatively less attention. Kyle et al. reported that shoulder injuries account for 12.2% of volleyball-related injuries [ 4 ]; another study indicated that the prevalence of shoulder injuries among volleyball players was up to 24% [ 5 ]. These findings have shown us the significant risk of shoulder injuries among volleyball players, which is a non-negligible issue. Additionally, the musculoskeletal system of adolescents is still in the growing phase, and the development of the upper limb musculoskeletal system is usually completed around 22–25 years of age [ 6 – 7 ]. The extensive training involving overhead movements can further increase the risk of shoulder injuries. Previous research has shown that high-intensity training in adolescent athletes may lead to abnormalities in shoulder mobility, skeletal growth, and muscles/tendons pathological changes in the upper limbs. These abnormalities can result in shoulder tendinitis, scapular dyskinesis, and lower back pain [ 8 – 9 ]. Frisch et al. found that 40% of high school female volleyball players experienced non-traumatic shoulder pain, but only 33% took rest [ 10 ]. However, there is limited research on the risk factors related to shoulder injuries in adolescent volleyball players’ intrinsic factors, such as joint mobility and muscle strength. It is critical to address the issue of shoulder injuries and the associated risk factors in this population. Glenohumeral internal rotation deficiency (GIRD) is one of the risk factors for shoulder injuries [ 11 – 12 ]. GIRD occurs in overhead athletes due to the eccentric con-traction of soft tissues in the posterior shoulder during the deceleration phase of the arm swing, leading to microtrauma and subsequent tightness of these tissues [ 11 , 13 – 14 ]. The study by Mizoguchi et al. showed that 38% of young volleyball players experienced a reduction in the internal rotation range of motion (ROM) and total rotation range of motion (TROM) of the dominant shoulder [ 15 ]. Previous studies have indicated that posterior shoulder tightness may lead to a decrease in shoulder horizontal adduction and internal rotation ROM, as well as an increase in external rotation ROM, which may all be contributing to the development of GIRD [ 16 – 17 ]. Manske et al. differentiated GIRD into two categories: normal GIRD, commonly seen in overhead athletes, described as a reduction in internal rotation less than 18 degrees, and a symmetrical bilateral TROM reduction; the other is pathological GIRD, characterized by a reduction in internal rotation greater than 18 degrees and a reduction in dominant shoulder TROM greater than 5 degrees [ 12 ]. They also noted that reduced TROM and external rotation might increase the risk of shoulder injuries. Schmalzl et al. found that in adult volleyball players, GIRD of less than 10 degrees was significantly associated with shoulder impingement and decreased TROM [ 18 ]. Alqarni et al. reported that players with a history of shoulder pain had larger ROM differences in GIRD and TROM than those without a history of shoulder pain [ 19 ]. These findings suggest that a reduction in TROM often accompanies GIRD and is significantly correlated with shoulder pain. Hence, understanding these adaptive changes is of utmost importance for preventing and treating shoulder injuries in adolescent volleyball players. Therefore, the purpose of this study was to assess the bilateral shoulder in high school male volleyball athletes. Methods Study Design and Participate This study is a prospective cross-sectional study. During the preseason phase of the 2023 season, data on bilateral shoulders were collected from volleyball players. The subjects in this study were players from the top four teams in the ranking of the Taiwan High School Volleyball League (HVL). A total of 40 high school male volleyball athletes participated in the study. Among the participants, 34 were right-handed and 6 were left-handed. The participants' average age was 17.7 ± 0.93 years, average height was 180.0 ± 5.91 cm, average weight was 71.1 ± 7.47 kg, and average volleyball experience was 6.5 ± 2.56 years. Inclusion criteria were: no history of upper limb injury, fracture, dislocation, subluxation, or any neurological disorders in the past year; negative results on special shoulder tests administered by a physical therapist; and a minimum training load of four days per week in addition to at least three years of specialized training in volleyball. All participants were informed about the experimental procedures, and both participants and their parents signed the informed consent forms. The study protocol adhered to the Declaration of Helsinki and was approved by the Human Research Ethics Committee of Fu Jen Catholic University in Taiwan (IRB No: FJU-IRB C110139). Procedure This study was conducted with an iPhone 12 Pro Max (Apple Inc., Cupertino, CA), recording videos (1080 HD/60 fps) of the active ROM of the shoulder. The videos were then analyzed using Kinovea software (Version 0.9.5; Kinovea open source project, www.kinovea.org ) to measure the ROM. The shoulder ROM tests included measurements of shoulder hyper-extension (SE), shoulder flexion (SF), internal rotation (IR), external rotation (ER), horizontal adduction (Sadd), and horizontal abduction (Sabd) (Fig. 1 ). All measurements underwent test-retest reliability assessments before the formal pilot testing, with reliability coefficients ranging from 0.984 to 0.998 (SE: 0.984, SF: 0.993, IR: 0.997, ER: 0.991, TROM: 0.993, Sadd: 0.998, and Sabd: 0.995). Both the dominant and non-dominant sides were tested randomly. In this study, the dominant hand was defined as the upper limb used by the volleyball player for attacking movements. All measurements and data collection were performed by one researcher; each measuring item was tested twice and the average value was used for further statistical analysis. All tests were conducted indoors gym. Participants performed a 15-minute warm-up, including jogging and stretching. After warming up, participants drew lots to determine the order of testing and then had their shoulder ROM measured in sequence. There was a 5-minute rest period between each measurement item. Shoulder Hyper-Extension Measurement (Fig. 1 a): The participant lay supine on a platform with the arm positioned alongside the body. The researcher manually stabilized the scapula. The participant then moved the arm posteriorly to its limit. Upon reaching the maximal extension, the video recording was stopped. The video was then analyzed using Kinovea to measure the joint angle. The shoulder joint center was used as the axis to draw two straight lines: one parallel to the lateral midline of the trunk and the other parallel to the midline of the humerus. The angle between these two lines was recorded as the shoulder hyper-extension angle [ 20 ]. Shoulder Flexion Measurement (Fig. 1 b): The participant lay supine on a platform with the arm positioned alongside the body. The researcher manually stabilized the scapula. The participant then raised the arm overhead into flexion to the maximal possible degree. Upon reaching maximal flexion, the video recording was stopped. The video was then analyzed using Kinovea to measure the joint angle. The shoulder joint center was used as the axis to draw two lines: one parallel to the lateral midline of the trunk and the other parallel to the midline of the humerus. The angle between these two lines was recorded as the shoulder flexion angle [ 20 ]. Shoulder Internal/External Rotation Measurement (Fig. 1 c & d): The participant lay supine on a platform with the shoulder abducted to 90 degrees, the elbow flexed to 90 degrees, and the forearm positioned with the palm facing down. For in-ternal rotation, the participant moved the arm towards the feet till the end range. Up-on reaching maximal internal rotation, the video recording was stopped. The video was then analyzed using Kinovea to measure the joint angle. Olecranon was used as the axis, two lines were drawn: one perpendicular to the ground and the other parallel to the longitudinal axis of the ulna. The angle between these two lines was recorded as the shoulder internal rotation angle [ 20 ]. For external rotation, the participant's fore-arm was again positioned with the palm facing down, and the participant moved the arm towards the head to the maximal limit. Upon reaching maximal external rotation, the video recording was stopped. The video was then analyzed using Kinovea to measure the joint angle. Using the olecranon as the axis, two lines were drawn: one perpendicular to the ground and the other parallel to the longitudinal axis of the ulna. The angle between these two lines was recorded as the shoulder external rotation angle [ 20 ]. Shoulder Horizontal Adduction Measurement (Fig. 1 d): The participant lay supine on a platform while the researcher manually stabilized the scapula. The participant then moved the arm horizontally across the chest towards the opposite shoulder to the maximal limit. Upon reaching maximal horizontal adduction, the video recording was stopped. The video was then analyzed using Kinovea to measure the joint angle. Using the acromion as the axis, two straight lines were drawn: one parallel to the top of the shoulder and the other parallel to the longitudinal axis of the humerus. The angle between these two lines was recorded as the shoulder horizontal adduction angle [ 21 ]. This measurement assesses the flexibility of the posterior shoulder; a larger angle indicates greater tightness in the posterior shoulder. Shoulder Horizontal Abduction Measurement (Fig. 1 e): The participant lay supine on a platform with the shoulder abducted to 90 degrees. The participant then moved the arm horizontally and posteriorly to the maximal limit. Upon reaching maximal horizontal abduction, the video recording was stopped. The video was then analyzed using Kinovea to measure the joint angle. Using the acromion as the axis, two straight lines were drawn: one parallel to the top of the shoulder and the other parallel to the longitudinal axis of the humerus. The angle between these two lines was recorded as the shoulder horizontal abduction angle [ 21 ]. This measurement assesses the flexibility of the anterior shoulder, specifically the pectoralis muscle; a larger angle indicates greater anterior shoulder flexibility. After completing the measurements, the total rotational range of motion (TROM) and glenohumeral internal rotation deficit (GIRD) were calculated using the participants' shoulder internal and external rotation data. The formula for TROM is as follows: TROM = Shoulder Internal Rotation (IR) + Shoulder External Rotation (ER) The GIRD was determined using the following criteria: if the difference between the non-dominant side's internal rotation and the dominant side's internal rotation was greater than 10 degrees, and the difference between the non-dominant side's TROM and the dominant side's TROM was greater than 5 degrees, the participant was classified as having GIRD [ 15 ]. ~~~~~~Please insert Fig. 1 here~~~~ Statistical Analysis The data was analyzed using SPSS 20.0 for Windows (IBM Corp., Armonk, NY). Descriptive statistics, including mean and standard deviation (SD), were presented. The Shapiro-Wilk test was conducted to assess the normality of the data. If both groups exhibited a normal distribution, a paired-sample t-test was used to compare the differences in shoulder ROM between the dominant and non-dominant sides of the participants; if exhibited otherwise, the Wilcoxon signed-rank test was employed for the analysis. Finally, Cohen’s d was calculated to determine the effect size, with 0.2 indicating a small effect, 0.5 a medium effect, and 0.8 a large effect. The significance level (α) was set at 0.05. Results This study compared the shoulder ROM between the dominant and non-dominant sides of high school male volleyball players, with the results shown in Table 1 . The findings indicated that IR on the dominant side was significantly less than on the non-dominant side by 9.97 ± 10.25 degrees ( p = .000, Cohen's d = 0.92). The TROM on the dominant side was significantly less than on the non-dominant side by 4.85 ± 12.72 degrees ( p = .021, Cohen's d = 0.37). ER on the dominant side was significantly greater than on the non-dominant side by 5.13 ± 9.1 degrees ( p = .001, Cohen's d = 0.57). Sadd on the dominant side was significantly greater than on the non-dominant side by 5.27 ± 6.50 degrees ( p = .000, Cohen's d = 0.69). The other parameters failed to reach statistical significance, including SE ( p = .106, Cohen's d = 0.24), SF ( p = .368, Cohen's d = 0.07), and Sabd ( p = .417, Cohen's d = 0.08). Table 1 Shoulder range of motion results ROM Dominant Side Non-dominant Side Difference between the bilateral side # p Cohen’s d Mean ± SD Mean ± SD Mean ± SD SE 51.43 ± 4.60 52.74 ± 6.44 -1.31 ± 5.03 .106 0.24 SF 177.55 ± 9.00 178.17 ± 8.04 -0.62 ± 4.32 .368 0.07 IR 42.17 ± 11.23 52.14 ± 10.46 -9.97 ± 10.25 .000* 0.92 ER 94.96 ± 10.02 89.83 ± 7.84 5.13 ± 9.10 .001* 0.57 TROM 137.11 ± 13.09 141.96 ± 13.22 -4.85 ± 12.72 .021* 0.37 Sadd 44.87 ± 8.10 39.60 ± 7.24 5.27 ± 6.50 .000* 0.69 Sabd 216.46 ± 10.08 215.52 ± 11.38 0.94 ± 7.15 .417 0.08 Note: Unit: degree; SE: Shoulder Hyper-Extension; SF: Shoulder Flexion; IR: Internal Rotation; ER: External rotation; TROM: Total Rotational Range of Motion; Sadd: Shoulder Horizontal Adduction; Sabd: Shoulder Horizontal Abduction; * p < .05; Cohen’s d ≤ 2 means low effects, 2 5 means high effects; # Difference between the bilateral side means ROM of Dominant Side minus Non-dominant Side. Among the 40 participants, 15 met the criteria for GIRD, indicating that 37.5% of the subjects had GIRD. The shoulder ROM performance of those with GIRD is shown in Table 2 . For the GIRD group, IR and TROM on the dominant side were significantly less than on the non-dominant side, IR was less by 18.68 ± 7.23 degrees ( p = .000, Cohen's d = 1.72), and TROM was less by 17.32 ± 10.25 degrees ( p = .000, Cohen's d = 1.37). Additionally, Sadd on the dominant side was significantly greater by 6.71 ± 6.87 degrees ( p = .002, Cohen's d = 0.88). The other parameters did not reach statistical significance, including SE ( p = .817, Cohen's d = 0.07), SF ( p = .245, Cohen's d = 0.17), ER ( p = .543, Cohen's d = 0.15), and Sabd ( p = .656, Cohen's d = 0.05). Table 2 GIRD athletes’ shoulder range of motion results ROM Non-GIRD GIRD Mean ± SD p Cohen’s d Mean ± SD p Cohen’s d SE Dominant 52.25 ± 4.75 .035* 0.35 50.05 ± 4.14 .817 0.07 Non-dominant 54.13 ± 5.51 50.43 ± 7.37 SF Dominant 177.11 ± 9.53 .726 § 0.01 178.29 ± 8.30 .245 0.17 Non-dominant 177.25 ± 7.90 179.71 ± 8.31 IR Dominant 44.69 ± 10.87 .007* 0.47 37.95 ± 10.87 .000* 1.72 Non-dominant 49.45 ± 9.54 56.63 ± 10.68 ER Dominant 96.21 ± 9.46 .000* 0.84 92.87 ± 10.89 .543 0.15 Non-dominant 88.83 ± 8.10 91.51 ± 7.35 TROM Dominant 140.88 ± 11.81 .056 0.21 130.81 ± 13.06 .000* 1.37 Non-dominant 138.26 ± 12.66 148.13 ± 12.12 Sadd Dominant 43.30 ± 8.05 .002* 0.58 47.49 ± 7.74 .002* 0.88 Non-dominant 38.90 ± 7.07 40.78 ± 7.61 Sabd Dominant 218.80 ± 8.59 .257 0.20 212.71 ± 11.41 .656 0.05 Non-dominant 216.89 ± 10.07 213.33 ± 13.29 Note: Unit: degree; GIRD: glenohumeral internal rotation deficit; SE: Shoulder Hyper-Extension; SF: Shoulder Flexion; IR: Internal Rotation; ER: External rotation; TROM: Total Rotational Range of Motion; Sadd: Shoulder Horizontal Adduction; Sabd: Shoulder Horizontal Abduction; * p < .05; Cohen’s d ≤ 2 means low effects; 2 5 means high effects; § This parameter was using Wilcoxon signed-rank test to analyzed. ~~~~~~Please insert Table 1 and Table 2 here~~~~ Discussion This study aimed to evaluate the shoulder ROM in high school male volleyball players. The results showed that the dominant side had significantly less internal rotation and total rotational ROM than the non-dominant side, while the dominant side had significantly greater external rotation and shoulder horizontal adduction. Previous research indicated that overhead athletes often develop posterior shoulder tightness due to long-term overhead arm movements, leading to increased Sadd and decreased IR [ 16 – 17 ], which is consistent with our findings. These results might be due to shoulder adaptations caused by overuse, resulting in posterior shoulder tightness. Past research on volleyball players has paid little attention to Sadd and posterior shoulder tightness. However, our study observed that the Sadd of the dominant hand in high school male volleyball players was significantly greater than that of the non-dominant arm. Vad et al. found a high correlation between reduced IR and shoulder injuries and pain [ 22 ]. That means greater Sadd ROM and posterior shoulder tightness may be the risk factors of shoulder injury for youth volleyball players. To prevent such conditions, stretching exercises targeting the posterior shoulder muscles for youth volleyball players to maintain appropriate shoulder ROM. The results of this study found that the dominant side of our participants exhibited significant decreases in internal rotation (IR) and increases in external rotation (ER), similar to findings in previous studies on adolescent volleyball players [ 23 ]. Additionally, research by Schmalzl et al. on handball and volleyball players reported similar results [ 18 ]. Previous studies have also indicated that overhead athletes often experience decreased IR, accompanied by increased ER and reduced total rotational range of motion (TROM) [ 24 – 25 ], which aligns with our findings. However, Mizoguchi et al. found that adolescent volleyball players had significantly increased ER and decreased IR, but no significant difference in TROM, partially aligning with our results [ 26 ]. In volleyball, players ought to achieve maximum external rotation of the shoulder to enhance the power and speed of their attacks and serve [ 1 ]. Repeated volleyball attacks and serve would lead to increased ER. It may also cause pathological changes in the shoulder. This condition can be managed by sleeper stretch and strengthening the shoulder external rotators, especially the eccentric muscles, as a preventive strategy to reduce the risk of shoulder injuries [ 24 ]. This study further investigated the incidence of GIRD among youth volleyball players, finding it to be 37.5%. Previous studies on adolescent volleyball players have reported GIRD incidence rates of 38.2% [ 26 ] and 38.5% [ 23 ], which are similar to our findings. Additionally, Schmalzl et al. reported an even higher incidence rate of 72% in male adult handball and volleyball players [ 18 ]. Past research has indicated that volleyball players with GIRD often experience increased ER and decreased TROM [ 23 – 24 ], which conforms with our results. However, Mizoguchi et al. found that adolescent volleyball players with GIRD exhibited significant decreases in both ER and TROM, partially matching up with our findings [ 26 ]. Previous studies have suggested that increased ER in the dominant hand is a specific adaptation in overhead athletes, allowing for better athletic performance [ 27 – 28 ]. The difference between adult and adolescent players may come from the accumulation of tissue micro-damage caused by long-term training and repeated overhead movements in adults. Research has indicated that athletes with GIRD who continue to train may experience shoulder pain and an increased risk of injury [ 26 – 28 ], leading to absence from practices and competitions. However, this situation has also been found in the youth players in this study. This means that changes and adaptations in shoulder ROM need to be monitored starting with youth players. This study did not find significant differences in the SE, SF, and Sabd. Previous research on the shoulder ROM of youth volleyball players has not specifically tested SE and SF, making it difficult to perform a comparison. Previous research has indicated that a decrease in Sabd is associated with lower back pain [ 15 ]. Although no differences were found in these two parameters, they still fall within the scope of shoulder mobility and should be closely monitored. Overall, research on shoulder ROM and GIRD in youth volleyball players is relatively scarce. Our study found that youth volleyball players exhibit specific adaptations in their dominant hand, particularly in IR, ER, TROM, and Sadd. In addition, the prevalence of GIRD is notably high in this population. Future research should aim to conduct long-term follow-up studies on this group and span adolescent, young, and adult players to understand the shoulder ROM changes. Our study recommended that the youth volleyball players engage in eccentric exercises for posterior shoulder muscles and sleeper stretches that enhance shoulder mobility and strength. This study has several limitations that need to be addressed. One of the limitations of this study is that it only collected data from players who participated in the competition, excluding players who did not participate in the competition. These players who did not participate in the competition may have affected their performance due to injuries or insufficient shoulder mobility, so they were unable to participate in the competition. However, our study did not charge these players. Second, our participants come from four high schools. The variance in training schedules and volume among the teams could have led to different levels of muscle fatigue, influencing shoulder ROM measurements. Future research should consider tracking the training volume and schedules of players through different competition cycles to understand better the occurrence of specific shoulder ROM adaptations in young male volleyball players. Conclusions The results indicated that the ER and Sadd of the dominant arm in young male volleyball players were greater than those of the non-dominant arm, while IR and TROM were smaller, suggesting the presence of specific adaptations. The prevalence of GIRD was found to be 37.5%, accompanied by greater Sadd. Our study recommended that young volleyball players engage in eccentric exercises for posterior shoulder muscles and sleeper stretches that enhance shoulder mobility and strength. Therefore, it is necessary to conduct regular shoulder ROM screening for young male volleyball players and implement shoulder load management or preventative measures to avoid subsequent shoulder pain or injuries. Abbreviations ROM Range of motion GIRD Glenohumeral Internal Rotation Deficit TROM Total rotation range of motion SE Shoulder hyper-extension SF Shoulder flexion IR Internal rotation ER External rotation Sadd Horizontal adduction Sabd Horizontal abduction Declarations Acknowledgments: We are grateful to all participants for their assistance in this study This research received no external funding. Competing interests: The authors declare no conflicts of interest. Ethics approval: The study was approved by the Human Research Ethics Committee of Fu Jen Catholic University in Taiwan (IRB No: FJU-IRB C110139). Consent to participate: Informed consent was obtained from all subjects and their parents involved in the study after being fully informed of the procedures and purpose of the study. Consent for publication: The participant in the picture provided written informed consent that the picture can be published. Author contributions: K.Y.C. and H.Y.C contributed to the study design and drafted the manuscript. K.Y.C., W.L.W, and C.W.C contributed to data collection. K.Y.C., S.C.C. and H.Y.C made critical revisions to the manuscript. All authors approved the final version of the manuscript and agreed to be accountable for all aspects of the work. References Escamilla R, Fleisig G, Barrentine S, Andrews J, Moorman C 3 rd (2002). Kinematic and kinetic comparisons between American and Korean professional baseball pitchers. 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Arthroscopy 29(1):141-161.e26. doi:10.1016/j.arthro.2012.10.009 Kinsella SD, Thomas SJ, Huffman GR, Kelly JD 4 th (2014). The thrower's shoulder. Orthop Clin North Am 45(3):387-401. doi:10.1016/j.ocl.2014.04.003 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-5262561","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":366299778,"identity":"9f47d612-c5f9-49a8-b8fc-ad37955df4f4","order_by":0,"name":"Kun-Yu Chou","email":"","orcid":"","institution":"National Taiwan Sport University","correspondingAuthor":false,"prefix":"","firstName":"Kun-Yu","middleName":"","lastName":"Chou","suffix":""},{"id":366299780,"identity":"80a4615d-36ca-4ec1-8183-0df82dc654f7","order_by":1,"name":"Wan-Ling Wu","email":"","orcid":"","institution":"National Taiwan Normal University","correspondingAuthor":false,"prefix":"","firstName":"Wan-Ling","middleName":"","lastName":"Wu","suffix":""},{"id":366299782,"identity":"81a24935-c58d-4f82-bdcf-e938d0ae793e","order_by":2,"name":"Chun-Wen Chiu","email":"","orcid":"","institution":"National Taiwan Sport University","correspondingAuthor":false,"prefix":"","firstName":"Chun-Wen","middleName":"","lastName":"Chiu","suffix":""},{"id":366299783,"identity":"5f4b223a-3487-404c-aac5-80acd1adb2ef","order_by":3,"name":"Shih-Chung Cheng","email":"","orcid":"","institution":"National Taiwan Sport University","correspondingAuthor":false,"prefix":"","firstName":"Shih-Chung","middleName":"","lastName":"Cheng","suffix":""},{"id":366299785,"identity":"7e757625-9d5b-4241-83df-75ef3df86666","order_by":4,"name":"Hsiao-Yun Chang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA00lEQVRIiWNgGAWjYJCCAwk/JOSgbGaidDAeeNhjY8zABtPCRlgL88EHbGmJDURrMbiRe+BAAs/h9O3y7c8kGCqsExvkewwIaMlLOJBgcTh3ZxuPmQTDmXSgdTyEtOQYgGzJ3XCMh02Cse0wUAvvBiK0sB1ONzjG/kyC8R/xWtISDI4xmEkwNhChRfLMG4MDiT02hhuO5RhbJBxLN25jy/+AVwvf8Rzjjz9+SMgbHD7+8MaHGmvZfuZjCXi1KBxA5oHUEoxJ+QZCKkbBKBgFo2AUAACBXkqyzc0MxgAAAABJRU5ErkJggg==","orcid":"","institution":"National Taiwan Sport University","correspondingAuthor":true,"prefix":"","firstName":"Hsiao-Yun","middleName":"","lastName":"Chang","suffix":""}],"badges":[],"createdAt":"2024-10-14 16:10:13","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5262561/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5262561/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":66845923,"identity":"e9d2ff51-4195-4e87-b527-ddec17faff1e","added_by":"auto","created_at":"2024-10-17 06:06:39","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":108666,"visible":true,"origin":"","legend":"\u003cp\u003eShoulder range of motion measurement. (a) Shoulder hyperextension; (b)Shoulder flexion; (c) Shoulder internal rotation; (d) Shoulder external rotation; (e) Shoulder horizontal adduction; (f) Shoulder horizontal abduction.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-5262561/v1/3f15c9fdeee46189ccb5ba37.png"},{"id":69326931,"identity":"6cecb500-a303-4b9b-8043-6e7efb3dd3b7","added_by":"auto","created_at":"2024-11-19 08:09:40","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":608479,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5262561/v1/8957618d-9754-47a8-a22e-ca17d1c61bc0.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Adapted Characteristic in the Range of Motion of the Shoulder for Young Male Volleyball Players","fulltext":[{"header":"Introduction","content":"\u003cp\u003eVolleyball is an overhead sport with high-frequency usage of spiking and serving movements. The volleyball players are expected to maximize the external rotation angle of shoulder to prolong the acceleration distance of their spikes or serves for higher speed and power [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. During an attack, the arm swing speed of volleyball players may reach 100 km/h [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. In such a movement pattern, the key factor of maintaining the glenohumeral head stabilizer inside the joint fossa heavily relies on the surrounding soft tissues and muscles in charge of movement control [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe fast arm swing speed and the frequent repetition of spiking and serving movements make volleyball players prone to shoulder injuries [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. However, most re-search on sports injuries in volleyball players focused on the knee and ankle, while the shoulder received relatively less attention. Kyle et al. reported that shoulder injuries account for 12.2% of volleyball-related injuries [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]; another study indicated that the prevalence of shoulder injuries among volleyball players was up to 24% [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. These findings have shown us the significant risk of shoulder injuries among volleyball players, which is a non-negligible issue. Additionally, the musculoskeletal system of adolescents is still in the growing phase, and the development of the upper limb musculoskeletal system is usually completed around 22\u0026ndash;25 years of age [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. The extensive training involving overhead movements can further increase the risk of shoulder injuries. Previous research has shown that high-intensity training in adolescent athletes may lead to abnormalities in shoulder mobility, skeletal growth, and muscles/tendons pathological changes in the upper limbs. These abnormalities can result in shoulder tendinitis, scapular dyskinesis, and lower back pain [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Frisch et al. found that 40% of high school female volleyball players experienced non-traumatic shoulder pain, but only 33% took rest [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. However, there is limited research on the risk factors related to shoulder injuries in adolescent volleyball players\u0026rsquo; intrinsic factors, such as joint mobility and muscle strength. It is critical to address the issue of shoulder injuries and the associated risk factors in this population.\u003c/p\u003e \u003cp\u003eGlenohumeral internal rotation deficiency (GIRD) is one of the risk factors for shoulder injuries [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. GIRD occurs in overhead athletes due to the eccentric con-traction of soft tissues in the posterior shoulder during the deceleration phase of the arm swing, leading to microtrauma and subsequent tightness of these tissues [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The study by Mizoguchi et al. showed that 38% of young volleyball players experienced a reduction in the internal rotation range of motion (ROM) and total rotation range of motion (TROM) of the dominant shoulder [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Previous studies have indicated that posterior shoulder tightness may lead to a decrease in shoulder horizontal adduction and internal rotation ROM, as well as an increase in external rotation ROM, which may all be contributing to the development of GIRD [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Manske et al. differentiated GIRD into two categories: normal GIRD, commonly seen in overhead athletes, described as a reduction in internal rotation less than 18 degrees, and a symmetrical bilateral TROM reduction; the other is pathological GIRD, characterized by a reduction in internal rotation greater than 18 degrees and a reduction in dominant shoulder TROM greater than 5 degrees [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. They also noted that reduced TROM and external rotation might increase the risk of shoulder injuries. Schmalzl et al. found that in adult volleyball players, GIRD of less than 10 degrees was significantly associated with shoulder impingement and decreased TROM [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Alqarni et al. reported that players with a history of shoulder pain had larger ROM differences in GIRD and TROM than those without a history of shoulder pain [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. These findings suggest that a reduction in TROM often accompanies GIRD and is significantly correlated with shoulder pain. Hence, understanding these adaptive changes is of utmost importance for preventing and treating shoulder injuries in adolescent volleyball players. Therefore, the purpose of this study was to assess the bilateral shoulder in high school male volleyball athletes.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Design and Participate\u003c/h2\u003e \u003cp\u003eThis study is a prospective cross-sectional study. During the preseason phase of the 2023 season, data on bilateral shoulders were collected from volleyball players. The subjects in this study were players from the top four teams in the ranking of the Taiwan High School Volleyball League (HVL).\u003c/p\u003e \u003cp\u003eA total of 40 high school male volleyball athletes participated in the study. Among the participants, 34 were right-handed and 6 were left-handed. The participants' average age was 17.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.93 years, average height was 180.0\u0026thinsp;\u0026plusmn;\u0026thinsp;5.91 cm, average weight was 71.1\u0026thinsp;\u0026plusmn;\u0026thinsp;7.47 kg, and average volleyball experience was 6.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.56 years. Inclusion criteria were: no history of upper limb injury, fracture, dislocation, subluxation, or any neurological disorders in the past year; negative results on special shoulder tests administered by a physical therapist; and a minimum training load of four days per week in addition to at least three years of specialized training in volleyball. All participants were informed about the experimental procedures, and both participants and their parents signed the informed consent forms. The study protocol adhered to the Declaration of Helsinki and was approved by the Human Research Ethics Committee of Fu Jen Catholic University in Taiwan (IRB No: FJU-IRB C110139).\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eProcedure\u003c/h3\u003e\n\u003cp\u003eThis study was conducted with an iPhone 12 Pro Max (Apple Inc., Cupertino, CA), recording videos (1080 HD/60 fps) of the active ROM of the shoulder. The videos were then analyzed using Kinovea software (Version 0.9.5; Kinovea open source project, \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ewww.kinovea.org\u003c/span\u003e\u003c/span\u003e) to measure the ROM. The shoulder ROM tests included measurements of shoulder hyper-extension (SE), shoulder flexion (SF), internal rotation (IR), external rotation (ER), horizontal adduction (Sadd), and horizontal abduction (Sabd) (Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). All measurements underwent test-retest reliability assessments before the formal pilot testing, with reliability coefficients ranging from 0.984 to 0.998 (SE: 0.984, SF: 0.993, IR: 0.997, ER: 0.991, TROM: 0.993, Sadd: 0.998, and Sabd: 0.995). Both the dominant and non-dominant sides were tested randomly. In this study, the dominant hand was defined as the upper limb used by the volleyball player for attacking movements. All measurements and data collection were performed by one researcher; each measuring item was tested twice and the average value was used for further statistical analysis. All tests were conducted indoors gym. Participants performed a 15-minute warm-up, including jogging and stretching. After warming up, participants drew lots to determine the order of testing and then had their shoulder ROM measured in sequence. There was a 5-minute rest period between each measurement item.\u003c/p\u003e\n\u003cp\u003eShoulder Hyper-Extension Measurement (Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003ea): The participant lay supine on a platform with the arm positioned alongside the body. The researcher manually stabilized the scapula. The participant then moved the arm posteriorly to its limit. Upon reaching the maximal extension, the video recording was stopped. The video was then analyzed using Kinovea to measure the joint angle. The shoulder joint center was used as the axis to draw two straight lines: one parallel to the lateral midline of the trunk and the other parallel to the midline of the humerus. The angle between these two lines was recorded as the shoulder hyper-extension angle [\u003cspan class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e\n\u003cp\u003eShoulder Flexion Measurement (Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003eb): The participant lay supine on a platform with the arm positioned alongside the body. The researcher manually stabilized the scapula. The participant then raised the arm overhead into flexion to the maximal possible degree. Upon reaching maximal flexion, the video recording was stopped. The video was then analyzed using Kinovea to measure the joint angle. The shoulder joint center was used as the axis to draw two lines: one parallel to the lateral midline of the trunk and the other parallel to the midline of the humerus. The angle between these two lines was recorded as the shoulder flexion angle [\u003cspan class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e\n\u003cp\u003eShoulder Internal/External Rotation Measurement (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003ec \u0026amp; d): The participant lay supine on a platform with the shoulder abducted to 90 degrees, the elbow flexed to 90 degrees, and the forearm positioned with the palm facing down. For in-ternal rotation, the participant moved the arm towards the feet till the end range. Up-on reaching maximal internal rotation, the video recording was stopped. The video was then analyzed using Kinovea to measure the joint angle. Olecranon was used as the axis, two lines were drawn: one perpendicular to the ground and the other parallel to the longitudinal axis of the ulna. The angle between these two lines was recorded as the shoulder internal rotation angle [\u003cspan class=\"CitationRef\"\u003e20\u003c/span\u003e]. For external rotation, the participant\u0026apos;s fore-arm was again positioned with the palm facing down, and the participant moved the arm towards the head to the maximal limit. Upon reaching maximal external rotation, the video recording was stopped. The video was then analyzed using Kinovea to measure the joint angle. Using the olecranon as the axis, two lines were drawn: one perpendicular to the ground and the other parallel to the longitudinal axis of the ulna. The angle between these two lines was recorded as the shoulder external rotation angle [\u003cspan class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e\n\u003cp\u003eShoulder Horizontal Adduction Measurement (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003ed): The participant lay supine on a platform while the researcher manually stabilized the scapula. The participant then moved the arm horizontally across the chest towards the opposite shoulder to the maximal limit. Upon reaching maximal horizontal adduction, the video recording was stopped. The video was then analyzed using Kinovea to measure the joint angle. Using the acromion as the axis, two straight lines were drawn: one parallel to the top of the shoulder and the other parallel to the longitudinal axis of the humerus. The angle between these two lines was recorded as the shoulder horizontal adduction angle [\u003cspan class=\"CitationRef\"\u003e21\u003c/span\u003e]. This measurement assesses the flexibility of the posterior shoulder; a larger angle indicates greater tightness in the posterior shoulder.\u003c/p\u003e\n\u003cp\u003eShoulder Horizontal Abduction Measurement (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003ee): The participant lay supine on a platform with the shoulder abducted to 90 degrees. The participant then moved the arm horizontally and posteriorly to the maximal limit. Upon reaching maximal horizontal abduction, the video recording was stopped. The video was then analyzed using Kinovea to measure the joint angle. Using the acromion as the axis, two straight lines were drawn: one parallel to the top of the shoulder and the other parallel to the longitudinal axis of the humerus. The angle between these two lines was recorded as the shoulder horizontal abduction angle [\u003cspan class=\"CitationRef\"\u003e21\u003c/span\u003e]. This measurement assesses the flexibility of the anterior shoulder, specifically the pectoralis muscle; a larger angle indicates greater anterior shoulder flexibility.\u003c/p\u003e\n\u003cp\u003eAfter completing the measurements, the total rotational range of motion (TROM) and glenohumeral internal rotation deficit (GIRD) were calculated using the participants\u0026apos; shoulder internal and external rotation data. The formula for TROM is as follows:\u003c/p\u003e\n\u003cp\u003eTROM\u0026thinsp;=\u0026thinsp;Shoulder Internal Rotation (IR)\u0026thinsp;+\u0026thinsp;Shoulder External Rotation (ER)\u003c/p\u003e\n\u003cp\u003eThe GIRD was determined using the following criteria: if the difference between the non-dominant side\u0026apos;s internal rotation and the dominant side\u0026apos;s internal rotation was greater than 10 degrees, and the difference between the non-dominant side\u0026apos;s TROM and the dominant side\u0026apos;s TROM was greater than 5 degrees, the participant was classified as having GIRD [\u003cspan class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e\n\u003cp\u003e~~~~~~Please insert Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e here~~~~\u003c/p\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\n \u003ch2\u003eStatistical Analysis\u003c/h2\u003e\n \u003cp\u003eThe data was analyzed using SPSS 20.0 for Windows (IBM Corp., Armonk, NY). Descriptive statistics, including mean and standard deviation (SD), were presented. The Shapiro-Wilk test was conducted to assess the normality of the data. If both groups exhibited a normal distribution, a paired-sample t-test was used to compare the differences in shoulder ROM between the dominant and non-dominant sides of the participants; if exhibited otherwise, the Wilcoxon signed-rank test was employed for the analysis. Finally, Cohen\u0026rsquo;s d was calculated to determine the effect size, with 0.2 indicating a small effect, 0.5 a medium effect, and 0.8 a large effect. The significance level (\u0026alpha;) was set at 0.05.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eThis study compared the shoulder ROM between the dominant and non-dominant sides of high school male volleyball players, with the results shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The findings indicated that IR on the dominant side was significantly less than on the non-dominant side by 9.97\u0026thinsp;\u0026plusmn;\u0026thinsp;10.25 degrees (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.000, Cohen's \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.92). The TROM on the dominant side was significantly less than on the non-dominant side by 4.85\u0026thinsp;\u0026plusmn;\u0026thinsp;12.72 degrees (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.021, Cohen's \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.37). ER on the dominant side was significantly greater than on the non-dominant side by 5.13\u0026thinsp;\u0026plusmn;\u0026thinsp;9.1 degrees (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.001, Cohen's \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.57). Sadd on the dominant side was significantly greater than on the non-dominant side by 5.27\u0026thinsp;\u0026plusmn;\u0026thinsp;6.50 degrees (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.000, Cohen's \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.69). The other parameters failed to reach statistical significance, including SE (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.106, Cohen's \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.24), SF (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.368, Cohen's \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.07), and Sabd (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.417, Cohen's \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.08).\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\u003eShoulder range of motion results\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\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eROM\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDominant Side\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNon-dominant Side\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eDifference between the bilateral side\u003csup\u003e#\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eCohen\u0026rsquo;s \u003cem\u003ed\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSE\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e51.43\u0026thinsp;\u0026plusmn;\u0026thinsp;4.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e52.74\u0026thinsp;\u0026plusmn;\u0026thinsp;6.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-1.31\u0026thinsp;\u0026plusmn;\u0026thinsp;5.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.106\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.24\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e177.55\u0026thinsp;\u0026plusmn;\u0026thinsp;9.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e178.17\u0026thinsp;\u0026plusmn;\u0026thinsp;8.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-0.62\u0026thinsp;\u0026plusmn;\u0026thinsp;4.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.368\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.07\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42.17\u0026thinsp;\u0026plusmn;\u0026thinsp;11.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e52.14\u0026thinsp;\u0026plusmn;\u0026thinsp;10.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-9.97\u0026thinsp;\u0026plusmn;\u0026thinsp;10.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.000*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.92\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eER\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e94.96\u0026thinsp;\u0026plusmn;\u0026thinsp;10.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e89.83\u0026thinsp;\u0026plusmn;\u0026thinsp;7.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.13\u0026thinsp;\u0026plusmn;\u0026thinsp;9.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.001*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.57\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTROM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e137.11\u0026thinsp;\u0026plusmn;\u0026thinsp;13.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e141.96\u0026thinsp;\u0026plusmn;\u0026thinsp;13.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-4.85\u0026thinsp;\u0026plusmn;\u0026thinsp;12.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.021*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.37\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSadd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e44.87\u0026thinsp;\u0026plusmn;\u0026thinsp;8.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e39.60\u0026thinsp;\u0026plusmn;\u0026thinsp;7.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.27\u0026thinsp;\u0026plusmn;\u0026thinsp;6.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.000*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.69\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSabd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e216.46\u0026thinsp;\u0026plusmn;\u0026thinsp;10.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e215.52\u0026thinsp;\u0026plusmn;\u0026thinsp;11.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.94\u0026thinsp;\u0026plusmn;\u0026thinsp;7.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.417\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003eNote: Unit: degree; SE: Shoulder Hyper-Extension; SF: Shoulder Flexion; IR: Internal Rotation; ER: External rotation; TROM: Total Rotational Range of Motion; Sadd: Shoulder Horizontal Adduction; Sabd: Shoulder Horizontal Abduction; *\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05; Cohen\u0026rsquo;s d\u0026thinsp;\u0026le;\u0026thinsp;2 means low effects, 2\u0026thinsp;\u0026lt;\u0026thinsp;Cohen\u0026rsquo;s \u003cem\u003ed\u003c/em\u003e\u0026thinsp;\u0026le;\u0026thinsp;5 means mild effects, Cohen\u0026rsquo;s \u003cem\u003ed\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;5 means high effects; \u003csup\u003e#\u003c/sup\u003eDifference between the bilateral side means ROM of Dominant Side minus Non-dominant Side.\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\u003eAmong the 40 participants, 15 met the criteria for GIRD, indicating that 37.5% of the subjects had GIRD. The shoulder ROM performance of those with GIRD is shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. For the GIRD group, IR and TROM on the dominant side were significantly less than on the non-dominant side, IR was less by 18.68\u0026thinsp;\u0026plusmn;\u0026thinsp;7.23 degrees (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.000, Cohen's \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.72), and TROM was less by 17.32\u0026thinsp;\u0026plusmn;\u0026thinsp;10.25 degrees (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.000, Cohen's \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.37). Additionally, Sadd on the dominant side was significantly greater by 6.71\u0026thinsp;\u0026plusmn;\u0026thinsp;6.87 degrees (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.002, Cohen's \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.88). The other parameters did not reach statistical significance, including SE (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.817, Cohen's \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.07), SF (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.245, Cohen's \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.17), ER (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.543, Cohen's \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.15), and Sabd (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.656, Cohen's \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.05).\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\u003eGIRD athletes\u0026rsquo; shoulder range of motion results\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" morerows=\"1\" nameend=\"c2\" namest=\"c1\" rowspan=\"2\"\u003e \u003cp\u003eROM\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eNon-GIRD\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c9\" namest=\"c7\"\u003e \u003cp\u003eGIRD\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCohen\u0026rsquo;s \u003cem\u003ed\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eCohen\u0026rsquo;s \u003cem\u003ed\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSE\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDominant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e52.25\u0026thinsp;\u0026plusmn;\u0026thinsp;4.75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.035*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e50.05\u0026thinsp;\u0026plusmn;\u0026thinsp;4.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e.817\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.07\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-dominant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e54.13\u0026thinsp;\u0026plusmn;\u0026thinsp;5.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e50.43\u0026thinsp;\u0026plusmn;\u0026thinsp;7.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDominant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e177.11\u0026thinsp;\u0026plusmn;\u0026thinsp;9.53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.726\u003csup\u003e\u003cb\u003e\u0026sect;\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e178.29\u0026thinsp;\u0026plusmn;\u0026thinsp;8.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e.245\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-dominant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e177.25\u0026thinsp;\u0026plusmn;\u0026thinsp;7.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e179.71\u0026thinsp;\u0026plusmn;\u0026thinsp;8.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eIR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDominant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e44.69\u0026thinsp;\u0026plusmn;\u0026thinsp;10.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.007*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e37.95\u0026thinsp;\u0026plusmn;\u0026thinsp;10.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e.000*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1.72\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-dominant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e49.45\u0026thinsp;\u0026plusmn;\u0026thinsp;9.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e56.63\u0026thinsp;\u0026plusmn;\u0026thinsp;10.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eER\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDominant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e96.21\u0026thinsp;\u0026plusmn;\u0026thinsp;9.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.000*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e92.87\u0026thinsp;\u0026plusmn;\u0026thinsp;10.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e.543\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.15\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-dominant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e88.83\u0026thinsp;\u0026plusmn;\u0026thinsp;8.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e91.51\u0026thinsp;\u0026plusmn;\u0026thinsp;7.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTROM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDominant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e140.88\u0026thinsp;\u0026plusmn;\u0026thinsp;11.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.056\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e130.81\u0026thinsp;\u0026plusmn;\u0026thinsp;13.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e.000*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1.37\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-dominant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e138.26\u0026thinsp;\u0026plusmn;\u0026thinsp;12.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e148.13\u0026thinsp;\u0026plusmn;\u0026thinsp;12.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSadd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDominant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e43.30\u0026thinsp;\u0026plusmn;\u0026thinsp;8.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.002*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e47.49\u0026thinsp;\u0026plusmn;\u0026thinsp;7.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e.002*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.88\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-dominant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e38.90\u0026thinsp;\u0026plusmn;\u0026thinsp;7.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e40.78\u0026thinsp;\u0026plusmn;\u0026thinsp;7.61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSabd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDominant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e218.80\u0026thinsp;\u0026plusmn;\u0026thinsp;8.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e.257\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e212.71\u0026thinsp;\u0026plusmn;\u0026thinsp;11.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e.656\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNon-dominant\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e216.89\u0026thinsp;\u0026plusmn;\u0026thinsp;10.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e213.33\u0026thinsp;\u0026plusmn;\u0026thinsp;13.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"9\" nameend=\"c9\" namest=\"c1\"\u003e \u003cp\u003eNote: Unit: degree; GIRD: glenohumeral internal rotation deficit; SE: Shoulder Hyper-Extension; SF: Shoulder Flexion; IR: Internal Rotation; ER: External rotation; TROM: Total Rotational Range of Motion; Sadd: Shoulder Horizontal Adduction; Sabd: Shoulder Horizontal Abduction; * \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05; Cohen\u0026rsquo;s d\u0026thinsp;\u0026le;\u0026thinsp;2 means low effects; 2\u0026thinsp;\u0026lt;\u0026thinsp;Cohen\u0026rsquo;s \u003cem\u003ed\u003c/em\u003e\u0026thinsp;\u0026le;\u0026thinsp;5 means mild effects; Cohen\u0026rsquo;s \u003cem\u003ed\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;5 means high effects;\u003csup\u003e\u0026sect;\u003c/sup\u003e This parameter was using Wilcoxon signed-rank test to analyzed.\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~~~~~~Please insert Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e here~~~~\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study aimed to evaluate the shoulder ROM in high school male volleyball players. The results showed that the dominant side had significantly less internal rotation and total rotational ROM than the non-dominant side, while the dominant side had significantly greater external rotation and shoulder horizontal adduction. Previous research indicated that overhead athletes often develop posterior shoulder tightness due to long-term overhead arm movements, leading to increased Sadd and decreased IR [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], which is consistent with our findings. These results might be due to shoulder adaptations caused by overuse, resulting in posterior shoulder tightness. Past research on volleyball players has paid little attention to Sadd and posterior shoulder tightness. However, our study observed that the Sadd of the dominant hand in high school male volleyball players was significantly greater than that of the non-dominant arm. Vad et al. found a high correlation between reduced IR and shoulder injuries and pain [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. That means greater Sadd ROM and posterior shoulder tightness may be the risk factors of shoulder injury for youth volleyball players. To prevent such conditions, stretching exercises targeting the posterior shoulder muscles for youth volleyball players to maintain appropriate shoulder ROM.\u003c/p\u003e \u003cp\u003eThe results of this study found that the dominant side of our participants exhibited significant decreases in internal rotation (IR) and increases in external rotation (ER), similar to findings in previous studies on adolescent volleyball players [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Additionally, research by Schmalzl et al. on handball and volleyball players reported similar results [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Previous studies have also indicated that overhead athletes often experience decreased IR, accompanied by increased ER and reduced total rotational range of motion (TROM) [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e], which aligns with our findings. However, Mizoguchi et al. found that adolescent volleyball players had significantly increased ER and decreased IR, but no significant difference in TROM, partially aligning with our results [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. In volleyball, players ought to achieve maximum external rotation of the shoulder to enhance the power and speed of their attacks and serve [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Repeated volleyball attacks and serve would lead to increased ER. It may also cause pathological changes in the shoulder. This condition can be managed by sleeper stretch and strengthening the shoulder external rotators, especially the eccentric muscles, as a preventive strategy to reduce the risk of shoulder injuries [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThis study further investigated the incidence of GIRD among youth volleyball players, finding it to be 37.5%. Previous studies on adolescent volleyball players have reported GIRD incidence rates of 38.2% [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e] and 38.5% [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], which are similar to our findings. Additionally, Schmalzl et al. reported an even higher incidence rate of 72% in male adult handball and volleyball players [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Past research has indicated that volleyball players with GIRD often experience increased ER and decreased TROM [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e], which conforms with our results. However, Mizoguchi et al. found that adolescent volleyball players with GIRD exhibited significant decreases in both ER and TROM, partially matching up with our findings [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Previous studies have suggested that increased ER in the dominant hand is a specific adaptation in overhead athletes, allowing for better athletic performance [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. The difference between adult and adolescent players may come from the accumulation of tissue micro-damage caused by long-term training and repeated overhead movements in adults. Research has indicated that athletes with GIRD who continue to train may experience shoulder pain and an increased risk of injury [\u003cspan additionalcitationids=\"CR27\" citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e], leading to absence from practices and competitions. However, this situation has also been found in the youth players in this study. This means that changes and adaptations in shoulder ROM need to be monitored starting with youth players.\u003c/p\u003e \u003cp\u003eThis study did not find significant differences in the SE, SF, and Sabd. Previous research on the shoulder ROM of youth volleyball players has not specifically tested SE and SF, making it difficult to perform a comparison. Previous research has indicated that a decrease in Sabd is associated with lower back pain [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Although no differences were found in these two parameters, they still fall within the scope of shoulder mobility and should be closely monitored.\u003c/p\u003e \u003cp\u003eOverall, research on shoulder ROM and GIRD in youth volleyball players is relatively scarce. Our study found that youth volleyball players exhibit specific adaptations in their dominant hand, particularly in IR, ER, TROM, and Sadd. In addition, the prevalence of GIRD is notably high in this population. Future research should aim to conduct long-term follow-up studies on this group and span adolescent, young, and adult players to understand the shoulder ROM changes. Our study recommended that the youth volleyball players engage in eccentric exercises for posterior shoulder muscles and sleeper stretches that enhance shoulder mobility and strength.\u003c/p\u003e \u003cp\u003eThis study has several limitations that need to be addressed. One of the limitations of this study is that it only collected data from players who participated in the competition, excluding players who did not participate in the competition. These players who did not participate in the competition may have affected their performance due to injuries or insufficient shoulder mobility, so they were unable to participate in the competition. However, our study did not charge these players. Second, our participants come from four high schools. The variance in training schedules and volume among the teams could have led to different levels of muscle fatigue, influencing shoulder ROM measurements. Future research should consider tracking the training volume and schedules of players through different competition cycles to understand better the occurrence of specific shoulder ROM adaptations in young male volleyball players.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe results indicated that the ER and Sadd of the dominant arm in young male volleyball players were greater than those of the non-dominant arm, while IR and TROM were smaller, suggesting the presence of specific adaptations. The prevalence of GIRD was found to be 37.5%, accompanied by greater Sadd. Our study recommended that young volleyball players engage in eccentric exercises for posterior shoulder muscles and sleeper stretches that enhance shoulder mobility and strength. Therefore, it is necessary to conduct regular shoulder ROM screening for young male volleyball players and implement shoulder load management or preventative measures to avoid subsequent shoulder pain or injuries.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 32.5123%;\"\u003e\n \u003cp\u003eROM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67.4877%;\"\u003e\n \u003cp\u003eRange of motion\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 32.5123%;\"\u003e\n \u003cp\u003eGIRD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67.4877%;\"\u003e\n \u003cp\u003eGlenohumeral Internal Rotation Deficit\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 32.5123%;\"\u003e\n \u003cp\u003eTROM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67.4877%;\"\u003e\n \u003cp\u003eTotal rotation range of motion\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 32.5123%;\"\u003e\n \u003cp\u003eSE\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67.4877%;\"\u003e\n \u003cp\u003eShoulder hyper-extension\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 32.5123%;\"\u003e\n \u003cp\u003eSF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67.4877%;\"\u003e\n \u003cp\u003eShoulder flexion\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 32.5123%;\"\u003e\n \u003cp\u003eIR\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67.4877%;\"\u003e\n \u003cp\u003eInternal rotation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 32.5123%;\"\u003e\n \u003cp\u003eER\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67.4877%;\"\u003e\n \u003cp\u003eExternal rotation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 32.5123%;\"\u003e\n \u003cp\u003eSadd\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67.4877%;\"\u003e\n \u003cp\u003eHorizontal adduction\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 32.5123%;\"\u003e\n \u003cp\u003eSabd\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67.4877%;\"\u003e\n \u003cp\u003eHorizontal abduction\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments:\u003c/strong\u003e We are grateful to all participants for their assistance in this study\u003c/p\u003e\n\u003cp\u003eThis research received no external funding.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u003c/strong\u003e The authors declare no conflicts of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval:\u003c/strong\u003e The study was approved by the Human Research Ethics Committee of Fu Jen Catholic University in Taiwan (IRB No: FJU-IRB C110139).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate:\u0026nbsp;\u003c/strong\u003eInformed consent was obtained from all subjects and their parents involved in the study after being fully informed of the procedures and purpose of the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u003c/strong\u003e The participant in the picture provided written informed consent that the picture can be published.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions:\u0026nbsp;\u003c/strong\u003eK.Y.C. and H.Y.C contributed to the study design and drafted the manuscript. K.Y.C., W.L.W, and C.W.C contributed to data collection. K.Y.C., S.C.C. and H.Y.C made critical revisions to the manuscript. All authors approved the final version of the manuscript and agreed to be accountable for all aspects of the work.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eEscamilla R, Fleisig G, Barrentine S, Andrews J, Moorman C 3\u003csup\u003erd \u003c/sup\u003e(2002). Kinematic and kinetic comparisons between American and Korean professional baseball pitchers. Sports Biomech 1(2):213-228. doi:10.1080/14763140208522798\u003c/li\u003e\n\u003cli\u003eForthomme B, Croisier JL, Ciccarone G, Crielaard JM, Cloes M (2005). Factors correlated with volleyball spike velocity. Am J Sports Med 33(10):1513-1519. doi:10.1177/0363546505274935\u003c/li\u003e\n\u003cli\u003eStickley CD, Hetzler RK, Freemyer BG, Kimura IF (2008). Isokinetic peak torque ratios and shoulder injury history in adolescent female volleyball athletes. 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Br J Sports Med 48(17):1327-1333. doi:10.1136/bjsports-2014-093702\u003c/li\u003e\n\u003cli\u003eMizoguchi Y, Suzuki K, Shimada N, Naka H, Kimura F, Akasaka K (2022). Prevalence of glenohumeral internal rotation deficit and sex differences in range of motion of adolescent volleyball players: A case-control study. Healthcare (Basel) 10(11):2263. Published 2022 Nov 11. doi:10.3390/healthcare10112263\u003c/li\u003e\n\u003cli\u003eKibler WB, Kuhn JE, Wilk K, Sciascia A, Moore S, Laudner K, Ellenbecker T, Thigpen C, Uhl T (2013). The disabled throwing shoulder: spectrum of pathology-10-year update. Arthroscopy 29(1):141-161.e26. doi:10.1016/j.arthro.2012.10.009\u003c/li\u003e\n\u003cli\u003eKinsella SD, Thomas SJ, Huffman GR, Kelly JD 4\u003csup\u003eth\u003c/sup\u003e (2014). The thrower\u0026apos;s shoulder. Orthop Clin North Am 45(3):387-401. doi:10.1016/j.ocl.2014.04.003\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Overhead sports, Flexibility, Shoulder injury, Glenohumeral Internal Rotation Deficit","lastPublishedDoi":"10.21203/rs.3.rs-5262561/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5262561/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eVolleyball players often repeatedly perform spiking and serving, which may lead to muscle microtrauma of the shoulder and consequently reduce shoulder joint range of motion (ROM) and increase the risk of shoulder injuries.\u003c/p\u003e\u003ch2\u003eAims\u003c/h2\u003e \u003cp\u003eThis study aimed to understand and evaluate the bilateral shoulder ROM in high school male volleyball athletes to discover the adapted characteristics.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eForty high school male volleyball athletes participated in this study. The shoulder ROM measurements were taken for both the dominant and non-dominant sides. The paired samples t-tests were used to analyze shoulder ROM differences between the dominant and non-dominant sides.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe dominant side showed a significantly lower in internal rotation (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.000) and total shoulder rotation ROM (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.021) compared to the non-dominant side (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05). Conversely, the dominant side of the shoulder exhibited significantly greater external rotation (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.001) and shoulder horizontal adduction (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.000) than the non-dominant side (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05). No significant differences were found in other measured parameters. The incidence of Glenohumeral Internal Rotation Deficit (GIRD) among all subjects was 37.5%.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eHigh school male volleyball athletes in this study exhibited tightness in the posterior shoulder of their dominant side, indicating specific adaptations in shoulder ROM and a considerable prevalence of GIRD, observed in approximately one-quarter of the athletes. It is recommended to incorporate stretching and eccentric muscle training focusing on the posterior shoulder to mitigate these adaptations and reduce the risk of shoulder injuries.\u003c/p\u003e","manuscriptTitle":"The Adapted Characteristic in the Range of Motion of the Shoulder for Young Male Volleyball Players","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-10-17 06:06:34","doi":"10.21203/rs.3.rs-5262561/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a8fcc067-a15e-4764-ae9c-ad50bc9700dd","owner":[],"postedDate":"October 17th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-11-19T08:09:28+00:00","versionOfRecord":[],"versionCreatedAt":"2024-10-17 06:06:34","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5262561","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5262561","identity":"rs-5262561","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}