Department of Biological Sciences, Université du Québec à Montréal (UQÀM), C.P. 8888, succursale Centre-Ville, Montreal (Quebec), H3C 3P8, Canada; CHU Sainte-Justine (CRME) 5200 rue Bélanger Est, Montreal (Quebec), H1T 1C9, Canada.
École de kinésiologie et des sciences de l'activité physique, Faculté de Médecine, Université de Montréal, 2100, boul. Édouard-Montpetit, Bureau 8202, Montreal (Quebec), H3T 1J4, Canada.
Gait Posture. 2019 Jul;72:22-27. doi: 10.1016/j.gaitpost.2019.05.021. Epub 2019 May 20.
A deterioration of crouch gait was found in a group of children with cerebral palsy (CP) after a short walking exercise. The increased knee flexion reported after a continuous walk could be related with muscle fatigue and muscle strength.
Does muscle fatigue appears at the end of a walking exercise in children with CP who walk in a crouch gait?
Eleven children with cerebral palsy (GMFCS I to III) who walk in a crouch gait were included. Isometric muscle strength was assessed using a handheld dynamometer. Children were asked to walk for 6 min at comfortable speed. Spatio-temporal, kinematic and electromyographic (EMG) measurements were recorded at the first and the last minute of the 6-minute walking exercise. Muscle fatigue was evaluated using the shift of EMG signals median frequency.
There was no significant difference in walking speed, cadence, and step length at the end of the 6mwe. Maximal and mean anterior pelvic tilt decreased and knee flexion increased (p < 0.05). Rectus femoris EMG median frequency decreased (p < 0.05). The median frequency in other muscles did not decrease significantly. Greater hip extensor strength was associated with lesser knee flexion at the end of the 6-minute walking exercise (p < 0.05).
The increase in knee flexion at the end of the 6-minute walking exercise can be explained by muscle fatigue found in rectus femoris. Hip extensor strength can limit the deterioration of crouch gait after a 6-minute walking exercise representative of daily activities.
在一组脑瘫（CP）儿童进行短暂步行运动后，发现其蹲伏步态恶化。连续行走后报告的膝关节屈曲增加可能与肌肉疲劳和肌肉力量有关。
在蹲伏步态行走的 CP 儿童结束步行运动时是否会出现肌肉疲劳？
纳入 11 名蹲伏步态行走的脑瘫（GMFCS I 至 III 级）儿童。使用手持测力计评估等长肌肉力量。要求儿童以舒适的速度行走 6 分钟。在 6 分钟步行运动的第一分钟和最后一分钟记录时空、运动学和肌电图（EMG）测量值。使用 EMG 信号中值频率的偏移来评估肌肉疲劳。
6mwe 结束时，行走速度、步频和步长无显著差异。最大和平均前骨盆倾斜减小，膝关节屈曲增加（p<0.05）。股直肌 EMG 中值频率降低（p<0.05）。其他肌肉的中值频率没有显著降低。髋关节伸肌力量较大与 6 分钟步行运动结束时膝关节屈曲较小相关（p<0.05）。
6 分钟步行运动结束时膝关节屈曲增加可解释为股直肌的肌肉疲劳。髋关节伸肌力量可以限制代表日常活动的 6 分钟步行运动后蹲伏步态的恶化。
