Responses in human motor unit activities during movement.

运动过程中人体运动单位活动的反应。

• 批准号: 03454537
• 负责人: KURATA Hiroshi
• 金额: $ 3.71万
• 依托单位: National Institute of Fitness and Sports
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03454537/
• 关键词: Motor unit; Recruitment; Threshold force; Firing frequency; Contractile properties; Movement loading

In single human motor units of abductor digiti minimi(ADM) muscle, there were motor units with maximal firing frequency at 80Hz, and with force threshold at 63% MVC.In motor units of ADM, extensor digitorum(ED), deltoid(D) and lateral vastus(LV) muscles, relationship between twitch contraction time, twitch peak tension and force threshold were examined. Force threshold was inversely proportional to contraction time except D muscle. Peak tension was proportional to force threshold except ED muscle. Relation between peak tension and contraction time was different in each muscle. In motor units of LV muscle, force threshold and its standard deviation tended to decrease following static force exersions. During isokinetic movement of knee and ankle joint at various load and angular velocities, recruitment order of motor units at shortening contractions widely changed from that at isometric contractions due to increase in load and shortening velocities. The results imply the selective recruitment of motor units depending on angular velocities. Also, the results suggest that there are two kinds of motor units recruited. One hand depends on the angular velocities, and the other hand depends on the joint angles. In characteristics of motor unis in ADM muscle following isometric and isotonic contractions, twitch contraction time tended to increase in fast type motor units, and it tended to decrease in slow type motor units. Recruitment and derecruitment order of motor units were different in the conditions of contractions. Due to the measurement of firing patterns of motor units in ADM and first dorsal interosseus(FDI) muscles during voluntary contractions, force control mechanisms were able to solve artificially by electrical nerve stimulations.

在人小指展肌(ADM)单个运动单位中，最大放电频率为80 Hz，力阈值为63%MVC。在ADM、趾伸肌(ED)、三角肌(D)和股外侧肌(LV)的运动单位中，研究了抽动收缩时间、抽动峰值张力与力阈值的关系。除D肌外，力阈值与收缩时间成反比。除ED肌外，峰值张力与用力阈值成正比。不同肌肉的峰值张力与收缩时间的关系不同。在LV肌运动单位中，静力作用后，力阈值及其标准差有减小的趋势。在不同负荷和角速度下膝关节和踝关节的等速运动中，由于负荷和缩短速度的增加，缩短收缩时运动单位的募集顺序与等长收缩时的募集顺序有很大的不同。结果表明，运动单位的选择性招募依赖于角速度。此外，结果还表明，有两种类型的运动单位被招募。一方面取决于角速度，另一方面取决于关节角度。在等长收缩和等张收缩后ADM肌的运动单位特征中，快型运动单位的抽动收缩时间有增加的趋势，慢型运动单位的抽动收缩时间有减少的趋势。在收缩条件下，运动单位的募集和去掉顺序不同。由于测量了自主收缩时ADM和第一背骨间肌(FDI)运动单位的放电模式，力控制机制能够通过电刺激人工解决。

项目成果

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小川义典等：“等张收缩时人体运动单位的活动——张力和活动模式——”第18届运动治疗研究会议论文集。

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Hiroyuki Tamaki 等人：“踝关节运动的角速度变化和人体腓肠肌外侧肌单个运动单位的活动模式”身体健康研究。

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Tamaki, H.等人：“在腓肠肌外侧肌中以不同角速度进行踝关节运动时，单个人体运动单位的募集顺序相反。”

和田 寿博 他: "短縮性および伸張性収縮時における単一運動単位の活動参加順序の変化" 体力科学.

Toshihiro Wada等人：“缩短和伸展收缩期间单个运动单位活动参与顺序的变化”身体健康科学。