Isokinetic profile of baseball pitchers' internal/external rotation 180, 300, 450 degrees.s-1.

Abstract

The purpose of this study was to develop further normative data for an isokinetic profile for intercollegiate baseball pitchers at 180, 300, and 450 degrees.s-1. Information on isokinetic performance at 450 degrees.s-1 was not found in previously published literature. Sixteen intercollegiate baseball pitchers volunteered for isokinetic strength testing of internal and external rotators of the shoulder. The testing was conducted at 180, 300, and 450 degrees.s-1; with the pitchers in a position of function (90 degrees/90 degrees). The subjects were able to reach maximal velocity for each of the speeds tested, including 450 degrees.s-1. These pitchers demonstrated no significant difference between dominant and nondominant arms for peak torque, torque/body weight, work/body weight, or average power (P < 0.05). Torque produced at 0.2 s was significantly greater in the dominant arm compared with the nondominant arm at 450 degrees.s-1 only. Internal rotation values were significantly greater than external rotation values for all areas of comparison. External rotation/internal rotation ratios remained consistent for each speed tested (approximately 0.65). There is minimal difference in strength values between dominant and nondominant arms of intercollegiate baseball pitchers, with the exception of significantly greater internal rotation peak torque at 0.2 s at 450 degrees.s-1 in the dominant arm. Dominant arm, as well as nondominant arm, ER/IR ratios remain consistent throughout the velocity spectrum. A valid test speed for intercollegiate baseball pitchers appears to be 450 degrees.s-1 when tested before the start of throwing from the pitcher's mound.