Grey Michael J, van Doornik Johan, Sinkjaer Thomas
Center for Sensory-Motor Interaction, Aalborg University, Fredrik Bajersvej 7-D3, DK-9220, Aalborg Øst, Denmark.
Eur J Neurosci. 2002 Nov;16(10):2001-7. doi: 10.1046/j.1460-9568.2002.02250.x.
Numerous animal and human studies have shown that afferent information from the periphery contributes to the control of walking. In particular, recent studies have consistently shown that load receptor input is an important element of the locomotion control mechanism. The objective of this study was to investigate the contribution of load receptor feedback to the compensatory stretch reflex response. We examined the contribution of load receptor feedback to the magnitude of the short and medium latency components of the ankle plantar flexor stretch reflex responses following an unexpected dorsiflexion perturbation during human walking. Three body load conditions were investigated: normal body load, a 30% increase in body load, and a 30% decrease in body load. Healthy subjects walked on a treadmill at approximately 3.6 km/h with the left ankle attached to a portable stretching device. Dorsiflexion perturbations (8 degrees; 350-425 degrees/s) were generated during the late stance phase of gate (approximately 400 ms following heel contact). Electromyographic activity was recorded from the soleus, tibialis anterior, medial gastrocnemius, rectus femoris, and biceps femoris muscles using bipolar surface electrodes. Stretch reflex responses were observed in the soleus and gastrocnemius muscles for all of the body load conditions; however, increasing or decreasing the body load did not affect the timing and magnitude of the responses. This study provides evidence that load receptor input does not contribute strongly to the corrective response of the stretch reflex in the plantar flexor muscles during walking.
大量的动物和人体研究表明，来自外周的传入信息有助于步行控制。特别是，最近的研究一致表明，负荷感受器输入是运动控制机制的一个重要组成部分。本研究的目的是调查负荷感受器反馈对代偿性牵张反射反应的贡献。我们研究了在人类步行过程中意外背屈扰动后，负荷感受器反馈对踝跖屈肌牵张反射反应的短潜伏期和中潜伏期成分大小的贡献。研究了三种身体负荷条件：正常身体负荷、身体负荷增加30%和身体负荷减少30%。健康受试者在跑步机上以约3.6公里/小时的速度行走，左脚踝连接到一个便携式拉伸装置上。在步态的后期支撑阶段（脚跟接触后约400毫秒）产生背屈扰动（8度；350 - 425度/秒）。使用双极表面电极记录比目鱼肌、胫骨前肌、腓肠肌内侧头、股直肌和股二头肌的肌电图活动。在所有身体负荷条件下，比目鱼肌和腓肠肌均观察到牵张反射反应；然而，增加或减少身体负荷并不影响反应的时间和大小。本研究提供了证据，表明在步行过程中，负荷感受器输入对跖屈肌牵张反射的纠正反应贡献不大。
