Spaich Erika G, Arendt-Nielsen Lars, Andersen Ole K
Center for Sensory-Motor Interaction, Aalborg University, Fredrik Bajers Vej 7-D3, DK-9220 Aalborg, Denmark.
J Neurophysiol. 2004 Jan;91(1):258-66. doi: 10.1152/jn.00360.2003. Epub 2003 Sep 10.
The aim of this study was to investigate the modulation and topography of the nociceptive withdrawal reflex elicited by painful electrical stimulation of the foot sole during gait. Fifteen healthy volunteers participated in this study. Cutaneous electrical stimulation was delivered on five locations of the foot sole after heel-contact, during foot-flat, after heel-off, and during the mid-swing phase of the gait cycle during treadmill walking. Reflexes were recorded from muscles of the ipsilateral and contralateral legs. Furthermore, the kinematic responses in the sagittal plane of the ipsilateral ankle, knee, and hip joints were recorded. Reflexes in the distal muscles showed a site-dependent modulation. The largest responses in tibialis anterior were evoked at the arch of the foot and the smallest at the heel (P < 0.05). The largest soleus responses were also elicited at the arch of the foot (P < 0.04). The EMG responses in flexors and extensors of the knee and extensors of the contralateral leg were generally not dependent on the stimulation site. The response at the three joints showed site dependency, especially during the swing phase where maximal flexion was obtained by stimulation at the arch of the foot (P < 0.05). The withdrawal reflex was modulated during the gait cycle and presented distinctive characteristics for the different muscles studied. Minimal kinematic responses were observed during stance in contrast to swing phase. Modulation of the reflex probably ensures an appropriate withdrawal but primarily secures balance and continuity of movement.
本研究的目的是调查在步态期间通过对足底进行疼痛性电刺激所引发的伤害性退缩反射的调制情况和地形分布。15名健康志愿者参与了本研究。在跑步机行走过程中，在足跟触地后、足放平期间、足跟离地后以及步态周期的摆动中期，对足底的五个位置进行皮肤电刺激。记录同侧和对侧腿部肌肉的反射。此外，记录同侧踝关节、膝关节和髋关节矢状面的运动学反应。远端肌肉的反射表现出部位依赖性调制。胫骨前肌的最大反应在足弓处诱发，在足跟处最小（P<0.05）。比目鱼肌的最大反应也在足弓处诱发（P<0.04）。膝关节屈伸肌和对侧腿部伸肌的肌电图反应一般不依赖于刺激部位。三个关节处的反应表现出部位依赖性，尤其是在摆动期，此时在足弓处进行刺激可获得最大屈曲（P<0.05）。在步态周期中，退缩反射受到调制，并且在所研究的不同肌肉中呈现出独特的特征。与摆动期相比，在站立期观察到最小的运动学反应。反射的调制可能确保适当的退缩，但主要是确保运动的平衡和连续性。
