Background and Purpose
Scapular dyskinesis is a prevalent functional disorder among young overhead athletes, particularly gymnasts, characterized by abnormal scapular motion and impaired neuromuscular control during upper limb elevation. This condition disrupts scapulohumeral rhythm, alters proprioceptive accuracy, and increases susceptibility to shoulder injuries, pain, and performance deficits. In artistic gymnastics, the upper extremities serve as primary weight-bearing segments, demanding high levels of stability, coordination, and kinetic chain integrity. Despite growing evidence supporting corrective and stabilization exercises, limited research has examined the comprehensive effects of kinetic chain-based scapular exercises on integrated outcomes such as function, rhythm, and joint position sense in pediatric athletes. Therefore, this study aimed to investigate the effects of an eight-week scapular kinetic chain exercise program on shoulder function, scapulohumeral rhythm, and joint position sense in gymnasts with scapular dyskinesis. The findings aim to provide clinical guidance for designing targeted rehabilitation and injury-prevention strategies to optimize shoulder mechanics in youth gymnasts.
 
Methods
This quasi-experimental study employed a pre-test–post-test control group design involving 30 young artistic gymnasts aged 7 to 15 years from Karaj, Iran, all diagnosed with scapular dyskinesis based on the Kibler Scapular Dyskinesis Test and a minimum scapular asymmetry of 1.5 cm. Participants were randomly assigned to either an experimental group (n = 15) or a control group (n = 15). Inclusion criteria included at least three years of regular gymnastics training, absence of upper limb surgery or severe postural deformities, and no current pain or injury affecting performance. Ethical approval was granted by the Sports Sciences Research Institute of Iran (IR.SSRC.REC.1401.060), and written informed consent was obtained from participants and their parents.
The experimental group underwent an eight-week scapular kinetic chain exercise protocol, performed three times per week for 40–60 minutes per session. The program, adapted from Jae et al. (2020), integrated both open and closed kinetic chain movements targeting scapular stabilization, neuromuscular coordination, and postural control. Each session consisted of a 10-minute warm-up, 30–40 minutes of progressive scapular exercises (including wall slides, serratus punches, scapular clock movements, and closed-chain protraction-retraction drills), followed by a 10-minute cool-down with stretching. Exercise intensity was gradually progressed based on participants’ tolerance, ensuring the final repetitions were performed under moderate fatigue.
Outcome measures were assessed pre- and post-intervention. Shoulder function was evaluated using the Upper Quarter Y Balance Test (UQYBT), recorded in medial, inferolateral, and superolateral reach directions. Scapulohumeral rhythm was measured using dual digital goniometry during controlled arm elevation, calculating the ratio between glenohumeral and scapular rotation. Joint position sense (proprioception) was assessed at 45° and 80° of external rotation using active repositioning tests with blinded visual feedback. Data were analyzed using SPSS version 26. Paired t-tests assessed within-group changes, while ANCOVA, controlling for baseline scores, evaluated between-group differences at a significance level of p ≤ 0.05.
 
Results
The analysis of covariance (ANCOVA) revealed significant between-group differences across all post-test measures, underscoring the effectiveness of the 8-week scapular kinetic chain exercise program in improving shoulder function, scapulohumeral rhythm, and joint position sense in gymnasts with scapular dyskinesis. The experimental group demonstrated substantial enhancements in shoulder function, as assessed by the Upper Quarter Y Balance Test (UQYBT). Specifically, medial reach performance improved by 15.2%, increasing from 78.4 ± 5.6 cm to 90.3 ± 4.2 cm normalized (F=13.88, p=0.001), indicating better dynamic stability in the medial direction. Inferolateral reach performance saw an 18.7% improvement, rising from 72.1 ± 6.3 cm to 85.6 ± 5.1 cm (F=20.58, p<0.001), reflecting enhanced control during lateral movements. Superolateral reach performance exhibited the largest gain, improving by 22.4% from 68.9 ± 7.2 cm to 84.3 ± 4.8 cm (F=61.41, p<0.001), suggesting significant improvements in overhead functional reach. The composite UQYBT score, a comprehensive measure of shoulder stability and mobility, increased from 73.1% to 86.7% (p<0.001), highlighting overall functional improvement. Scapulohumeral rhythm showed significant restoration, with the experimental group’s ratio shifting from 2.8:1 to 2.1:1 (F=12.75, p=0.001), aligning closely with the normative 2:1 ratio, which indicates improved coordination between scapular and humeral movements. Joint position sense errors were markedly reduced, with a 45% decrease at 45° external rotation, from 8.2° ± 1.5° to 4.5° ± 1.2° (F=32.11, p<0.001), and a 52% reduction at 80° external rotation, from 10.4° ± 2.1° to 5.0° ± 1.3° (F=73.31, p<0.001), demonstrating enhanced proprioceptive accuracy critical for precise movement control. Within-group analysis using paired t-tests confirmed significant improvements in the experimental group across all measured variables (p<0.001), with effect sizes (Cohen’s d) ranging from 1.2 to 2.5, indicating strong practical significance. In contrast, the control group exhibited no significant changes in any measure (p>0.05), underscoring the specific impact of the intervention. Qualitative observations during training sessions noted improved movement coordination, reduced scapular winging, and greater ease in performing functional tasks among the experimental group, further supporting the statistical findings. These improvements suggest that the intervention effectively addressed underlying neuromuscular deficits, restoring normal scapular kinematics and enhancing shoulder performance in this population.
 
Conclusion
The 8-week scapular kinetic chain exercise program significantly enhanced shoulder function, scapulohumeral rhythm, and joint position sense in gymnasts with scapular dyskinesis. Improvements are likely due to strengthened stabilizing muscles (e.g., serratus anterior, lower trapezius), restored scapular kinematics, and heightened neuromuscular coordination. These exercises facilitated better force coupling and proprioceptive feedback, reducing asymmetry and error in joint repositioning. The findings align with prior studies on overhead athletes, emphasizing the role of kinetic chain integration in rehabilitation.
This intervention supports incorporating scapular-focused kinetic chain training into gymnastics programs for injury prevention and performance optimization. Future research should explore long-term effects, gender-specific responses, and comparisons with other modalities like biofeedback. Limitations include the sample's age restriction and potential confounding from maturation, though controlled. Overall, these exercises offer a safe, effective approach for managing scapular dyskinesis in young athletes, potentially reducing injury incidence and enhancing athletic longevity.
 
Article Message
Scapular kinetic chain exercises can improve shoulder joint function, scapulohumeral rhythm, and proprioception in gymnasts with scapular dyskinesis. These exercises, by strengthening stabilizing muscles and enhancing neuromuscular coordination, are recommended as an effective rehabilitation and preventive approach for overhead athletes.
Ethical Considerations
This study was conducted in accordance with ethical standards of human research. Ethical approval was obtained from the Research Ethics Committee of the Sport Sciences Research Institute of Iran (IR.SSRC.REC.1401.060).
Authors' Contributions
Conceptualization: Hossein Shahrokhi, Hadi Miri
Data Collection: Zahra Moghiseh
Data Analysis: Hossein Shahrokhi, Zahra Moghiseh
Manuscript Writing: Zahra Moghiseh, Ebrahim Ebrahimi
Review and Editing: Hossein Shahrokhi
Literature Review: Ebrahim Ebrahimi
Project Manager: Hossein Shahrokhi
Any other Contributions: All authors read and approved the final manuscript.
Conflict of Interest
The authors declare that there is no conflict of interest.
 
Acknowledgments
The authors sincerely appreciate the cooperation of the young gymnasts and their families, as well as the support of the gymnastics clubs and coaches in Alborz Province. This research was supported by the Sport Sciences Research Institute of Iran.