Svenningsen Frederik Petri, Kaalund Emma, Christensen Tine Åkær, Helsinghoff Per Hedeager, Gregersen Nanett Yoo-Jin-Bruun, Kersting Uwe Gustav, Oliveira Anderson Souza
Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
Department of Materials and Production, Aalborg University, Aalborg, Denmark.
Hum Mov Sci. 2017 Dec;56(Pt B):20-28. doi: 10.1016/j.humov.2017.10.010. Epub 2017 Oct 31.
Load carriage can be harmful for workers, and alternative interventions to reduce back pain while walking and carrying loads are necessary. Unstable shoes have been used to improve balance and reduce back pain, but it is unknown whether walking wearing unstable shoes while carrying loads anteriorly causes excessive trunk extensors muscle activation. The aim of this study was to investigate the effects of different shoe types and anterior load carriage on gait kinematics and lumbar electromyographic (EMG) activity. Fourteen adults that predominantly walk or stand during the work day were asked to walk with and without carrying 10% of body mass anteriorly while wearing regular walking shoes (REG) and unstable shoes (MBT). The effects of shoe type, load carriage, and shoe × load interactions on the longissimus thoracis (LT) and iliocostalis lumborum (IC) EMG, stride duration, and stride frequency were assessed. MBT shoes induced a significant increase in LT (44.4 ± 35%) and IC EMG (33.0 ± 32%, p < .005), while load carriage increased LT (58.5 ± 41%) and IC EMG (55.1 ± 32%, p < .001). No significant shoe × load interaction was found (p>.05). However, walking wearing MBT shoes while carrying loads induced a 46 ± 40% higher EMG activity compared to walking wearing MBT shoes without load carriage. No effects of shoes or load carriage were found on stride duration and stride frequency. It was concluded that walking wearing MBT shoes and carrying 10% of total body mass induced greater activation of trunk extensors muscle compared to these factors in isolation, such a combination may not influence gait patterns.
背负重物可能对工人有害，因此需要采取替代干预措施来减轻行走和背负重物时的背痛。不稳定鞋已被用于改善平衡和减轻背痛，但在向前背负重物时穿着不稳定鞋行走是否会导致躯干伸肌过度激活尚不清楚。本研究的目的是调查不同鞋型和向前背负重物对步态运动学和腰部肌电图（EMG）活动的影响。要求14名在工作日主要行走或站立的成年人，在穿着普通步行鞋（REG）和不稳定鞋（MBT）时，分别进行背负和不背负10%体重的行走。评估了鞋型、背负重物以及鞋×负重交互作用对胸最长肌（LT）和腰髂肋肌（IC）肌电图、步幅持续时间和步频的影响。MBT鞋导致LT肌电图（44.4±35%）和IC肌电图显著增加（33.0±32%，p<0.005），而背负重物使LT肌电图（58.5±41%）和IC肌电图增加（55.1±32%，p<0.001）。未发现显著的鞋×负重交互作用（p>0.05）。然而，与不背负重物穿着MBT鞋行走相比，背负重物时穿着MBT鞋行走会使肌电图活动高出46±40%。未发现鞋或背负重物对步幅持续时间和步频有影响。得出的结论是，与单独的这些因素相比，穿着MBT鞋行走并背负10%的总体重会导致躯干伸肌更大程度的激活，这样的组合可能不会影响步态模式。
