肌肉电刺激结合肌力训练对髌股疼痛综合征人群单腿下蹲动作生物力学特征的影响

The Effect of Electrical Muscle Stimulation and Strength Training on Mechanics during Single-Leg Squat in Patients with Patellofemoral Pain Syndrome

目的:髌股疼痛综合征(patellofemoral pain syndrome,PFPS)是一种常见的膝关节疼痛,运动疗法以及肌肉电刺激已被证明可以改善PFPS人群的疼痛及功能,但关于其是否能够改善下肢异常的生物力学特征仍存在争议。因此,研究旨在探讨6周的肌肉电刺激结合肌力训练以及单纯肌力训练对PFPS人群单腿下蹲动作生物力学和肌肉激活特征的影响。方法:招募46名PFPS受试者,随机分为肌肉电刺激训练(electric muscle stimulation,EMS)组和单纯肌力训练(muscle strength training,MST)组。通过疼痛视觉模拟评分表(visual analog scale,VAS)、膝前痛量表(anterior knee pain scale,AKPS)、红外动作捕捉系统、测力台以及表面肌电测试仪采集受试者干预前后单腿下蹲时的运动学、动力学以及表面肌电数据。采用双因素重复测量方差分析确定组别与时间对单腿下蹲时下肢生物力学特征的影响。结果:6周干预训练后,两组单腿下蹲时的VAS评分、髋关节最大内旋角、髋关节最大外展力矩、膝关节最大外展角、膝关节三维峰值力矩、髌股关节反作用力峰值显著降低,髋关节最大屈曲角、髋关节最大外旋力矩、臀肌及股内侧肌表面肌电活动显著提高。与MST组相比,EMS组在提高AKPS评分,降低髋关节最大内收角、膝关节最大屈曲角、膝关节最大外旋角、髌股关节应力峰值上更具优势。结论:EMS结合肌力训练有助于更好地纠正单腿下蹲时异常的髋膝运动模式,降低髌股关节负荷,进而改善PFPS人群疼痛及下肢功能。

Objective:Patellofemoral pain syndrome(PFPS)is a common causative factor of knee pain.The aim of this study was to investigate the lower limb mechanics and muscle activation during single-leg squats following 6-week training interventions of exercise and electrical muscle stimulation(EMS).Methods:Forty-six participants were recruited and randomly assigned into the muscle strength training(MST)group and EMS(combining EMS with strength training)group.Lower limb mechanics and muscle activation during single-leg squats were collected at before and after the 6-week intervention for each group by using infrared motion capture systems,force platform,and surface electromyography.Additionally,the visual analog score(VAS)and anterior knee pain scale(AKPS)were also recorded.Two-way(group by time)analysis of variance with repeated measures were applied to analyze the data.Results:After 6-week intervention,the VAS score,maximum hip internal rotation angle,maximum hip abduction moment,maximum knee abduction angle,peak knee three-dimensional moment,and peak patellofemoral joint reaction force during singleleg squat were all decreased;meanwhile,the maximum hip flexion angle,maximum hip external rotation moment,and muscle activation in gluteal and vastus medialis oblique were increased.Compared with the MST group,the EMS group demonstrated greater changes in increasing AKPS score and decreasing the maximum hip adduction angle,maximum knee flexion angle,maximum knee external rotation angle,and peak patellofemoral joint stress compared to the MST group following training.Conclusion:EMS training is beneficial for improving knee function and relieving pain in patients with PFPS compared to MST.EMS training is also contributed to altering hip and knee movement patterns during single-leg squats,consequently reducing the load on the patellofemoral joint.