Maximum shortening speed of motor units of various types in cat lumbrical muscles.
Maximum shortening speed of motor units of various types in cat lumbrical muscles.
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猫蚓状肌中各类运动单位的最大缩短速度。
DOI：
10.1152/jn.1993.69.2.442
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发表时间：
1993
影响因子：
2.5
通讯作者：
Hunt,CC
中科院分区：
文献类型：
--
作者：
Petit,J;Chua,M;Hunt,CC
1. 在已确定类型的单个运动单位的最大强直收缩期间，研究了猫浅表蚓状肌的等张缩短。对于每个运动单位，最大收缩速度 Vmax 是通过将施加的张力和收缩速度之间的双曲线关系外推至零来确定的。 2.运动单位缩短的最大速度形成一个连续体，观察到快速易疲劳运动单位的速度最高，而慢速运动单位的速度最低。 3.平均而言，最大缩短速度随着运动单位产生的强直张力而增加。 4. 在等长抽搐收缩时间小于 35 ms 的运动单位中，这些时间与 Vmax 呈显着的负相关。收缩时间逐渐延长与 Vmax 的微小变化相关。 5. 讨论了这些发现对运动单位募集过程中肌肉缩短速度的影响。
1. Isotonic shortening of cat superficial lumbrical muscles was studied during maximal tetanic contractions of single motor units of identified types. For each motor unit, the maximal speed of contraction, Vmax, was determined by extrapolating to zero the hyperbolic relation between applied tension and speed of shortening. 2. The maximal speeds of shortening of motor units formed a continuum with the highest velocities observed for the fast fatigable motor units and the lowest for the slow motor units. 3. On average, the maximum speed of shortening increased with the tetanic tension developed by the motor units. 4. In motor units with isometric twitch contraction times less than 35 ms, these times showed a significant inverse correlation with Vmax. Progressively longer contraction times were associated with rather small changes in Vmax. 5. The implications of these findings on the speed of muscle shortening during motor-unit recruitment are discussed.