Electronic Thesis and Dissertation Repository

Degree

Master of Science

Program

Kinesiology

Supervisor

Dr. Charles L. Rice

Abstract

PURPOSE: To evaluate anconeus motor unit firing rate (MUFR) as a function of time to task failure (TTF) during maximal velocity elbow extensions at a moderately heavy load. METHODS: Two fine-wire intramuscular electrode pairs were inserted into the anconeus to record MUFR in twelve male participants (25±3y). Individual MUs were tracked throughout a three-stage dynamic elbow extension fatigue protocol. Mean MUFR were calculated for the following time ranges: 0-15%, 45-60%, and 85-100% TTF. RESULTS: Following the fatigue task, with a mean TTF of 83s, peak power decreased 64% compared to baseline. Data from 20 anconeus MUs showed changes in MUFR from ~36 Hz (0-15% TTF) to ~28 Hz (45-60% TTF) to ~23 Hz (85-100% TTF). CONCLUSION: During high-intensity maximal velocity dynamic contractions, anconeus firing rates decreased substantially. The relative decrease in MUFR after this task is in accordance with that reported for sustained high-intensity isometric tasks in other muscles.

BCowlingCertificateofExamination.pdf (13 kB)
Certificate of Examination


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