Clément Julien, Hagemeister Nicola, Aissaoui Rachid, de Guise Jacques A
École de technologie supérieure (ÉTS), Montréal, QC, Canada; Laboratoire de recherche en Imagerie et Orthopédie, Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Hôpital Notre-Dame, Montréal, QC, Canada.
Gait Posture. 2014;40(1):94-100. doi: 10.1016/j.gaitpost.2014.02.016. Epub 2014 Mar 10.
Numerous studies have described 3D kinematics, 3D kinetics and electromyography (EMG) of the lower limbs during quasi-static or dynamic squatting activities. One study compared these two squatting conditions but only at low speed on healthy subjects, and provided no information on kinetics and EMG of the lower limbs. The purpose of the present study was to contrast simultaneous recordings of 3D kinematics, 3D kinetics and EMG of the lower limbs during quasi-stat ic and fast-dynamic squats in healthy and pathological subjects. Ten subjects were recruited: five healthy and five osteoarthritis subjects. A motion-capture system, force plate, and surface electrodes respectively recorded 3D kinematics, 3D kinetics and EMG of the lower limbs. Each subject performed a quasi-static squat and several fast-dynamic squats from 0° to 70° of knee flexion. The two squatting conditions were compared for positions where quasi-static and fast-dynamic knee flexion-extension angles were similar. Mean differences between quasi-static and fast-dynamic squats were 1.5° for rotations, 1.9 mm for translations, 2.1% of subjects' body weight for ground reaction forces, 6.6 Nm for torques, 11.2 mm for center of pressure, and 6.3% of maximum fast-dynamic electromyographic activities for EMG. Some significant differences (p<0.05) were found in internal rotation, anterior translation, vertical force and EMG. All differences between quasi-static and fast-dynamic squats were small. 69.5% of compared data were equivalent. In conclusion, this study showed that quasi-static and fast-dynamic squatting activities are comparable in terms of 3D kinematics, 3D kinetics and EMG, although some reservations still remain.
许多研究描述了准静态或动态下蹲活动期间下肢的三维运动学、三维动力学和肌电图（EMG）。一项研究比较了这两种下蹲条件，但仅在健康受试者低速状态下进行，且未提供下肢动力学和肌电图的信息。本研究的目的是对比健康受试者和病理受试者在准静态和快速动态下蹲过程中下肢的三维运动学、三维动力学和肌电图的同步记录。招募了10名受试者：5名健康受试者和5名骨关节炎受试者。一个运动捕捉系统、测力板和表面电极分别记录下肢的三维运动学、三维动力学和肌电图。每个受试者进行一次准静态下蹲以及几次从膝关节屈曲0°到70°的快速动态下蹲。比较了两种下蹲条件下准静态和快速动态膝关节屈伸角度相似的位置。准静态和快速动态下蹲之间的平均差异为：旋转1.5°，平移1.9毫米，地面反作用力为受试者体重的2.1%，扭矩6.6牛米，压力中心11.2毫米，肌电图为最大快速动态肌电活动的6.3%。在内旋、前向平移、垂直力和肌电图方面发现了一些显著差异（p<0.05）。准静态和快速动态下蹲之间的所有差异都很小。69.5%的比较数据是等效的。总之，本研究表明，尽管仍有一些保留意见，但准静态和快速动态下蹲活动在三维运动学、三维动力学和肌电图方面具有可比性。
