Power Geoffrey A, Dalton Brian H, Rice Charles L
Human Performance Laboratory, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
School of Kinesiology, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
J Sport Health Sci. 2013 Dec;2(4):215-226. doi: 10.1016/j.jshs.2013.07.001.
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.
自然衰老与人类神经肌肉系统的许多功能障碍有关。其中一个较为明显的变化是收缩性肌肉质量的丧失，即肌肉减少症。肌肉质量的丧失主要是由于存活运动单位的逐渐丧失以及剩余肌纤维的萎缩。肌肉质量的丧失不仅导致老年时功能受损，而且纤维类型和肌球蛋白重链同工型表达的改变也会导致肌肉收缩更弱、更慢且力量更小。本综述将重点关注与自然衰老相关的运动单位丧失、与年龄相关的疲劳性以及收缩性肌肉活动中与年龄相关的力量差异。
