RELATIVE DIFFERENCES IN STRENGTH AND POWER FROM SLOW TO FAST ISOKINETIC VELOCITIES MAY REFLECT DYNAPENIA

被引：23

作者：

Jenkins, Nathaniel D. M. ^{[1
]}

Housh, Terry J. ^{[1
]}

Palmer, Ty B. ^{[2
]}

Cochrane, Kristen C. ^{[1
]}

Bergstrom, Haley C. ^{[3
]}

Johnson, Glen O. ^{[1
]}

Schmidt, Richard J. ^{[1
]}

Cramer, Joel T. ^{[1
]}

机构：

[1] Univ Nebraska, Lincoln, NE 68583 USA

[2] Oklahoma State Univ, Stillwater, OK 74078 USA

[3] Univ Kentucky, Lexington, KY USA

来源：

MUSCLE & NERVE | 2015年 / 52卷 / 01期

关键词：

EMG; normalization; power-velocity; reliability; sarcopenia; torque-velocity; SKELETAL-MUSCLE MASS; HYDROXY-BETA-METHYLBUTYRATE; FORCE PRODUCTION CHARACTERISTICS; TORQUE DEVELOPMENT; FIBER-TYPE; CONTRACTILE PROPERTIES; ELECTROMYOGRAPHIC ACTIVITY; PROTEIN-METABOLISM; OLDER-ADULTS; ELDERLY-MEN;

D O I：

10.1002/mus.24505

中图分类号：

R74 [神经病学与精神病学];

学科分类号：

摘要：

Introduction: We compared absolute and normalized values for peak torque (PT), mean power (MP), rate of velocity development, and electromyography (EMG) amplitude during maximal isometric and concentric isokinetic leg extension muscle actions, as well as the % decrease in PT and % increase in MP from 1.05 to 3.14 rad.s(-1) in younger versus older men. Methods: Measurements were performed twice for reliability. Isokinetic measurements were normalized to the isometric muscle actions. Results: Absolute isometric PT, isokinetic PT and MP, and EMG amplitudes at 1.05 and 3.14 rad.s(-1) were greater in the younger men, although normalizing to isometric PT eliminated the age differences. The older men exhibited greater % decrease in PT (37.2% vs. 31.3%) and lower % increase in MP (87.6% vs. 126.4%) regardless of normalization. Conclusions: Normalization eliminated absolute differences in isokinetic strength and power, but the relative differences from slow to fast velocities may reflect dynapenia characterized by age-related decreases in fast-twitch fiber function.

引用

页码：120 / 130

页数：11

共 85 条

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