From the Department of Biological Sciences, Université du Québec à Montréal (UQÀM) (AP, AP-L); CHU Sainte-Justine (CRME) (AP, AP-L, YC, PM, LB); École de kinésiologie et des sciences de l'activité physique, Faculté de Médecine, Université de Montréal (FDM, YC); Centre interdisciplinaire de recherche sur le cerveau et l'apprentissage (CIRCA) (FDM); and Department of Physical Activity Sciences, Université du Québec à Montréal (UQÀM), Montreal, Quebec, Canada (LB).
Am J Phys Med Rehabil. 2021 Nov 1;100(11):1093-1099. doi: 10.1097/PHM.0000000000001713.
The aim of this study was to evaluate kinematic changes and muscle fatigue in jump gait during a walking exercise and the relationship between kinematic changes and muscle fatigue and strength.
This preliminary study included 10 children with cerebral palsy who walk with jump gait. Hip and knee maximal isometric muscle strength were measured using a dynamometer. Then, lower-limb kinematics and electromyography were collected while children walked continuously for 6 min at their self-selected speed. Electromyography median frequency and lower-limb joint angles were compared between the first and the sixth minutes of the walking exercise using t test and Wilcoxon rank test. The relationship between kinematic changes and muscle strength and changes in electromyography median frequency were assessed using correlation analyses.
During stance, maximal knee flexion significantly increased at the sixth minute (P = 0.01) and was associated with knee extensor muscle weakness (ρ = -0.504, P = 0.03). Muscle fatigue was observed only in the gluteus medius muscle (P = 0.01).
Children with cerebral palsy who walked with jump gait and who had knee extensor weakness were more prone to an increase in knee flexion during a continuous walk. The fatigue in the gluteus medius muscle suggests that physical intervention should target the endurance of this muscle to improve jump gait.
本研究旨在评估行走运动中跳跃步态的运动学变化和肌肉疲劳，以及运动学变化与肌肉疲劳和力量之间的关系。
本初步研究纳入 10 名采用跳跃步态行走的脑瘫儿童。使用测力计测量髋关节和膝关节最大等长肌肉力量。然后，在儿童以自身选择的速度连续行走 6 分钟时，收集下肢运动学和肌电图。使用 t 检验和 Wilcoxon 秩检验比较行走运动的前 6 分钟和后 6 分钟的肌电图中位频率和下肢关节角度。使用相关分析评估运动学变化与肌肉力量以及肌电图中位频率变化之间的关系。
在站立阶段，第六分钟时最大膝关节屈曲显著增加（P = 0.01），与膝关节伸肌无力相关（ρ = -0.504，P = 0.03）。仅观察到臀中肌肌肉疲劳（P = 0.01）。
采用跳跃步态行走且膝关节伸肌无力的脑瘫儿童在连续行走时更易出现膝关节屈曲增加。臀中肌疲劳表明，物理干预应针对该肌肉的耐力，以改善跳跃步态。
