Date of Award

Spring 5-1-2003

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Life Sciences

First Advisor

Jeffrey E. Edwards

Second Advisor

Mitchell L. Cordova

Third Advisor

J. P. Babington

Abstract

Context: Muscle fatigue has been implicated as a factor in the cause of exercise associated muscle cramping. In an electrically induced muscle cramp, threshold frequency (TF) is the frequency of stimulation at which the cramp originates. Therefore, the TF of a fatigued muscle should shift from a previously established baseline. Objective: To determine the effect of local muscle fatigue on TF of electrically induced muscle cramp. Design: A 2 X 2 repeated measures design was used for this study. The independent variables were test (pre- and post-) and condition (control and fatigue). The dependent variable was TF of an electrically induced cramp of the flexor hallucis brevis. Setting: The study was performed in Indiana State University's Sports Injury Research Laboratory. Subjects: Sixteen healthy subjects were recruited and counterbalanced assigned to testing order. Intervention: To induce a fatigued state, subjects performed 5 bouts of great toe curls at 60% 1-RM to failure with 1 min rest between bouts. Main Outcome Measures: Pre-control, post-control, and pre-fatigue TF will be greater than post-fatigue TF. Results: Of 16 subjects, 5 were excluded due to the fatigue criteria not being achieved post-exercise. A condition (fatigue/control) X test (pre/post) repeated measures ANOV A revealed a test by condition interaction for TF (F 1, 10 = 37.655, P < 0.001). Simple main effects testing showed post-fatigue TF was significantly greater than pre-fatigue TF (t10 = -6.745, P < 0.001) Conclusion: Local muscle fatigue significantly increases the TF of an electrically induced muscle cramp.

Download

Share

COinS