MUSCLE-FIBER CONDUCTION-VELOCITY IN MOTOR UNITS OF THE HUMAN ANTERIOR TIBIAL MUSCLE - A NEW SIZE PRINCIPLE PARAMETER
MUSCLE-FIBER CONDUCTION-VELOCITY IN MOTOR UNITS OF THE HUMAN ANTERIOR TIBIAL MUSCLE - A NEW SIZE PRINCIPLE PARAMETER
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DOI：
10.1113/jphysiol.1987.sp016756
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发表时间：
1987-10-01
影响因子：
5.5
通讯作者：
ARENDTNIELSEN, L
中科院分区：
文献类型：
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作者：
ANDREASSEN, S;ARENDTNIELSEN, L
1.用双极针电极微刺激人胫前肌的单个运动神经轴突，引起抽搐收缩。所研究的刺激运动单位的群体对于肌肉是相当有代表性的。2.运动单元中纤维的状态速度计算为表面电极三极阵列中的电极间距（15 mm）与运动单元电位沿着电极阵列的传导延迟之间的比率。运动单元条件速度范围为2.6 - 5.3 m/s，平均值为3.7 m/s。3.运动单位的收缩特性通过平均踝关节周围产生的扭矩获得。扭转扭矩在小于10-3至16 × 10 - 3的范围内。10-3 Nm，平均值为5.7 × 10 - 5。10-3嗯。整个胫前肌的抽搐力矩约为5 N·m。上升时间为47-80 m/s，平均为61 m/s，半弛豫时间为40-78 ms，平均为60 ms。 各个运动单元的机械性能高度相关（上升时间和抽搐扭矩：r = -0.81;上升时间和半松弛时间：r = 0.75;抽搐扭矩和半松弛时间：r = -0.81）。5.运动单位传导速度与抽搐力矩（r = 0.87）、上升时间（r = -0.75）和半松弛时间（r = -0.66）高度相关。这表明，运动单位传导速度可以包括在家庭的相互关联的“大小原则参数”。
1. Twitch contractions were elicited in human anterior tibial muscle by intramuscular microstimulation of single motor axons with a bipolar needle electrode. The population of stimulated motor units studied was fairly representative for the muscle. 2. The condition velocity of the fibres in the motor unit was calculated as the ratio between the electrode separation (15 mm) in a tripolar array of surface electrodes and the conduction delay of the motor unit potential along the electrode array. The motor unit condition velocity ranged from 2.6 to 5.3 m/s with a mean of 3.7 m/s. 3. The contractile properties of the motor units were obtained by averaging the torque developed around the ankle joint. Twitch torques ranged from less than 10-3 to 16 .times. 10-3 N m, with a mean of 5.7 .times. 10-3 N m. The twitch torque of the whole anterior tibial muscle was approximately 5 N m. Rise times were 47-80 m/s with a mean of 61 m/s, and half-relaxation times were 40-78 ms with a mean of 60 ms. 4. The mechanical properties of individual motor units were highly correlated (rise time and twitch torque: r = -0.81; rise time and half-relaxation time: r = 0.75; twitch torque and half-relaxation time: r = -0.81). 5. The motor unit conduction velocity was highly correlated to twitch torque (r = 0.87), rise time (r = -0.75) and half-relaxation time (r = -0.66). This indicates that the motor unit conduction velocity can be included in the family of interrelated ''size principle parameters''.