Abstract
Isokinetic normative data can be invaluable in identifying an individual’s strengths and
weaknesses, and thus lead to a more effective use of the individual’s time to minimise or
overcome his weaknesses while maintaining or improving existing strength. However, visual
feedback (VF) may significantly affect the result of isokinetic testing, resulting in erroneous
conclusions if not accounted for. Additionally, the previous use of VF to obtain increased
strength values has resulted in inconsistent findings. The purpose of this study was to examine
the effect of VF on concentric and eccentric knee extensor peak torque. Twenty-two sedentary,
college-aged male and female volunteers were assigned to either Group 1 (n = 11) or Group 2 (n
= 11) to either perform knee extensor concentric-eccentric (con-ecc) isokinetic testing with VF or
without VF (no-VF) using a crossover method. After a one-week rest, the two groups underwent
knee extensor con-ecc isokinetic testing using the alternative testing condition. Each test
consisted of five maximal knee extensor con-ecc isokinetic testing contractions at 60° per second
on the Cybex Norm system. The data indicated significant (p < 0.05) differences in the
concentric peak torque of Group 1, Group 2 and Combined Group following VF when compared
to no-VF. The eccentric peak torque of Group 1, Group 2 and Combined Group was found not to
be significantly different following VF when compared to no-VF. Further, no significant
interaction effect as a result of the different groups was found. Visual feedback of torque output
can improve maximum voluntary concentric contraction in isokinetic dynamometry, but not
maximum voluntary eccentric contraction. It is thus recommended that VF should be consistently
provided during isokinetic testing, since it can also be used to help detect and correct errors in
performance as well as derive reinforcement from correct performances.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:tut/oai:encore.tut.ac.za:d1001651 |
| Date | 01 September 2009 |
| Creators | Shaw, I, Shaw, BS, Cilliers, JF, Goon, DT |
| Publisher | African Journal for Physical, Health Education, Recreation and Dance |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | |
| Rights | African Journal for Physical, Health Education, Recreation and Dance |
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