Effects of position and speed on eccentric and concentric isokinetic testing of the shoulder rotators.

This study investigated the effects of position and speed on peak torque values of the shoulder internal and external rotators during concentric and eccentric activity. The dominant shoulder of 9 males and 10 females, 21-33 years, were tested at two velocities (60 and 180 degrees /sec) in two positions (45 degrees glenohumeral abduction and 45 degrees glenohumeral flexion) and two contraction types (eccentric and concentric). Results indicated that 1) concentric internal rotation decreased significantly (p < 0.0001) at the higher speed in males, 2) eccentric external rotation increased significantly (p < 0.003) at the higher speed in females, and 3) peak torque values were significantly greater (p < 0.01) in the 45 degrees glenohumeral abduction position compared to the 45 degrees glenohumeral flexion position during eccentric and concentric external rotation for both females and males, and for eccentric internal rotation in females. These findings are useful when planning to progress the intensity of the testing and training of the shoulder rotators according to patient tolerance. J Orthop Sports Phys Ther 1989;11(2):64-69.