Müller Juliane, Müller Steffen, Engel Tilman, Reschke Antje, Baur Heiner, Mayer Frank
University Outpatient Clinic, Sports Medicine & Sports Orthopaedics, University of Potsdam, Germany.
University Outpatient Clinic, Sports Medicine & Sports Orthopaedics, University of Potsdam, Germany.
J Biomech. 2016 Apr 11;49(6):933-938. doi: 10.1016/j.jbiomech.2015.09.041. Epub 2015 Oct 27.
Reflex activity of the lower leg muscles involved when compensating for falls has already been thoroughly investigated. However, the trunk׳s role in this compensation strategy remains unclear. The purpose of this study, therefore, was to analyze the kinematics and muscle activity of the trunk during perturbed walking. Ten subjects (29 ± 3 yr;79 ± 11 cm;74 ± 14 kg) walked (1m/s) on a split-belt treadmill, while 5 randomly timed, right-sided perturbations (treadmill belt deceleration: 40 m/s(2)) were applied. Trunk muscle activity was assessed with a 12-lead-EMG. Trunk kinematics were measured with a 3D-motion analysis system (12 markers framing 3 segments: upper thoracic area (UTA), lower thoracic area (LTA), lumbar area (LA)). The EMG-RMS [%] (0-200 ms after perturbation) was analyzed and then normalized to the RMS of normal walking. The total range of motion (ROM;[°]) for the extension/flexion, lateral flexion and rotation of each segment were calculated. Individual kinematic differences between walking and stumbling [%; ROM] were also computed. Data analysis was conducted descriptively, followed by one- and two-way ANOVAs (α=0.05). Stumbling led to an increase in ROM, compared to unperturbed gait, in all segments and planes. These increases ranged between 107 ± 26% (UTA/rotation) and 262 ± 132% (UTS/lateral flexion), significant only in lateral flexion. EMG activity of the trunk was increased during stumbling (abdominal: 665 ± 283%; back: 501 ± 215%), without significant differences between muscles. Provoked stumbling leads to a measurable effect on the trunk, quantifiable by an increase in ROM and EMG activity, compared to normal walking. Greater abdominal muscle activity and ROM of lateral flexion may indicate a specific compensation pattern occurring during stumbling.
在跌倒补偿过程中涉及的小腿肌肉反射活动已经得到了充分研究。然而，躯干在这种补偿策略中的作用仍不明确。因此，本研究的目的是分析在受干扰行走过程中躯干的运动学和肌肉活动。十名受试者（年龄29±3岁；身高79±11厘米；体重74±14千克）在分体式跑步机上以1米/秒的速度行走，同时施加5次随机定时的右侧干扰（跑步机皮带减速：40米/秒²）。使用12导联肌电图评估躯干肌肉活动。用三维运动分析系统（12个标记点标记3个节段：上胸部区域（UTA）、下胸部区域（LTA）、腰部区域（LA））测量躯干运动学。分析肌电图均方根值（EMG-RMS）[百分比]（干扰后0至200毫秒），然后将其归一化为正常行走的均方根值。计算每个节段伸展/屈曲、侧屈和旋转的总运动范围（ROM；[°]）。还计算了行走和绊倒之间的个体运动学差异[百分比；ROM]。进行描述性数据分析，随后进行单因素和双因素方差分析（α=0.05）。与未受干扰的步态相比，绊倒导致所有节段和平面的运动范围增加。这些增加幅度在107±26%（UTA/旋转）至262±132%（UTS/侧屈）之间，仅在侧屈方面具有显著性。绊倒期间躯干的肌电图活动增加（腹部：665±283%；背部：501±215%），各肌肉之间无显著差异。与正常行走相比，诱发的绊倒对躯干产生了可测量的影响，可通过运动范围和肌电图活动的增加来量化。更大的腹部肌肉活动和侧屈运动范围可能表明绊倒期间出现了特定的补偿模式。
