Department of Kinesiology and Physical Education, Faculty of Science, Wilfrid Laurier University, 75 University Ave., West Waterloo, ON, N2L 3C5, Canada.
Gait Posture. 2021 Mar;85:7-13. doi: 10.1016/j.gaitpost.2020.12.020. Epub 2021 Jan 19.
Previous literature on the transverse head of adductor hallucis (AddH-T) has largely focused on muscle morphology. This data provides insight into muscle architecture, yet fails to inform it's functional implication during walking. The role of the AddH-T, which runs parallel to the distal transverse metatarsal arch, has never been studied using fine-wire EMG during locomotion.
The purpose of this study is to explain a novel method of recording fine-wire EMG of the adductor hallucis muscle of the foot, and secondly, to report phasic AddH-T muscle activity during level walking on hard and soft surfaces.
Ultrasound-guided fine-wire EMG was recorded from the AddH-T of each foot, in ten asymptomatic young adults. Participants completed ten walking trials per experimental conditions (hard and soft surface). Ensemble averages were calculated from the time normalized linear-envelopes of each participant, and represented from 0 to 100 percent of the gait cycle.
Using the described ultrasound-guided fine-wire protocol, successful EMG signals were generated in 19 of 20 feet. When walking over hard or soft flooring, the AddH-T muscle has two bursts in EMG, occurring between 0-20 % and 50-65 % of the gait cycle. The magnitude of peak activity was often reduced at initial contact when walking over foam. 45 % of participants experienced a third burst in EMG activity at midstance, corresponding to 30-40 % of the gait cycle.
This study has successfully explained a novel method of recording finewire electromyography (EMG) of the adductor hallucis (transverse head) muscle of the foot. Results suggest that the AddH-T stabilizes the forefoot at initial contact and toeoff, while further anchoring the hallux during propulsion. These results provide preliminary insight into the functional role of the AddH-T during human locomotion.
先前关于内收肌横头（AddH-T）的文献主要集中在肌肉形态上。这些数据提供了对肌肉结构的深入了解，但未能说明其在行走过程中的功能意义。AddH-T 与远端横跖骨弓平行，其在运动过程中从未使用细钢丝肌电图进行过研究。
本研究的目的是解释一种记录足部内收肌横头（AddH-T）细钢丝肌电图的新方法，其次，报告在硬表面和软表面上水平行走时 AddH-T 肌肉的相位活动。
在 10 名无症状的年轻成年人的每只脚中，使用超声引导的细钢丝肌电图进行记录。参与者完成了每种实验条件（硬表面和软表面）下的 10 次行走试验。从每个参与者的时间归一化线性包络中计算出集合平均值，并代表步态周期的 0%至 100%。
使用描述的超声引导细钢丝协议，在 20 只脚中的 19 只脚上产生了成功的肌电图信号。当在硬地板或软地板上行走时，AddH-T 肌肉在步态周期的 0-20%和 50-65%之间有两个肌电图爆发。当在泡沫上行走时，初始接触时的峰值活动幅度通常会降低。45%的参与者在中足时经历了第三个肌电图活动爆发，对应于步态周期的 30-40%。
本研究成功地解释了一种记录足部内收肌（横头）肌的细钢丝肌电图（EMG）的新方法。结果表明，AddH-T 在初始接触和脚趾离地时稳定前脚，同时在推进过程中固定大脚趾。这些结果初步揭示了 AddH-T 在人类运动中的功能作用。
