Voigt M, Dyhre-Poulsen P, Simonsen E B
Center for Sensory-Motor Interaction, Aalborg University, Denmark.
Acta Physiol Scand. 1998 Jun;163(2):181-94. doi: 10.1046/j.1365-201X.1998.00351.x.
To gain insight into central and peripheral reflex control mechanisms in moving humans we have investigated short latency stretch reflex activity in m. triceps surae during two legged hopping. The objectives were: (1) to compare movement induced short latency stretch reflexes in soleus and medial gastrocnemius (MG) muscles, (2) to determine the relationship between the size of these reflexes and the muscle spindle stretch velocities, and (3) to compare the size of the movement induced short latency stretch reflexes and the H-reflexes simultaneously. Six well-trained healthy male subjects participated and they hopped at three different work rates. Surface electromyogram (EMG) and H-reflexes were recorded during hopping. Muscle spindle length changes were estimated as the difference between estimated origin-to-insertion length changes and tendon length changes. The important findings were that during hopping: (1) movement induced short latency stretch reflexes were observed consistently in soleus, (2) the EMG amplitude of this stretch reflex was negatively correlated with the estimated peak muscle spindle stretch velocity (rs = -0.52, P < 0.02), and (3) the amplitude of the soleus H-reflex at touchdown did not change in parallel with the stretch reflex. The negative correlation observed between the stretch reflex and the estimated peak muscle spindle stretch velocity in soleus is opposite to the basic velocity sensitive behaviour of stretch reflexes mechanically elicited during resting conditions. Possible control mechanisms are discussed. Additionally, muscle spindle length changes estimated from changes in the skeletal movements (joint angles) should be inferred cautiously because of tendon compliance, especially at high tendon forces.
为深入了解运动中的人体中枢和外周反射控制机制，我们研究了在双腿跳跃过程中比目鱼肌的短潜伏期牵张反射活动。目的如下：（1）比较运动诱发的比目鱼肌和腓肠肌内侧（MG）的短潜伏期牵张反射；（2）确定这些反射的大小与肌梭牵张速度之间的关系；（3）同时比较运动诱发的短潜伏期牵张反射和H反射的大小。六名训练有素的健康男性受试者参与了研究，他们以三种不同的工作速率进行跳跃。在跳跃过程中记录表面肌电图（EMG）和H反射。肌梭长度变化通过估计的起止点长度变化与肌腱长度变化之间的差异来估算。重要发现如下：在跳跃过程中，（1）比目鱼肌持续观察到运动诱发的短潜伏期牵张反射；（2）该牵张反射的EMG幅度与估计的肌梭峰值牵张速度呈负相关（rs = -0.52，P < 0.02）；（3）着地时比目鱼肌H反射的幅度与牵张反射并非同步变化。比目鱼肌牵张反射与估计的肌梭峰值牵张速度之间观察到的负相关与静息状态下机械诱发的牵张反射的基本速度敏感行为相反。文中讨论了可能的控制机制。此外，由于肌腱的顺应性，尤其是在高肌腱力情况下，从骨骼运动（关节角度）变化估算的肌梭长度变化应谨慎推断。
