AN ECCENTRIC-STRENGTH AND CONCENTRIC-STRENGTH PROFILE OF SHOULDER EXTERNAL AND INTERNAL ROTATOR MUSCLES IN PROFESSIONAL BASEBALL PITCHERS

The purpose of this study was to establish a data base on the isokinet ic eccentric muscular performance characteristics of external and inte rnal rotator muscles in the shoulders of professional baseball pitcher s. Concentric data are also included and compared with previously publ ished concentric studies. Twenty-five professional baseball pitchers w ere evaluated with a Kin-Com isokinetic dynamometer. The subjects test ed had a mean age of 23.5 years and a mean body weight of 199 pounds, Eccentric and concentric isokinetic tests were performed at 60 and 120 deg/sec. The testing protocol was standardized for each subject. Test results indicated no statistically significant difference in mean tor que between throwing and nonthrowing shoulders for either external or internal rotator muscle groups, Eccentric strength was significantly g reater than concentric strength for all muscle groups tested, The exte rnal-to-internal rotator muscle strength ratios were well above those previously published for high school through professional pitchers. Me an torque-to-lean body weight ratios were also included to establish a data base. This study establishes one of the first data bases for ecc entric isokinetic muscle strength of shoulder rotator muscles in profe ssional baseball pitchers. The data may help clinicians prevent and re habilitate shoulder injuries in professional throwing athletes.