MOTOR UNIT NUMBER ESTIMATION AND NEUROMUSCULAR FIDELITY IN 3 STAGES OF SARCOPENIA

作者：Gilmore Kevin J; Morat Tobias; Doherty Timothy J; Rice Charles L^*

来源：Muscle & Nerve, 2017, 55(5): 676-684.

DOI：10.1002/mus.25394

• aging
• electromyography
• human
• muscle
• motor neuron
• strength

Introduction: Loss of motor units (MUs) and alterations in MU properties are major factors in development of sarcopenia. The purpose of this study was to compare MU properties among 3 groups categorized as either pre-sarcopenic (n=7), sarcopenic (n=7), or severely sarcopenic (n=5), all with similarly aged subjects (75-82 years). Methods: Using decomposition-enhanced quantitative electromyography, MU number estimates and neuromuscular stability measures of near-fiber (NF) jitter and jiggle were derived in addition to contractile properties of ankle dorsiflexors. Results: MU number estimates were similar across groups; however, maximal voluntary strength in the severe sarcopenia group was 27% and 37% less than the sarcopenic and pre-sarcopenic groups, respectively. Moreover, NF jiggle was 31% greater in the severe group compared with pre-sarcopenia, NF jitter was 43% greater in the severe group compared with the pre-sarcopenic group. Conclusion: Unlike MU number estimates, strength and MU stability differed across groups and related to degree of sarcopenia.

• 出版日期2017-5