Is There a Relation Between Shoulder Dysfunction and Core Instability?

BACKGROUND Overhead athletes often suffer injury to the glenohumeral joint secondary to inherent instability. However, little is known about the relationship between core stability and shoulder dysfunction among athletes. PURPOSE The purpose of this study was to analyze the difference between healthy athletes and those with shoulder dysfunction in regard to core stability measures. Secondary purpose was to explore the relationship between measures of core stability and measures of shoulder dysfunction. METHODS Participants consisted of NCAA Division III overhead athletes (28 males, 33 females) with a mean age of 19.3 ± (1.1) years, mean weight of 173.6 ± (36.9) pounds, mean height of 67.8 ± (3.5) inches. Functional questionnaires (the Kerlan-Jobe Orthopaedic Clinical Scale [KJOC] and the QuickDASH sports module) as well as Single-Leg Stance Balance Test (SLBT), Double Straight Leg Lowering Test (DLL), Sorensen Test, and Modified Side Plank Test were completed in a randomized order with consistent raters. RESULTS MANOVA was significant at (p = .038) for the comparison between the experimental group and the control group for the values of Right SLBT. The experimental group had significantly less balance than the control group with means of 10.14 ± (5.76) seconds and 18.98 ± (15.22) seconds respectively. Additionally, a positive correlation was found between the DLL and the KJOC at (r = .394, p > .05) and a negative correlation was found between the Right SLBT and the Quick DASH sports module (QD) at (r = -.271, p > .05). DISCUSSION AND CONCLUSION Balance deficiency was found in athletes with shoulder dysfunction. According to this study, greater shoulder dysfunction is correlated with greater balance and stability deficiency. Therapists and trainers should consider incorporating balance training as an integral component of core stability into rehabilitation of athletes with shoulder dysfunction. LEVEL OF EVIDENCE 3b.