title: Human neuromuscular structure and function in old age: A brief review.
abstract: Natural adult aging is associated with many functional impairments of the human neuromuscular system. One of the more observable alterations is the loss of contractile muscle mass, termed sarcopenia. The loss of muscle mass occurs primarily due to a progressive loss of viable motor units, and accompanying atrophy of remaining muscle fibers. Not only does the loss of muscle mass contribute to impaired function in old age, but alterations in fiber type and myosin heavy chain isoform expression also contribute to weaker, slower, and less powerful contracting muscles. This review will focus on motor unit loss associated with natural adult aging, age-related fatigability, and the age-related differences in strength across contractile muscle actions.
authors.affiliation: Human Performance Laboratory, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
authors.forename: Geoffrey A
authors.initials: GA
authors.lastname: Power
authors.affiliation: School of Kinesiology, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
authors.forename: Brian H
authors.initials: BH
authors.lastname: Dalton
authors.affiliation: Canadian Centre for Activity and Aging, School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, Ontario N6A 5B1, Canada; Department of Anatomy and Cell Biology, The University of Western Ontario, London, Ontario N6A 5C1, Canada.
authors.forename: Charles L
authors.initials: CL
authors.lastname: Rice
keywords: Aging; Eccentric; Force; Motor unit; Muscle atrophy; Power; Residual force enhancement; Sarcopenia; Velocity