Laboratory of Neurophysiology, Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
Muscle Nerve. 2010 Jul;42(1):78-87. doi: 10.1002/mus.21599.
To investigate the functional significance of force fluctuations during voluntary contraction with a select muscle group, we examined the association between force fluctuations during voluntary contraction with plantar flexor muscles and postural sway during quiet standing in 20 young and 20 elderly adults. Young and elderly subjects maintained a quiet standing position on a force platform. They also performed a force-matching task with unilateral isometric plantar flexion. A positive correlation was found in young and elderly adults between the coefficient of variation (CV) of center of pressure during quiet standing and the CV of force during plantar flexion only at contraction intensities of < or =5% maximum voluntary contraction that corresponded to muscle activity during quiet standing. The electromyogram power in the medial gastrocnemius was greater in the elderly than in young adults by approximately 10 Hz during quiet standing and at low contraction intensities during plantar flexion. Fluctuations in motor output during low-intensity plantar flexion were associated with postural sway during quiet standing in both young and elderly adults.
为了研究特定肌肉群在自愿收缩过程中力波动的功能意义，我们检测了 20 名年轻和 20 名老年成年人在自愿收缩时足底屈肌的力波动与安静站立时姿势摆动之间的相关性。年轻和老年受试者在力平台上保持安静站立姿势。他们还执行了单侧等长足底屈曲的力匹配任务。在年轻和老年人中，静息站立时的中心压力变异系数（CV）与足底屈曲时的力 CV 之间存在正相关，仅在 <或= 5%最大自愿收缩的收缩强度下存在相关，这与静息站立时的肌肉活动相对应。在静息站立和足底屈曲的低收缩强度时，老年组的比目鱼肌肌电图功率比年轻组高约 10 Hz。在低强度的足底屈曲时，运动输出的波动与年轻和老年成年人在安静站立时的姿势摆动有关。
