Naomi Laird

Publication Date

1994

Document Type

Dissertation/Thesis

First Advisor

Ball, Thomas E.

Degree Name

M.S. Ed. (Master of Education)

Legacy Department

Department of Physical Education

LCSH

Knee--Muscles--Testing; Fatigue--Testing; Muscle strength--Testing

Abstract

Research focused on identifying risk factors of injury has included the flexor/extensor ratio. Studies have yet to examine the effects of fatigue on this ratio. The purpose of the present study was to compare the knee flexor/extensor ratio before and after a fatiguing task to determine if the ratio is altered. Twenty- seven (N=27, male=20 and female =7) healthy high school varsity and collegiate athletes (ages 15-24 yrs, mean 19.2 yrs.) participated in the study. Individuals' dominant leg knee flexor and extensor muscles were tested with the Cybex 340 dynamometer at speeds of 60, 180 and 300°/second. The flexor/extensor ratio was calculated by the Cybex 340 computer. Subjects were then fatigued by having them run against a resistance and immediately post-tested on the Cybex 340. A significance level of 0.05 was used for all hypothesis testing. A 2X3 ANOVA with repeated measures was used to compare pre-test verses post-test values. ANOVA procedures were used to compare effects of speed within subjects. The analysis of variance revealed a significant difference between pre- and post-test (p= 0.027), indicating fatigue does have an effect on the flexor/extensor ratio. The dependent t-test reveals a significant change in the flexor/extensor ratio only at 60°/second. The ANOVA showed a significant difference (p<0.05) in ratios when comparing effects of speed. The flexor/extensor ratio increased as the speed increased. The findings of the present study indicate that fatigue does have an effect on the flexor\extensor ratio. However, there was a great individual variance between subjects.

Comments

Includes bibliographical references (pages [20]-22)

Extent

37 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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