Murley George S, Menz Hylton B, Landorf Karl B
Department of Podiatry, Faculty of Health Sciences, La Trobe University, Bundoora 3086, Australia; Lower Extremity and Gait Studies Program, Faculty of Health Sciences, La Trobe University, Bundoora 3086, Australia.
Department of Podiatry, Faculty of Health Sciences, La Trobe University, Bundoora 3086, Australia; Lower Extremity and Gait Studies Program, Faculty of Health Sciences, La Trobe University, Bundoora 3086, Australia.
Gait Posture. 2014 Apr;39(4):1080-5. doi: 10.1016/j.gaitpost.2014.01.018. Epub 2014 Feb 6.
The effect of walking speed on superficial lower limb muscles, such as tibialis anterior and triceps surae, is well established. However, there are no published data available for tibialis posterior - a muscle that plays an important role in controlling foot motion. The purpose of this study was to characterise the electromyographic timing and amplitude of selected lower limb muscles across five walking speeds. Thirty young adults were instructed to walk barefoot while electromyographic activity was recorded from tibialis posterior and peroneus longus via intramuscular electrodes, and medial gastrocnemius and tibialis anterior via surface electrodes. At faster walking speeds, peak electromyographic amplitude increased systematically during the contact and midstance/propulsion phases. Changes in the time of peak amplitude were also observed for tibialis posterior, tibialis anterior and peroneus longus activity; however, these were muscle and phase specific. During contact phase, peak electromyographic amplitude for tibialis posterior and peroneus longus was similar across very slow to slow walking speeds. During midstance/propulsion phase, peak electromyographic amplitude for tibialis posterior and medial gastrocnemius was similar across very slow to slow walking speeds. These findings may reflect a relatively higher than expected demand for peroneus longus and tibialis posterior to assist with medio-lateral foot stability at very slow speeds. Similarly, peak amplitude of medial gastrocnemius was also relatively unchanged at the very slow speed, presumably to compensate for the reduced forward momentum. The data presented in this study may serve as a reference for comparing similarly matched participants with foot deformity and/or pathological gait.
行走速度对下肢表浅肌肉（如胫骨前肌和腓肠肌）的影响已得到充分证实。然而，关于胫骨后肌（在控制足部运动中起重要作用的肌肉），尚无公开数据。本研究的目的是描述选定的下肢肌肉在五种行走速度下的肌电图时间和幅度特征。30名年轻成年人被要求赤脚行走，同时通过肌内电极记录胫骨后肌和腓骨长肌的肌电活动，通过表面电极记录腓肠肌内侧头和胫骨前肌的肌电活动。在较快的行走速度下，肌电图峰值幅度在接触期和支撑中期/推进期有系统性增加。胫骨后肌、胫骨前肌和腓骨长肌活动的峰值幅度时间也有变化；然而，这些变化是肌肉和阶段特异性的。在接触期，从极慢到慢速行走时，胫骨后肌和腓骨长肌的肌电图峰值幅度相似。在支撑中期/推进期，从极慢到慢速行走时，胫骨后肌和腓肠肌内侧头的肌电图峰值幅度相似。这些发现可能反映出在极慢速度下，腓骨长肌和胫骨后肌在协助足部内外侧稳定性方面的需求相对高于预期。同样，在极慢速度下，腓肠肌内侧头的峰值幅度也相对不变，大概是为了补偿向前动量的减少。本研究中呈现的数据可作为比较足部畸形和/或病理性步态的匹配参与者的参考。
