Effect of Visual Feedback on Maximal and Submaximal lsokinetic Test Measurements of Normal Quadricem - and Hamstrings

This study investigated the effect of visual feedback on peak torque, relative endurance, time rate of tension development, and submaximal contractions attempted at 50% of maximum peak torque of the quadriceps and hamstring muscle groups. The dominant knee of 18 males and 18 females, between the ages of 20 and 33, completed the two test sessions, 1 week apart, using an isokinetic dynamometer at 60 degrees /sec and 180 degrees /sec. Visual feedback, consisting of a video display of the chart recorder, was provided during one of these sessions, determined at random. With feedback, peak torque at both speeds was significantly greater in both muscle groups. Time rate of tension development at 60 degrees /sec for the quadricep also increased significantly. No differences were found in submaximal contractions at 60 O/sec and relative endurance at 180 degrees /set. J Orthop Sports Phys Ther 1987;9(2):86-93.