Upper extremity field tests and isokinetic shoulder internal and external strength and power in sports active males

Abstract

BACKGROUND: In order to guide sports active subjects with musculoskeletal (MSK) shoulder dysfunctions it is essential to have precise insights of possible weak links in the kinetic chain of their shoulder girdle with access to reference data. Equally, it is uncertain whether so-called functional shoulder strength tests are complementary to an isokinetic shoulder strength test. OBJECTIVE: To establish reference values and to clarify the relationship between two upper extremity field tests – the Scapular Muscle Endurance test (SME) and the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST) and the isokinetic strength test of the shoulder internal (IR) and external rotators (ER). METHODS: Seventy-six male sport active men performed the CKCUEST, the SME, and underwent a bilateral isokinetic strength test to establish reference values of the isokinetic shoulder relative to body mass Peak Moment (PM/kg) and Power (Power/kg) for the IR and ER. A mixed-design ANOVA calculated possible side-to-side differences and one-way ANOVA was applied for eventually age group differences. Additionally, the relationship between the three tests was examined with a Spearman rank-order correlation coefficient. RESULTS: No significant correlations were indicated between the SME and the criterion isokinetic test and between the SME and CKCUEST. CONCLUSIONS: The main outcome parameters in this study warrant individual assessment as they measure different constructs, leading to a diverse profile of the shoulder.