Proprioceptive modulation of hip flexor activity during the swing phase of locomotion in decerebrate cats
Proprioceptive modulation of hip flexor activity during the swing phase of locomotion in decerebrate cats
复制标题
DOI：
10.1152/jn.2001.86.3.1321
复制
发表时间：
2001-09-01
影响因子：
2.5
通讯作者：
Pearson, KG
中科院分区：
文献类型：
--
作者：
Lam, T;Pearson, KG
本研究在去大脑猫行走的摆动阶段，观察了髋屈肌本体感觉输入对髋屈肌活动的影响。其中一条后肢部分失神经，以去除皮肤输入和大部分其他后肢肌肉的传入输入。对髋关节运动的干扰是通过1)手动阻力或辅助摆动，或2)使用阻止髋关节屈曲但允许腿部伸展的装置来抵抗髋关节屈曲。肌电记录来自髂腰肌(IP)、缝匠肌和腓肠肌内侧。当人工辅助髋关节进入屈曲状态时，髋屈肌爆裂活动减少。相反，当在摆动过程中手动抵抗或机械阻止髋屈肌时，髋屈肌活动的持续时间和幅度都会增加。我们还发现来自单个髋屈肌的传入物质在调节屈肌爆发活动中所起的作用具有一定的特异性。如果IP肌从其附着处分离，对阻断屈曲的反应几乎没有变化。通过拉伸肌肉来特异性激活IP传入纤维也不会对屈肌活动产生很大影响。另一方面，如果缝匠肌神经的传导被阻断，对髋关节屈曲的阻断反应就会减弱。屈肌爆发持续时间的增加仍然存在，但这种增加一直低于缝匠肌神经完整时的观察结果。根据这些结果，我们认为在挥杆过程中，来自髋屈肌传入的反馈，特别是来自缝匠肌的反馈，增强了屈肌的活动。此外，如果延迟对侧后肢屈肌活动的开始，阻断髋关节屈曲往往会导致同侧屈肌活动长时间延长，进一步揭示屈肌传入反馈对屈肌活动的强化作用。如果缝匠肌神经的传导被阻断，这种影响就看不到了。综上所述，我们发现在运动过程中髋屈肌的活动可以通过改变髋屈肌的本体感觉反馈而得到强烈的调节。
This study examined the influence of proprioceptive input from hip flexor muscles on the activity in hip flexors during the swing phase of walking in the decerebrate cat. One hindlimb was partially denervated to remove cutaneous input and afferent input from most other hindlimb muscles. Perturbations to hip movement were applied either by 1) manual resistance or assistance to swing or by 2) resistance to hip flexion using a device that blocked hip flexion but allowed leg extension. Electromyographic recordings were made from the iliopsoas (IP), sartorius, and medial gastrocnemius muscles. When the hip was manually assisted into flexion, there was a reduction in hip flexor burst activity. Conversely, when hip flexion was manually resisted or mechanically blocked during swing, the duration and amplitude of hip flexor activity was increased. We also found some specificity in the role of afferents from individual hip flexor muscles in the modulation of flexor burst activity. If the IP muscle was detached from its insertion, little change in the response to blocking flexion was observed. Specific activation of IP afferent fibers by stretching the muscle also did not greatly affect flexor activity. On the other hand, if conduction in the sartorius nerves was blocked, there was a diminished response to blocking hip flexion. The increase in duration of the flexor bursts still occurred, but this increase was consistently lower than that observed when the sartorius nerves were intact. From these results we propose that during swing, feedback from hip flexor muscle afferents, particularly those from the sartorius muscles, enhances flexor activity. In addition, if we delayed the onset of flexor activity in the contralateral hindlimb, blocking hip flexion often resulted in the prolongation of ipsilateral flexor activity for long, periods of time, further revealing the reinforcing effects of flexor afferent feedback on flexor activity. This effect was not seen if conduction in the sartorius nerves was blocked. In conclusion, we have found that hip flexor activity during locomotion can be strongly modulated by modifying proprioceptive feedback from the hip flexor muscles.