The purpose of this study was to compare the use of intramuscular (iEMG) and surface (sEMG) electromyography electrodes to record flexor hallucis longus (FHL) muscle activity during walking, and describe the role of the FHL. Muscle activity was recorded in 12 participants using sEMG and iEMG during treadmill and overground walking. Inter-tester reliability for visual detection of onset and offset of muscle activity was high (ICC = 1.00). During the loading period, the number of bursts of muscle activity was statistically significantly greater using iEMG compared to sEMG when treadmill walking (p = 0.016), and the duration of muscle activity was significantly greater for iEMG (p = 0.01) on both walking surfaces. There were no differences for peak and mean root mean squared (p ≥ 0.07). The FHL activity observed during the loading period (heel strike to forefoot strike) supports the function of the FHL to act as a dynamic ankle stabiliser of the rearfoot, as well as contributing to propulsion during the latter part of stance. The choice of electrodes to detect FHL activity should be dependent on whether the loading and propulsive periods are of interest, and whether treadmill or overground walking will be examined.

本研究的目的是比较使用肌内 (iEMG) 和表面 (sEMG) 肌电图电极记录行走过程中拇长屈肌 (FHL) 的肌肉活动，并描述 FHL 的作用。在跑步机和地上行走期间使用 sEMG 和 iEMG 记录了 12 名参与者的肌肉活动。肌肉活动开始和偏移的视觉检测的测试者间可靠性很高（ICC = 1.00）。在加载期间，使用 iEMG 的肌肉活动爆发次数在统计学上显着高于跑步机行走时的 sEMG（p = 0.016），并且 iEMG 的肌肉活动持续时间（p = 0.01）在两个行走表面上都显着更长. 峰值和平均均方根没有差异（p ≥ 0.07）。在负重期间观察到的 FHL 活动（脚跟撞击到前足撞击）支持 FHL 作为后足动态踝关节稳定器的功能，并有助于在站立后期提供推进力。用于检测 FHL 活动的电极的选择应取决于是否对负载和推进周期感兴趣，以及是否要检查跑步机或地上行走。