Abstract des Autors

Isokinetic, shoulder rotational strength was evaluated in 26 high school baseball pitchers before the start of spring practice. Using the Cybex II, test data were gathered on the dominant and nondominant shoulders in the supine 90x abducted test position (90deg ABTP) and the standing neutral test position (neutral TP). Tests were performed at 90 and 240 deg/sec. The HUMAC computer system was used to analyze data. Means and standard deviations for peak torque, total work, peak torque to body weight ratios, and agonist/antagonist ratios are presented. Comparison of dominant to nondominant sides and 90deg ABTP to neutral TP values are reported. Peak torque and total work values for the throwing side internal rotators were significantly higher than the nonthrowing side in all tests. Pitching side external rotators failed to show this dominance. External/internal rotation ratios for peak torque and total work were significantly lower on the pitching side, suggesting a relative imbalance of cuff musculature compared to the nonpitching shoulder. Significant differences existed between data gathered in the two different test positions. In the 90deg ABTP, external rotation peak torque and total work values and external/internal rotation peak torque and total work ratios were higher than the equivalent values gathered in the neutral TP. Internal rotation peak torque and total work values tended to be higher in the neutral TP than in the 90deg ABTP. The rotator cuff imbalances exhibited in the pitching shoulder of participants in this study draw attention to the need for structured exercise to prevent and correct this deficit, which can act as a predisposing factor to injury in the throwing athlete. Significant differences in torque data gathered in two commonly used shoulder rotational test positions suggest the need for multiple position testing for complete evaluation and the requirement of specifying test position when comparing shoulder rotational torque values clinically or experimentally.