Emborg Jonas, Spaich Erika G, Andersen Ole K
Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 7 D-3, 9220 Aalborg, Denmark.
Med Biol Eng Comput. 2009 Jan;47(1):29-39. doi: 10.1007/s11517-008-0396-x. Epub 2008 Oct 1.
The objective of this study was to investigate the modulation of the nociceptive withdrawal reflex during gait measured using Force Sensitive Resistors (FSR). Electrical stimulation was delivered to four locations on the sole of the foot at three different time points between heel-off and toe-off. Peak force changes were measured by FSRs attached to the big toe, distal to the first and fourth metatarsophalangeal joints, and the medial process of the calcaneus on both feet. Force changes were assessed in five gait sub-phases. The painful stimulation led to increased ipsilateral unloading (10 +/- 1 N) and contralateral loading (12 +/- 1 N), which were dependent on stimulation site and phase. In contrast, the hallux of the ipsilateral foot plantar flexed, thus facilitating the push-off. The highest degree of plantar flexion (23 +/- 10 N; range, 8-44 N) was seen in the second double support phase following the stimulation. Site and phase modulation of the reflex were detected in the force signals from all selected anatomical landmarks. In the kinematic responses, both site and phase modulation were observed. For stimulations near toe-off, withdrawal was primarily accomplished by ankle dorsiflexion, while the strategy for stimulations at heel-off was flexion of the knee and hip joints.
本研究的目的是使用力敏电阻（FSR）来研究步态过程中伤害性退缩反射的调制情况。在足跟离地到足趾离地之间的三个不同时间点，对足底的四个位置进行电刺激。通过附着在双脚大脚趾、第一和第四跖趾关节远端以及跟骨内侧突起处的FSR测量峰值力变化。在五个步态子阶段评估力的变化。疼痛刺激导致同侧卸载增加（10±1 N）和对侧加载增加（12±1 N），这取决于刺激部位和阶段。相比之下，同侧足的拇趾跖屈，从而有助于蹬离动作。在刺激后的第二个双支撑阶段观察到最高程度的跖屈（23±10 N；范围为8 - 44 N）。在所有选定解剖标志点的力信号中检测到反射的部位和阶段调制。在运动学反应中，观察到了部位和阶段调制。对于接近足趾离地的刺激，退缩主要通过踝关节背屈完成，而足跟离地时刺激的策略是膝关节和髋关节屈曲。
