Muscle Strength, Motor Units, and Aging

Introduction: The interrelationship between muscle strength, motor units, and aging is not well known. Methods: This investigation utilized the motor unit number index technique (MUNIX) to elucidate this relationship. Beforehand, an experiment was conducted to assess the absolute and relative reliability of the MUNIX technique. Statistical Analysis: The test-retest reliability of the technique was assessed by measures of relative reliability (coefficient of variation) and absolute reliability (limits of agreement and intraclass correlation). The interrelationship between muscle strength, motor units, and aging was determined by an analysis of covariance (ANCOVA) that tested heterogeneity of regression slopes (moderation analysis). Results: The test-retest analysis yielded moderate relative reliability and moderately-high absolute reliability. A positive linear relationship was found between MUNIX and strength in the elderly, but not in the young adults. Discussion: MUNIX is a reliable measure of motor unit number in a laboratory setting. Muscle weakness in the elderly appears to be, in part, moderated by the loss of functional motor units.

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Exercise Physiology-Research (Health Sciences and Professions)

Grantor dc:publisher

Ohio University

Year dc:date

2013

Author dc:creator

• Kaya, Ryan D.

Contributors dc:contributor

• Rana, Sharon

• Neurosciences
• Physiology
• Biomedical Research
• MUNIX
• MUSIX
• EMG
• Elderly
• Neuron

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1365769270

OAI identifier oai:identifier

oai:etd.ohiolink.edu:ohiou1365769270