Robb Kelly A, Perry Stephen D
Department of Kinesiology and Physical Education, Faculty of Science, Wilfrid Laurier University, 75 University Ave. West, Waterloo, ON N2L 3C5, Canada.
J Biomech. 2024 Mar;165:111999. doi: 10.1016/j.jbiomech.2024.111999. Epub 2024 Feb 15.
Foot posture describes the anatomical variance in an individual's overall foot shape, an important consideration in the provision of foot orthoses. Current orthoses designs could be optimized by considering the topographical organization of cutaneous mechanoreceptors. Currently, the effect of foot orthoses designs to enhance skin stimulation across different anatomical foot posture remains unknown. Thus, the purpose of this study was to investigate how foot posture variance modulates lower leg muscle activity when walking in non-textured orthoses and in textured orthoses which facilitates cutaneous mechanoreceptors under five different regions of the foot sole. Fifty-one (51) healthy young adults were subdivided by the Foot Posture Index and completed level walking trials wearing non-textured and textured foot orthoses. Surface and fine-wire electromyography (EMG) recorded muscle activity in 8 lower leg muscles. Statistically significant interactions were observed in each muscle's average EMG across textured location and Foot Posture Index score. For example, in pes cavus compared to pes planus feet, texture under the calcaneus generated greater aEMG of the tibialis anterior (44.9 mV ± 22.7 mV to 30.9 mV ± 11.4 mV) medial gastrocnemius (26.1 mV ± 16.7 mV to 17.5 mV ± 6.0 mV), and tibialis posterior (84.4 mV ± 77.1 mV to 64.4 mV ± 44.5 mV) muscles. This study demonstrates that lower leg muscle activity is modulated across the foot posture spectrum wearing non-textured and textured foot orthoses. Furthermore, in the development of new orthoses designs, specifically with texture, foot posture remains an important consideration when clinicians interpret EMG results and academics are designing new experimental protocols.
足部姿势描述了个体整体足部形状的解剖学差异，这是提供足部矫形器时的一个重要考虑因素。当前的矫形器设计可通过考虑皮肤机械感受器的地形组织来优化。目前，足部矫形器设计对增强不同解剖足部姿势下皮肤刺激的效果尚不清楚。因此，本研究的目的是调查在穿着无纹理矫形器和有纹理矫形器行走时，足部姿势差异如何调节小腿肌肉活动，其中有纹理矫形器可促进足底五个不同区域的皮肤机械感受器。51名健康的年轻成年人根据足部姿势指数进行了细分，并穿着无纹理和有纹理的足部矫形器完成了平地行走试验。表面肌电图和细针肌电图记录了8块小腿肌肉的肌肉活动。在每个肌肉的平均肌电图中，观察到了纹理位置和足部姿势指数评分之间具有统计学意义的相互作用。例如，与扁平足相比，高弓足在跟骨下方的纹理会使胫骨前肌（从44.9mV±22.7mV增加到30.9mV±11.4mV）、腓肠肌内侧头（从26.1mV±16.7mV增加到17.5mV±6.0mV）和胫骨后肌（从84.4mV±77.1mV增加到64.4mV±44.5mV）产生更大的肌电活动。本研究表明，在穿着无纹理和有纹理的足部矫形器时，小腿肌肉活动在整个足部姿势范围内受到调节。此外，在开发新的矫形器设计时，特别是带有纹理的设计，当临床医生解读肌电图结果以及学者设计新的实验方案时，足部姿势仍然是一个重要的考虑因素。
