Isokinetic performance at diagonal pattern and shoulder mobility in elite overhead athletes

The purpose of this study was to measure isokinetically glenohumeral joint movement peak torque and work in professional basketball, volleyball, handball and baseball players and determine whether significant differences exist between the dominant and non-dominant extremity in athletes and controls. Eighty healthy professional overhead athletes (basketball, volleyball, handball and baseball players) and 20 controls were tested bilaterally on a CYBEX 6000 isokinetic dynamometer at 60 degrees and 180 degrees s(-1) for diagonal pattern of the glenohumeral joint. A standardized protocol and testing guidelines were strictly followed. The range of motion of internal rotation (IR) on the dominant side of baseball players was significantly smaller than those on the dominant side of basketball, handball and volleyball players, and controls (P<0.01). Flexion/abduction/external rotation were consistently higher on the dominant arm (8.5%) for peak torque at 60 degrees s(-1) in baseball players, and bilateral ratios were lower on the dominant arm (14.8%) for peak torque at 180 degrees s(-1) in basketball players. The results of this study are important for the application and interpretation of isokinetic data and flexibility and mobility characteristics on unilaterally dominant overhead athletes. Functional weakness in external rotators, mobility impairments in IR and muscle imbalance have been shown in the dominant arm of these overhead athletes.