自然行走对人体足底压力与下肢表面肌电信号影响的研究

目的 探究自然行走对正常人足底压力与下肢肌肉表面肌电信号(sEMG)的影响.方法 分别测量28例健康青年男性受试者在30 min平地自然行走前后足底压力与下肢肌肉的sEMG,得到行走前后峰值压强、冲量等足底压力参数及胫骨前肌、腓肠肌、股直肌与股二头肌的表面肌电时域参数积分肌电(iEMG)和频域参数平均功率频率(MPF),并检验峰值压强与身高、体质量的相关性.结果 平地自然行走开始时和30 min后,其左、右侧的峰值压强、冲量等各特征参数的差异均有统计学意义(均P＜0.05),不同参数的左、右侧差异分别体现在足底不同区域,而在跖骨区M3、M4、M5处各参数均表现出左侧大于右侧;行走前后左侧胫骨前肌、腓肠肌、骨直肌与股二头肌sEMG的iEMG均大于右侧;行走前后左侧胫骨前肌、腓肠肌的MPF大于右侧,其差异具有统计学意义(P＜0.05).30 min行走后右足脚趾区Toe2-5的峰值压强降低,其差异具有统计学意义(P＜0.05);各肌肉表面肌电iEMG无显著性变化,左侧股直肌的表面肌电信号的MPF显著性下降;峰值压强与身高、体质量均呈弱相关.结论 正常人自然行走中,足底压力和下肢表面肌电均具有左右侧的差异;30 min自然行走尚未导致足底压力出现明显疲劳状态的相应结果,因此自然行走30 min可维持步态的稳定性;30 min行走将导致左侧股直肌出现疲劳.

Effects of natural walking on human plantar pressure and surface electromyography of lower extremities

Objective To study the effects of natural walking on human plantar pressure and surface electromyogrphy (sEMG) of lower limbs.Methods 28 healthy male volunteers were enrolled,and their plantar pressure and surface electromyogrphy related parameters were measured before and after 30 min natural walking.These parameters not only include plantar peak pressure and peak impulse,but also include time domain parameter (integral electromyogrphy,iEMG) and frequency domain parameter (mean power frequency,MPF) of tibial anterior muscle,gastrocnemius,femoral rectus,and biceps femoris muscle.The correlations between peak pressure and height as well as weight were analyzed.Results The feature parameters showed significant difference between left and right foot before and after 30 min natural walking (all P＜0.05).The differences of peak pressure and peak impulse values between left and right limb were found in different plantar areas.In the metatarsal areas M3,M4 and M5,the pressure parameters of left side were larger than those of right side (all P＜0.05).The values of iEMG and sEMG of left limb were larger than those of right side in tibialis anterior,gastrocnemius,rectus femoris and biceps femoris (all P＜ 0.05).The MPF values of sEMG of left limb were larger than those of right side in tibialis anterior and gastrocnemius (all P＜0.05).After 30 min natural walking,the peak pressures in right toe2-5 areas were decreased (all P＜0.05),the differences of iEMG of sEMG in all muscles were not significantly,and the MPF value of sEMG in left rectus femoris was decreased.Weak correlations were observed between peak pressure and height as well as weight.Conclusions The differences of left and right lower limbs were found in plantar pressure and sEMG values during natural walking.The results showed that 30 min natural walking did not cause significant stress-related fatigue in plantar areas.Therefore,the stability of gait can be maintained for a 30 min natural walking.However,that may lead to fatigue of the femoris rectus in the left limb.