Short‐Term Clinical Comparison of Scapular Stabilization With and Without Added Kinetic‐Chain Exercises on Pain, Scapular Kinematics, and Upper‐Extremity Function in Overhead Athletes With Subacromial Pain Syndrome: A Randomized Controlled Trial
Seyede Sayeh Moosavi Chavoshi, Kazem Malmir, Khadijah Otadi, Azadeh Shadmehr, Khosro Khademi KalantariABSTRACT
Background and Purpose
Scapular stabilization exercises are commonly used in the rehabilitation of athletes with subacromial pain syndrome (SAPS) and scapular dyskinesis. Whether supplementing scapular stabilization with kinetic‐chain exercises provides greater short‐term benefits remains uncertain. This study compared the short‐term effects of a scapular stabilization program alone with those of the same program supplemented with additional kinetic‐chain exercises.
Methods
Twenty‐four overhead athletes with SAPS and scapular dyskinesis were randomly assigned to a scapular stabilization group ( n = 12) or a kinetic‐chain‐supplemented group ( n = 12). Both groups performed the same standardized scapular stabilization program; the latter also performed additional trunk, lower‐extremity, balance, and multisegment exercises, resulting in a greater overall exercise stimulus. Outcomes were assessed before and after 4 weeks. The prespecified primary outcome was scapular upward rotation at 90° shoulder elevation. Between‐group differences were analyzed using two‐way mixed repeated‐measures ANOVA, with the group × time interaction as the principal test, and reported with 95% confidence intervals. Holm–Bonferroni adjustment and baseline‐adjusted ANCOVA were conducted as sensitivity analyses.
Results
For the prespecified primary outcome, scapular upward rotation at 90°, the group × time interaction was not statistically significant ( p = 0.052; ηp 2 = 0.161), with a between‐group difference in change of −4.38° (95% CI, −8.80° to 0.03°). After Holm–Bonferroni adjustment for the 15 group × time comparisons, the primary outcome remained nonsignificant (adjusted p = 0.723). The baseline‐adjusted ANCOVA also showed no statistically significant between‐group difference (−3.51°, 95% CI, −7.33° to 0.31°; p = 0.070); however, the significant group × baseline interaction ( p = 0.002) indicated that the homogeneity‐of‐regression‐slopes assumption was not met. An unadjusted significant group × time interaction was observed for scapular upward rotation at 45° ( p = 0.028), but this finding did not remain significant after Holm–Bonferroni adjustment (adjusted p = 0.426). No other group × time interaction remained statistically significant after adjustment for multiple comparisons.
Conclusion
Both rehabilitation programs were associated with short‐term improvements in patient‐reported outcomes. However, adding kinetic‐chain exercises did not result in a clear additional short‐term benefit compared with scapular stabilization alone. Because the kinetic‐chain group also completed more exercises overall, the specific contribution of the kinetic‐chain component cannot be determined. Given the small sample size and uncertainty surrounding the primary outcome, smaller but potentially meaningful differences between the programs cannot be excluded.
Trial Registration
IRCT20240614062130N1, registered July 20, 2024