Effects of Visual and Verbal Feedback on Peak Torque During Isokinetic Testing in Male Athletes

Abstract

Isokinetic testing is often used to assess peak muscle torque, power, and work. Some of the considerable amount of published isokinetic literature reports whether the subjects were provided visual and verbal feedback. Additionally, most protocols use ascending order of velocities without much evidence that this is superior to descending velocity order. PURPOSE: The purpose of the study was to evaluate the effect of visual and verbal feedback on peak torque production in collegiate male athletes when altering the order of velocities. METHODS: Fifteen healthy, college aged males (mean age= 20.27 years, height= 178.99 cm, weight= 85.00 kg) performed two familiarization trials and four randomly assigned experimental trials on a Cybex NORM isokinetic dynamometer using a knee flexion and extension protocol. Subjects performed four repetitions of knee extension at either ascending velocities (60, 120, 180, 240, and 300°/sec) or descending velocities (300, 240, 180, 120, 60°/sec) with knee flexion held constant at 300°/sec. Between each velocity set was a rest period of 60 seconds. A 2 X 2 X 5 repeated measures ANOVA was used to analyze the data (a<.05). RESULTS: There were no significant differences in peak torque in either ascending or descending velocity order when verbal and visual feedback were present or absent. Although not statistically significant, at every velocity when executing ascending order and at 60, 120, 180°/sec during descending order, the subjects increased their peak torque when given visual and verbal feedback. Secondly, there were no significant differences in peak torque when comparing ascending or descending velocity order. CONCLUSIONS: Visual and verbal feedback appear to have some influence on peak torque production, particularly at the slower velocities. Moreover, order of velocity sets does not seem to vary the ability to produce peak torque. Supported by a grant from the University of Puget Sound