Comparison of upper body posture, shoulder range of motion of volleyball players with and without scapular dyskinesia

Comparison of upper body posture, shoulder range of motion of volleyball players with and without scapular dyskinesia | 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 Comparison of upper body posture, shoulder range of motion of volleyball players with and without scapular dyskinesia Fazel Pashaie, Sajad Roshani, Hamed Mahmoudi This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3969637/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 Repetitive movement patterns and continuous use of the upper limb in volleyball cause scapular movement disorders. The aim of the present study was to compare upper body posture, shoulder range of motion of volleyball players with and without scapular dyskinesia. Methods 50 volleyball players (25 volleyball players with scapular dyskinesia and 25 healthy volleyball players) were selected in a targeted manner from volleyball clubs in Urmia city. Head and shoulder posture were evaluated using photography. The thoracic spine was assessed by a flexible ruler; internal and external rotation of the shoulder using a goniometer. In order to compare the means of the two groups, independent t-test was used. Results The results showed a significant difference in forward head (P = 0.047), forward shoulder (P = 0.007) and thoracic spine posture (P = 0.037), and shoulder external rotation (P = 0.001) between healthy volleyball players and volleyball players with scapular dyskinesia. However, there was no significant difference in internal rotation of the shoulder (P = 0.148) between the two groups. Conclusion shoulder girdle posture of volleyball players with scapular dyskinesia seems to be poorer than that of volleyball players without scapular dyskinesia. Players with scapular dyskinesia had limited external rotation range compared to the healthy group. This issue may be affected by the position of the shoulder, which itself can be caused by a poor posture. scapular dyskinesia range of motion volleyball player posture Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Volleyball is considered one of the most popular sports and at the same time with a high risk of injury. Some volleyball skills require the engagement of the shoulder girdle while the upper limb is positioned overhead ( 1 ). Repetitive overhead movements cause disorders in the shoulder girdle movement, scapulohumeral rhythm, and injury to the shoulder joint ( 2 ). Scapular dyskinesia may be associated with symptoms such as muscle imbalance and limited shoulder range of motion, asymmetric posture, winged scapula, and shoulder instability. Scapular dyskinesia usually occurs due to muscle imbalance of the scapular stabilizers. If the scapular stabilizers do not work properly, the movements of the scapula will also be affected, and this problem will cause more stress on the shoulder joint capsule and cause injury ( 3 ). The position of the scapula determines the position of the glenoid fossa and the head of the humerus relative to the acromion. Therefore, the size of the space under the acromion and related injuries depends on the position of the scapula ( 4 ). Scapular Protraction which occurs as a result of muscle imbalance caused by repeated movements, can cause forward shoulder deformity. With this deformity, due to the change in the position of the scapula, the shoulder joint range of motion and the scapulohumeral rhythm can be affected ( 5 ). Also, forward shoulder posture leads to anterior tilt and incomplete upward rotation of the scapula during overhead movements and ultimately causes pain in the shoulder area ( 6 ). On the other hand, an increase in thoracic kyphosis can cause scapular Protraction and a decrease in the range of motion of the glenohumeral joint ( 7 ). Studies that investigated shoulder range of motion and performance of athletes with scapular dyskinesia have reported different results. Klarsen et al. reported a decrease in shoulder external rotation range of motion in subjects with scapular dyskinesia ( 8 ). Impairments in movement patterns, range of motion limitation and shoulder deformities can lead to poor skills and athlete's performance ( 9 ). But Amasai et al. studying the relationship between scapular dyskinesia and upper limb functional test, observed that people with scapular dyskinesia had higher score than healthy people ( 10 ). On the other hand, the results of Manukas et al.'s research showed that there is no significant difference between the performance score of people with and without scapular dyskinesia ( 11 ). In addition, we found no studies that investigated the posture of athletes with scapular dyskinesia. Therefore, the purpose of this study is to compare upper body posture, shoulder range of motion of volleyball players with and without scapular dyskinesia. Methods This study has been approved under the supervision of Urmia University Ethics Committee. The statistical population included all volleyball players from Urmia who were playing professionally at the national league. 25 healthy volleyball players were selected randomly and 25 volleyball players with scapular dyskinesia were selected purposefully as the statistical sample. Entry criteria included male volleyball players participating in national league, having general health, normal body mass index, no history of fractures and dislocations in the shoulder girdle joints, and a positive scapular dyskinesia test for the scapular dyskinesia group. Exclusion criteria included presence of pain in the shoulder joint during range of motion and refusal to continue cooperation in the research process. After fully explaining the research process to participants, those who agreed to take part in our study signed a written informed consent. All evaluations for each subject were performed in one session of approximately 30 minutes. Scapular dyskinesia measurement Observational dyskinesis test (SDT) described by McClure et al. was used to diagnose scapular dyskinesia(Fig. 1 ). In this test, participants were asked to remove their shirts during the study to allow observation of the posterior thorax and scapula, and they were asked to perform five repetitions of bilateral active shoulder flexion and five repetitions of bilateral shoulder abduction. Dumbbell weighted test movements were performed according to body weight (2.5 kg for those weighing 68 kg or more); movements were performed on a 3-second count when elevating and lowering the arms. A metronome was used to control the duration of the movements. The examiners observed test movements while standing. Either or both of the following motion abnormalities was considered scapular dyskinesis: (a) The scapula demonstrated premature or excessive elevation or protraction, non-smooth or stuttering motion during arm elevation or lowering, or rapid downward rotation during arm lowering. (b) The medial border and or inferior angle of the scapula were posteriorly displaced away from the posterior thorax ( 12 ). SDT has been used in several studies to determine Scapular dyskinesia and is a well-accepted test ( 5 , 13 ). The validity of this method has been reported between 0.75 and 0.95 ( 14 ). Forward head/shoulder angle measurements To measure head and shoulder posture, photographic method described by Thigpen et al. was used ( 15 ). In this method, the anatomical landmarks of the spinous process of C7 vertebra and the Acromion were determined. Then the subject was asked to stand next to the wall. Then the camera was placed at a suitable distance from the subject and adjusted at a suitable height up to the shoulder level of the subject. The subject was asked to raise and lower his arms and bend forward three times, then stand naturally and look forward. After 5 seconds, three consecutive side view photos were taken. The photos were transferred to Kinovia software. The angle between the tragus and C7 vertical line was calculated as the forward head angle and the angle between the acromion and C7 vertical line was calculated as the forward shoulder angle (Fig. 2 ). This method has been used in many researches and has good reproducibility. The validity of this method has been reported between 0.837 and 0.885. Inter rater reliability of this method have been reported 0.933 and intra-rater reliability has been shown to be between 0.847 and 0.895 ( 15 ). Thoracic kyphosis angle Measurement Thoracic kyphosis angle was measured in a standing position with a flexible ruler (Fig. 3 ). First, C7 and T12 spinous processes were found. Then the flexible ruler was placed on the spinal column to get its shape. Next, the flexible ruler was gently and carefully lifted from the subject’s spine and without altering the configuration of the curve, the examiner placed it on a piece of paper to draw its shape on it. The distance between the C7 and T12 points was drawn and indicated by the letter L. Then we drew a line perpendicular to the L line in the deepest part of the curve and it was named with the letter H. By inserting the obtained values in the formula, the kyphosis angle was obtained (θ = 4Arctan2𝐻/𝐿). The reproducibility of measuring kyphosis by a flexible ruler has been reported to be excellent ( 16 , 17 ). Shoulder internal and external rotation range of motion measurements A goniometer was used to measure the range of motion of internal and external rotation of the shoulder. The measurement was carried out while lying supine with 90 degrees of arm abduction and 90 degrees of elbow flexion. The axis of the goniometer was placed on the elbow joint, the fixed arm was perpendicular to the ground and along the humerus, and the mobile arm was placed along the lower ulna. After keeping the scapula stable, internal and external rotation of the shoulder was recorded in degrees (Fig. 4 ) ( 18 ). Statistical analysis Shapiro-Wilk test was used to check the normality of the distribution of data. Independent t-test was used to compare the two groups. All statistical analyzes were used in the SPSS version 25 and at a significance level of 0.05. Results The demographic information of the participants is shown in Table 1 . Table 1 Baseline characteristics of the participants, differentiated by groups group general characteristics mean standard deviation sig Healthy (n = 25) Age 19.48 1.58 0.057 Height 183.80 4.97 0.418 Weight 92.20 6.33 0.429 Dyskinesia (n = 25) Age 20.28 1.88 0.311 Height 189.40 5.95 0.516 Weight 92.24 5.61 0.228 The comparison of the results of the tests of homogeneity of variances and independent t are shown in Table 2 . Table 2 Comparison of variables in two healthy and dyskinesia groups Variable Group mean ± standard deviation Leven test t F Sig T Df Sig Std. error Forward head Healthy 34.44 ± 5.74 0.400 0.530 -2.040 48 0.047 1.70 Dyskinesia 37.92 ± 6.30 Forward shoulder Healthy 39.68 ± 6.61 1.43 0.273 2.83 48 0.007 2.00 Dyskinesia 45.36 ± 7.53 kyphosis Healthy 30.68 ± 5.39 0.853 0.360 -2.14 48 0.037 1.62 Dyskinesia 34.16 ± 6.04 internal rotation Healthy 71.96 ± 6.93 0.979 0.327 1.47 48 0.148 2.20 Dyskinesia 68.72 ± 8.54 external rotation Healthy 78.96 ± 4.41 4.91 0.121 7.84 48 0.001 2.11 Dyskinesia 62.36 ± 9.61 As shown in Table 2 , the results showed a significant difference in forward head (P = 0.047), forward shoulder (P = 0.007) and thoracic kyphosis (P = 0.037) and shoulder external rotation (P = 0.001) between healthy volleyball players and volleyball players with scapular dyskinesia. However, there was no significant difference in internal rotation of the shoulder between the two groups (P = 0.148). Discussion Our results showed a significant difference in upper-body posture of volleyball players with and without scapular dyskinesia. We did not find any study comparing the posture of volleyball players with and without scapular dyskinesia, but studies have been carried out on the posture of people with other injuries such as shoulder impingement syndrome. Studies have shown that forward head and forward shoulders are common in patients with impingement syndrome ( 19 , 20 ). Sepehrifar et al. stated that forward head and forward shoulder causes neuromusculoskeletal problems and impairments in the positioning of the scapula, which may lead to compensatory movement patterns of the shoulder during upper limb elevation. Therefore, the presence of such deformities can cause the shoulder to suffer from overuse syndrome. In their research, they showed that the correction of the forward head and forward shoulder deformity could lead to the improvement of the shoulder movement patterns ( 21 ). Greenfield et al. concluded that forward head and shoulder posture is significantly more common in shoulder overuse patients than healthy subjects. But their results showed no significant differences in thoracic spine curvature in shoulder overuse patients and healthy subjects ( 22 ). Tooth et al. (2020), studied the electromyographic activity of the muscles of athletes with and without scapular dyskinesia. They observed an increase in the activity of the upper trapezius muscle and a decrease in the activity of the lower trapezius. They also reported that the electromyographic activity of serratus anterior muscle is greater in healthy individuals than that of individuals with dyskinesia ( 23 ). An interesting point to note is that in people with upper crossed syndrome (having forward head, forward shoulder and kyphosis deformities) the upper trapezius and pectoralis major and minor muscles are hyperactive, and the lower trapezius and rhomboid muscles are underactive ( 24 ). This can justify our results that volleyball players with scapular dyskinesia had poorer posture in upper body. We found that shoulder range of motion was limited in athletes with dyskinesia compared to healthy volleyball players, though the range of motion of internal rotation difference was not statistically significant. Studies have shown a significant relationship between scapular dyskinesia and range of motion of shoulder internal and external rotation ( 8 , 25 ). Nodehi et al. reported that the shoulder range of motion in patients with shoulder impingement syndrome is greater than that of healthy individuals ( 20 ). Daneshjoo and Hosseini found that the range of motion of internal and external rotation of the shoulder of volleyball players with asymmetric shoulder is restricted ( 26 ). Pashaei et al. did not find a significant relationship between scapular dyskinesia and shoulder external rotation range of motion, but their results were significant for shoulder internal rotation. Also, they did not report a significant relationship between scapular movement impairment and scapular internal and external rotation strength ( 27 ). Movement patterns of specific skills such as spikes and serves in volleyball create adaptations in the muscle groups around the shoulder and lead to hyperactivity of some muscles ( 28 ). Biomechanical studies in people who overuse their shoulder show that the internal rotator and shoulder adductor muscles are stronger and bulkier than their antagonists. This causes muscle imbalance, which in turn leads to forward shoulder posture. In addition, impaired scapular protraction may cause kyphosis and forward shoulders, which over time leads to the shortening of the muscles in front of the shoulder, such as the pectoralis muscles ( 21 ). In the present study, postural problems such as forward shoulder were observed in volleyball players with scapular dyskinesia, and this problem can be considered as one of the reasons for the limitation of external rotation compared to internal rotation of the shoulder. Because in forward shoulder posture, the glenoid fossa leans forward and downward, the first osteokinematic movement that is affected is external rotation ( 29 ). Conclusion Forward head, forward shoulder and kyphosis angles are greater in volleyball players with scapular dyskinesia than those of volleyball players without scapular dyskinesia. This condition can change the position of the scapula and restrict the range of motion of the shoulder joint. For future studies, it is suggested to investigate shoulder and scapular muscle imbalance and electromyographic activity of the muscles around the scapula in volleyball players with scapular dyskinesia. Declarations Ethics approval and consent to participate We confirm that all experiments were performed in accordance with relevant guidelines and regulations. Authors confirm experiments on humans and the use of human tissue samples confirm that all experiments were performed in accordance with relevant guidelines and regulations. The studies involving human/animal participants were reviewed and approved by Urmia Univercity ethics committee. Also, all methods were carried out in accordance with relevant guidelines and regulations and the study procedures were explained, and informed consent was obtained from all participants and their parents prior to study initiation. Consent for publication Not Applicable Availability of data and materials All data generated or analyzed during this study are included in this published article and its supplementary files. Competing interests The authors declare that they have no competing interests Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Authors' contributions The A author (Fazel Pashaie) was the data collector. The B author (Sajad Roshani) was responsible for explaining, analyzing and writing the discussion. The C author (Hamed Mahmoudi) was responsible for supervising the data collection and the research implementation process. All authors read and approved the final manuscript. Acknowledgments We would like to thank all the participants in this study References Borms D, Cools A. Upper-extremity functional performance tests: reference values for overhead athletes. Int J Sports Med. 2018;39(06):433–41. 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Infraspinatus strength assessment before and after scapular muscles rehabilitation in professional volleyball players with scapular dyskinesis. J Shoulder Elbow Surg. 2010;19(8):1256–64. 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-3969637","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":275354258,"identity":"eec66e7a-cc28-427e-a400-88bd00a74fb5","order_by":0,"name":"Fazel Pashaie","email":"","orcid":"","institution":"Urmia University","correspondingAuthor":false,"prefix":"","firstName":"Fazel","middleName":"","lastName":"Pashaie","suffix":""},{"id":275354259,"identity":"c658e157-ed06-416c-a553-584d9778483e","order_by":1,"name":"Sajad Roshani","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3klEQVRIie3RMWrDMBiG4c8I/ixys9oEnCsoGDLmLBGBTKYUvAQyxNPvQ2TIIbpkVNDgRQfI6j1Luxky1KGdOsgOXTroHQQSPPCBgFDovxZVAE36A+r7wYwj0jxLkKxHbppXcdt259XrS3pbfl7fVpjWJrI7D1Fmkuex25Q0K/JjoTZI3BoX5yMgmkUsNPdEFEoAV+BSeYcRpR0fNKfuQQ6YDxEYoiRmqzmRD2KhhoiyJPKYG81yW/akkQunK/+wmqO2470+1fZdFPd9ljXWfniHiV93+fNNoVAoFPpLX7MlQ2LfYyZWAAAAAElFTkSuQmCC","orcid":"","institution":"Urmia University","correspondingAuthor":true,"prefix":"","firstName":"Sajad","middleName":"","lastName":"Roshani","suffix":""},{"id":275354261,"identity":"ea353b6d-3bb5-42e1-a714-d4cdd13346e4","order_by":2,"name":"Hamed Mahmoudi","email":"","orcid":"","institution":"Department of Education of the first district of Urmia","correspondingAuthor":false,"prefix":"","firstName":"Hamed","middleName":"","lastName":"Mahmoudi","suffix":""}],"badges":[],"createdAt":"2024-02-19 09:45:56","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3969637/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3969637/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":52040322,"identity":"13f9c2a0-1e61-4e13-81c4-1b1dc1bf2b7d","added_by":"auto","created_at":"2024-03-05 17:47:01","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":59274,"visible":true,"origin":"","legend":"\u003cp\u003eScapular dyskinesia measurement\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-3969637/v1/e842566ba537bb1312642f11.jpeg"},{"id":52039096,"identity":"eb139357-015a-4e13-8512-a7778c384924","added_by":"auto","created_at":"2024-03-05 17:39:01","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":96435,"visible":true,"origin":"","legend":"\u003cp\u003eforward head and shoulder angle measurements\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-3969637/v1/1a1de290d5efc7b951c5df95.png"},{"id":52040323,"identity":"ba0fd502-aee5-4d6f-9575-7a4a1572cace","added_by":"auto","created_at":"2024-03-05 17:47:02","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":215728,"visible":true,"origin":"","legend":"\u003cp\u003eThoracic kyphosis angle Measurement\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-3969637/v1/d034ee3a39774da946b0b789.png"},{"id":52039099,"identity":"575b1707-2495-46ee-b133-a1f44219b405","added_by":"auto","created_at":"2024-03-05 17:39:02","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":157701,"visible":true,"origin":"","legend":"\u003cp\u003eShoulder internal and external rotation range of motion measurements\u003c/p\u003e","description":"","filename":"floatimage4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-3969637/v1/4285bed357e07e5274a04a2b.jpeg"},{"id":53637667,"identity":"7c3dab34-b1ce-4c22-84d0-3c3de85ea3a1","added_by":"auto","created_at":"2024-03-28 11:20:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":551336,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3969637/v1/c862995a-cbc7-4a89-964a-5834722d70e9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Comparison of upper body posture, shoulder range of motion of volleyball players with and without scapular dyskinesia","fulltext":[{"header":"Introduction","content":"\u003cp\u003eVolleyball is considered one of the most popular sports and at the same time with a high risk of injury. Some volleyball skills require the engagement of the shoulder girdle while the upper limb is positioned overhead (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Repetitive overhead movements cause disorders in the shoulder girdle movement, scapulohumeral rhythm, and injury to the shoulder joint (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eScapular dyskinesia may be associated with symptoms such as muscle imbalance and limited shoulder range of motion, asymmetric posture, winged scapula, and shoulder instability. Scapular dyskinesia usually occurs due to muscle imbalance of the scapular stabilizers. If the scapular stabilizers do not work properly, the movements of the scapula will also be affected, and this problem will cause more stress on the shoulder joint capsule and cause injury (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). The position of the scapula determines the position of the glenoid fossa and the head of the humerus relative to the acromion. Therefore, the size of the space under the acromion and related injuries depends on the position of the scapula (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eScapular Protraction which occurs as a result of muscle imbalance caused by repeated movements, can cause forward shoulder deformity. With this deformity, due to the change in the position of the scapula, the shoulder joint range of motion and the scapulohumeral rhythm can be affected (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Also, forward shoulder posture leads to anterior tilt and incomplete upward rotation of the scapula during overhead movements and ultimately causes pain in the shoulder area (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). On the other hand, an increase in thoracic kyphosis can cause scapular Protraction and a decrease in the range of motion of the glenohumeral joint (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eStudies that investigated shoulder range of motion and performance of athletes with scapular dyskinesia have reported different results. Klarsen et al. reported a decrease in shoulder external rotation range of motion in subjects with scapular dyskinesia (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Impairments in movement patterns, range of motion limitation and shoulder deformities can lead to poor skills and athlete's performance (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). But Amasai et al. studying the relationship between scapular dyskinesia and upper limb functional test, observed that people with scapular dyskinesia had higher score than healthy people (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). On the other hand, the results of Manukas et al.'s research showed that there is no significant difference between the performance score of people with and without scapular dyskinesia (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). In addition, we found no studies that investigated the posture of athletes with scapular dyskinesia. Therefore, the purpose of this study is to compare upper body posture, shoulder range of motion of volleyball players with and without scapular dyskinesia.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e This study has been approved under the supervision of Urmia University Ethics Committee. The statistical population included all volleyball players from Urmia who were playing professionally at the national league. 25 healthy volleyball players were selected randomly and 25 volleyball players with scapular dyskinesia were selected purposefully as the statistical sample.\u003c/p\u003e \u003cp\u003eEntry criteria included male volleyball players participating in national league, having general health, normal body mass index, no history of fractures and dislocations in the shoulder girdle joints, and a positive scapular dyskinesia test for the scapular dyskinesia group. Exclusion criteria included presence of pain in the shoulder joint during range of motion and refusal to continue cooperation in the research process.\u003c/p\u003e \u003cp\u003e After fully explaining the research process to participants, those who agreed to take part in our study signed a written informed consent. All evaluations for each subject were performed in one session of approximately 30 minutes.\u003c/p\u003e \u003cp\u003eScapular dyskinesia measurement\u003c/p\u003e \u003cp\u003eObservational dyskinesis test (SDT) described by McClure et al. was used to diagnose scapular dyskinesia(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). In this test, participants were asked to remove their shirts during the study to allow observation of the posterior thorax and scapula, and they were asked to perform five repetitions of bilateral active shoulder flexion and five repetitions of bilateral shoulder abduction. Dumbbell weighted test movements were performed according to body weight (2.5 kg for those weighing 68 kg or more); movements were performed on a 3-second count when elevating and lowering the arms. A metronome was used to control the duration of the movements. The examiners observed test movements while standing. Either or both of the following motion abnormalities was considered scapular dyskinesis: (a) The scapula demonstrated premature or excessive elevation or protraction, non-smooth or stuttering motion during arm elevation or lowering, or rapid downward rotation during arm lowering. (b) The medial border and or inferior angle of the scapula were posteriorly displaced away from the posterior thorax (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). SDT has been used in several studies to determine Scapular dyskinesia and is a well-accepted test (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). The validity of this method has been reported between 0.75 and 0.95 (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eForward head/shoulder angle measurements\u003c/p\u003e \u003cp\u003eTo measure head and shoulder posture, photographic method described by Thigpen et al. was used (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). In this method, the anatomical landmarks of the spinous process of C7 vertebra and the Acromion were determined. Then the subject was asked to stand next to the wall. Then the camera was placed at a suitable distance from the subject and adjusted at a suitable height up to the shoulder level of the subject. The subject was asked to raise and lower his arms and bend forward three times, then stand naturally and look forward. After 5 seconds, three consecutive side view photos were taken. The photos were transferred to Kinovia software. The angle between the tragus and C7 vertical line was calculated as the forward head angle and the angle between the acromion and C7 vertical line was calculated as the forward shoulder angle (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). This method has been used in many researches and has good reproducibility. The validity of this method has been reported between 0.837 and 0.885. Inter rater reliability of this method have been reported 0.933 and intra-rater reliability has been shown to be between 0.847 and 0.895 (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThoracic kyphosis angle Measurement\u003c/p\u003e \u003cp\u003eThoracic kyphosis angle was measured in a standing position with a flexible ruler (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). First, C7 and T12 spinous processes were found. Then the flexible ruler was placed on the spinal column to get its shape. Next, the flexible ruler was gently and carefully lifted from the subject\u0026rsquo;s spine and without altering the configuration of the curve, the examiner placed it on a piece of paper to draw its shape on it. The distance between the C7 and T12 points was drawn and indicated by the letter L. Then we drew a line perpendicular to the L line in the deepest part of the curve and it was named with the letter H. By inserting the obtained values in the formula, the kyphosis angle was obtained (θ\u0026thinsp;=\u0026thinsp;4Arctan2\u0026#119867;/\u0026#119871;). The reproducibility of measuring kyphosis by a flexible ruler has been reported to be excellent (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eShoulder internal and external rotation range of motion measurements\u003c/p\u003e \u003cp\u003eA goniometer was used to measure the range of motion of internal and external rotation of the shoulder. The measurement was carried out while lying supine with 90 degrees of arm abduction and 90 degrees of elbow flexion. The axis of the goniometer was placed on the elbow joint, the fixed arm was perpendicular to the ground and along the humerus, and the mobile arm was placed along the lower ulna. After keeping the scapula stable, internal and external rotation of the shoulder was recorded in degrees (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e) (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eShapiro-Wilk test was used to check the normality of the distribution of data. Independent t-test was used to compare the two groups. All statistical analyzes were used in the SPSS version 25 and at a significance level of 0.05.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eThe demographic information of the participants is shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\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\u003eBaseline characteristics of the participants, differentiated by groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\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=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003egroup\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003egeneral characteristics\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003emean\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003estandard deviation\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003esig\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eHealthy\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;25)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e19.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.057\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHeight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e183.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.418\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eWeight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e92.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.429\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eDyskinesia\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;25)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e20.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.311\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHeight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e189.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.516\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eWeight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e92.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.228\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\u003eThe comparison of the results of the tests of homogeneity of variances and independent t are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of variables in two healthy and dyskinesia groups\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 \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003emean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003eLeven test\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c9\" namest=\"c7\"\u003e \u003cp\u003et\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSig\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eDf\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSig\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eStd. error\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eForward head\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHealthy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e34.44\u0026thinsp;\u0026plusmn;\u0026thinsp;5.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.400\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.530\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e-2.040\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.047\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e1.70\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDyskinesia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37.92\u0026thinsp;\u0026plusmn;\u0026thinsp;6.30\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eForward shoulder\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHealthy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e39.68\u0026thinsp;\u0026plusmn;\u0026thinsp;6.61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e1.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.273\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e2.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e2.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDyskinesia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e45.36\u0026thinsp;\u0026plusmn;\u0026thinsp;7.53\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003ekyphosis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHealthy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.68\u0026thinsp;\u0026plusmn;\u0026thinsp;5.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.853\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.360\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e-2.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.037\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e1.62\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDyskinesia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e34.16\u0026thinsp;\u0026plusmn;\u0026thinsp;6.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003einternal rotation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHealthy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e71.96\u0026thinsp;\u0026plusmn;\u0026thinsp;6.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.979\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.327\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e1.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.148\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e2.20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDyskinesia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e68.72\u0026thinsp;\u0026plusmn;\u0026thinsp;8.54\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eexternal rotation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHealthy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e78.96\u0026thinsp;\u0026plusmn;\u0026thinsp;4.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e4.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.121\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e7.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e2.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDyskinesia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e62.36\u0026thinsp;\u0026plusmn;\u0026thinsp;9.61\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\u003eAs shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, the results showed a significant difference in forward head (P\u0026thinsp;=\u0026thinsp;0.047), forward shoulder (P\u0026thinsp;=\u0026thinsp;0.007) and thoracic kyphosis (P\u0026thinsp;=\u0026thinsp;0.037) and shoulder external rotation (P\u0026thinsp;=\u0026thinsp;0.001) between healthy volleyball players and volleyball players with scapular dyskinesia. However, there was no significant difference in internal rotation of the shoulder between the two groups (P\u0026thinsp;=\u0026thinsp;0.148).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur results showed a significant difference in upper-body posture of volleyball players with and without scapular dyskinesia. We did not find any study comparing the posture of volleyball players with and without scapular dyskinesia, but studies have been carried out on the posture of people with other injuries such as shoulder impingement syndrome. Studies have shown that forward head and forward shoulders are common in patients with impingement syndrome (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). Sepehrifar et al. stated that forward head and forward shoulder causes neuromusculoskeletal problems and impairments in the positioning of the scapula, which may lead to compensatory movement patterns of the shoulder during upper limb elevation. Therefore, the presence of such deformities can cause the shoulder to suffer from overuse syndrome. In their research, they showed that the correction of the forward head and forward shoulder deformity could lead to the improvement of the shoulder movement patterns (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e). Greenfield et al. concluded that forward head and shoulder posture is significantly more common in shoulder overuse patients than healthy subjects. But their results showed no significant differences in thoracic spine curvature in shoulder overuse patients and healthy subjects (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eTooth et al. (2020), studied the electromyographic activity of the muscles of athletes with and without scapular dyskinesia. They observed an increase in the activity of the upper trapezius muscle and a decrease in the activity of the lower trapezius. They also reported that the electromyographic activity of serratus anterior muscle is greater in healthy individuals than that of individuals with dyskinesia (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e). An interesting point to note is that in people with upper crossed syndrome (having forward head, forward shoulder and kyphosis deformities) the upper trapezius and pectoralis major and minor muscles are hyperactive, and the lower trapezius and rhomboid muscles are underactive (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). This can justify our results that volleyball players with scapular dyskinesia had poorer posture in upper body.\u003c/p\u003e \u003cp\u003eWe found that shoulder range of motion was limited in athletes with dyskinesia compared to healthy volleyball players, though the range of motion of internal rotation difference was not statistically significant. Studies have shown a significant relationship between scapular dyskinesia and range of motion of shoulder internal and external rotation (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e). Nodehi et al. reported that the shoulder range of motion in patients with shoulder impingement syndrome is greater than that of healthy individuals (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). Daneshjoo and Hosseini found that the range of motion of internal and external rotation of the shoulder of volleyball players with asymmetric shoulder is restricted (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e). Pashaei et al. did not find a significant relationship between scapular dyskinesia and shoulder external rotation range of motion, but their results were significant for shoulder internal rotation. Also, they did not report a significant relationship between scapular movement impairment and scapular internal and external rotation strength (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eMovement patterns of specific skills such as spikes and serves in volleyball create adaptations in the muscle groups around the shoulder and lead to hyperactivity of some muscles (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e). Biomechanical studies in people who overuse their shoulder show that the internal rotator and shoulder adductor muscles are stronger and bulkier than their antagonists. This causes muscle imbalance, which in turn leads to forward shoulder posture. In addition, impaired scapular protraction may cause kyphosis and forward shoulders, which over time leads to the shortening of the muscles in front of the shoulder, such as the pectoralis muscles (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e). In the present study, postural problems such as forward shoulder were observed in volleyball players with scapular dyskinesia, and this problem can be considered as one of the reasons for the limitation of external rotation compared to internal rotation of the shoulder. Because in forward shoulder posture, the glenoid fossa leans forward and downward, the first osteokinematic movement that is affected is external rotation (\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e).\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eForward head, forward shoulder and kyphosis angles are greater in volleyball players with scapular dyskinesia than those of volleyball players without scapular dyskinesia. This condition can change the position of the scapula and restrict the range of motion of the shoulder joint. For future studies, it is suggested to investigate shoulder and scapular muscle imbalance and electromyographic activity of the muscles around the scapula in volleyball players with scapular dyskinesia.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe confirm that all experiments were performed in accordance with relevant guidelines and regulations. Authors confirm experiments on humans and the use of human tissue samples confirm that all experiments were performed in accordance with relevant guidelines and regulations. The studies involving human/animal participants were reviewed and approved by Urmia Univercity ethics committee. Also, all methods were carried out in accordance with relevant guidelines and regulations and the study procedures were explained, and informed consent was obtained from all participants and their parents prior to study initiation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot Applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data generated or analyzed during this study are included in this published article and its supplementary files.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe A author (Fazel Pashaie)\u0026nbsp;was the data collector. The B author (Sajad Roshani)\u0026nbsp;was responsible for explaining, analyzing and writing the discussion. The C author (Hamed Mahmoudi)\u0026nbsp;was responsible for supervising the data collection and the research implementation process. All authors read and approved the final manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe would like to thank all the participants in this study\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBorms D, Cools A. Upper-extremity functional performance tests: reference values for overhead athletes. Int J Sports Med. 2018;39(06):433\u0026ndash;41.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGouttebarge V, van Sluis M, Verhagen E, Zwerver J. The prevention of musculoskeletal injuries in volleyball: the systematic development of an intervention and its feasibility. 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Int J Anat Appl Physiol. 2016;2(2):20\u0026thinsp;\u0026ndash;\u0026thinsp;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eManokas S, Amasay T, Arbel V, editors. The effect of scapular dyskinesis on upper quarter y-balance test performance. International Journal of Exercise Science: Conference Proceedings; 2020.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcClure P, Tate AR, Kareha S, Irwin D, Zlupko E. A clinical method for identifying scapular dyskinesis, part 1: reliability. J Athl Train. 2009;44(2):160\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBen Kibler W. The role of the scapula in athletic shoulder function. Am J Sports Med. 1998;26(2):325\u0026ndash;37.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTate AR, McClure P, Kareha S, Irwin D, Barbe MF. A clinical method for identifying scapular dyskinesis, part 2: validity. 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JOURNAL OF NURSE AND PHYSICIAN WITHIN WAR. 2014;2(3):56\u0026ndash;63.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGreenfield B, Catlin PA, Coats PW, Green E, McDonald JJ, North C. Posture in patients with shoulder overuse injuries and healthy individuals. J Orthop Sports Phys Therapy. 1995;21(5):287\u0026ndash;95.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTooth C, Schwartz C, Croisier J-L, Bornheim S, Br\u0026uuml;ls O, Deno\u0026euml;l V, Forthomme B. Activation Profile of Scapular Stabilizing Muscles in Asymptomatic People: Does Scapular Dyskinesis Have an Impact on It? Am J Phys Med Rehabil. 2020;99(10):925\u0026ndash;31.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJanda V. Muscle strength in relation to muscle length, pain and muscle imbalance. Int Perspect Phys Therapy. 1993:83-.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eThomas SJ, Swanik KA, Swanik CB, Kelly IVJD. Internal rotation deficits affect scapular positioning in baseball players. Clin Orthop Relat Research\u0026reg;. 2010;468(6):1551\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDaneshjoo A, Hosseini T. Strength and range of motion of internal and external rotator muscles in volleyball players with and without uneven shoulders. J Sport Biomech. 2019;5(3):134\u0026ndash;45.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePashaei Z, Daneshmandi H, Norasteh A, Fatahi A. Relationship between Scapular Movement Impairment and Shoulder Girdle Strength\u0026lrm; and Range of Motion in Professional Male volleyball players. J Paramedical Sci Rehabilitation. 2022;11(2):35\u0026ndash;47.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrush\u0026oslash;j C, Bak K, Johannsen H, Faun\u0026oslash; P. Swimmers' painful shoulder arthroscopic findings and return rate to sports. Scand J Med Sci Sports. 2007;17(4):373\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMerolla G, De Santis E, Sperling JW, Campi F, Paladini P, Porcellini G. Infraspinatus strength assessment before and after scapular muscles rehabilitation in professional volleyball players with scapular dyskinesis. J Shoulder Elbow Surg. 2010;19(8):1256\u0026ndash;64.\u003c/span\u003e\u003c/li\u003e\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":"scapular dyskinesia, range of motion, volleyball player, posture","lastPublishedDoi":"10.21203/rs.3.rs-3969637/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3969637/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eRepetitive movement patterns and continuous use of the upper limb in volleyball cause scapular movement disorders. The aim of the present study was to compare upper body posture, shoulder range of motion of volleyball players with and without scapular dyskinesia.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003e50 volleyball players (25 volleyball players with scapular dyskinesia and 25 healthy volleyball players) were selected in a targeted manner from volleyball clubs in Urmia city. Head and shoulder posture were evaluated using photography. The thoracic spine was assessed by a flexible ruler; internal and external rotation of the shoulder using a goniometer. In order to compare the means of the two groups, independent t-test was used.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe results showed a significant difference in forward head (P\u0026thinsp;=\u0026thinsp;0.047), forward shoulder (P\u0026thinsp;=\u0026thinsp;0.007) and thoracic spine posture (P\u0026thinsp;=\u0026thinsp;0.037), and shoulder external rotation (P\u0026thinsp;=\u0026thinsp;0.001) between healthy volleyball players and volleyball players with scapular dyskinesia. However, there was no significant difference in internal rotation of the shoulder (P\u0026thinsp;=\u0026thinsp;0.148) between the two groups.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eshoulder girdle posture of volleyball players with scapular dyskinesia seems to be poorer than that of volleyball players without scapular dyskinesia. Players with scapular dyskinesia had limited external rotation range compared to the healthy group. This issue may be affected by the position of the shoulder, which itself can be caused by a poor posture.\u003c/p\u003e","manuscriptTitle":"Comparison of upper body posture, shoulder range of motion of volleyball players with and without scapular dyskinesia","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-05 17:38:57","doi":"10.21203/rs.3.rs-3969637/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":"515498f2-b89b-4823-8b7c-6ccc767a16c5","owner":[],"postedDate":"March 5th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-03-28T11:12:51+00:00","versionOfRecord":[],"versionCreatedAt":"2024-03-05 17:38:57","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3969637","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3969637","identity":"rs-3969637","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}