青年女性递增负重行走时双侧足功能分化研究

Functional differentiation of bilateral feet in young women walking with increasing weight bearing

目的:探究支撑期步态功能性不对称规律及双侧足功能分化,深入了解人体运动补偿机制以及稳定控制特征,为预防单侧足踝损伤及康复治疗提供理论参考。方法:招募12名正常足型的青年女性受试者,通过三维动作捕捉及高频足底压力测试系统采集受试者在递增负重下[0%体重(body weight,BW)、10%BW、20%BW]以最适步速行走时优势足与非优势足的支撑期各阶段周期百分比、纵弓角度变化量、垂直地面反作用力及足底压力中心轨迹。运用双因素重复测量方差分析偏侧性(优势足、非优势足)和负重(0%BW、10%BW、20%BW)对足弓变化和步态参数的影响以及两者之间的交互作用。结果:(1)偏侧性和负重因素对足弓变化交互作用显著,对步态参数交互作用不显著。(2)与0%BW相比,非优势足负重20%BW缓冲阶段周期百分比增大(P<0.05),优势足负重20%BW缓冲阶段周期百分比减小(P<0.05),双侧足负重20%BW缓冲载荷率均增大(P<0.05),双侧足负重10%BW缓冲受力偏移均增大(P<0.05),双侧足负重10%BW、20%BW纵弓角度变化量增大(P<0.05),非优势足负重10%BW和20%BW蹬伸载荷率增大(P<0.05),优势足负重20%BW蹬伸水平斜率减小(P<0.05)。与10%BW相比,优势足负重20%BW缓冲阶段周期百分比减小(P<0.05),双侧足负重20%BW缓冲载荷率均增大(P<0.05),优势足负重20%BW缓冲受力偏移减小(P<0.05)。(3)与非优势足相比,负重10%BW和20%BW优势足缓冲载荷率减小(P<0.05),负重20%BW优势足纵弓角度变化量、蹬伸载荷率减小(P<0.05),负重0%BW优势足蹬伸水平斜率增大(P<0.05)。结论:负重行走会引起双侧足功能分化,无负重行走时优势足在水平方向上蹬伸效率更高,较小和较大负重时优势足在垂直方向上缓冲功能更佳,较大负重时非优势足在垂直方向上执行更充分的承重和蹬伸功能。提示行走时避免单侧足损伤的最大负荷,对于负重行走步态的研究不宜选取单足来代表和评价双足的功能和损伤风险。

Objective To explore the patterns of functional gait asymmetry during the support phase and the differentiation of bilateral foot functions,to gain insights into the human movement compensation mechanisms and stability control characteristics,so as to provide theoretical references for the prevention and rehabilitation treatment of unilateral foot and ankle injuries.Methods Twelve young females with normal feet were recruited,and the time percentage of each phase of the support period,the change of longitudinal arch angle,the vertical ground reaction force and the center of plantar pressure trajectory of the dominant and non-dominant feet were collected by using a three-dimensional motion capture and a high-frequency plantar pressure testing system when the subjects walked at the optimum speed with the incremental loading of weights[0%body weight(BW),10%BW and 20%BW].The effects of laterality(dominant foot,non-dominant foot)and load(0%BW,10%BW,20%BW)on arch changes and gait parameters,and the interactions between them,were analyzed using a two-wayrepeated-measures ANOVA.Results The factors of laterality and load interacted significantly on arch changes,but not on gait parameters.(2)Compared with 0%BW,the time percentage of the buffering phase of the nondominant feet with the load of 20%BW increased(P<0.05),while that of the dominant ones decreased(P<0.05),with an increase in the buffering load of both feet with the load of 20%BW(P<0.05)and the buffering force excursion of both feet with the load of 10%BW(P<0.05).Moreover,changes in longitudinal arch angle increased(P<0.05)with the load of 10%and 20%BW,the pedal extension load rate increased(P<0.05)with the above BW load in the non-dominant feet,and the horizontal slope of pedal extension decreased(P<0.05)with 20%BW load in the dominant feet.Compared with 10%BW,when the feed was loaded 20%BW,the time percentage in the buffering phase and the buffering force offset of the dominant feet decreased(P<0.05),while the buffering load of both feet increased(P<0.05).(3)Compared with the non-dominant feet,for the dominant feet,the buffering load rate at the load of 10%and 20%BW and changes in the longitudinal arch angle at the load of 20%BW decreased(P<0.05),while the horizontal slope of the pedal extension without load increased(P<0.05).Conclusion Walking with load induces function differentiation in bilateral feet.The dominant foot has more efficient horizontal extension without load and better buffering function in the vertical direction with loads,while the non-dominant feet perform a more adequate weight-bearing and extension function vertically with larger load.It is suggested that unilateral injury feet should not be given too much load,and it is inappropriate to select a single foot to represent and evaluate the function and injury risk of the double feet in loaded walking.