Legs and Walking Lab, Shirley Ryan AbilityLab, 355 E. Erie Street, 23Rd Floor, Chicago, IL, 60611, USA.
Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, IL, USA.
Exp Brain Res. 2024 Jan;242(1):275-293. doi: 10.1007/s00221-023-06744-0. Epub 2023 Nov 28.
The purpose of this study was to examine kinematic and neuromuscular responses of the head and body to pelvis perturbations with different intensities and frequencies during sitting astride in children with CP. Sixteen children with spastic CP (mean age 7.4 ± 2.4 years old) were recruited in this study. A custom designed cable-driven robotic horse was used to apply controlled force perturbations to the pelvis during sitting astride. Each participant was tested in four force intensity conditions (i.e., 10%, 15%, 20%, and 25% of body weight (BW), frequency = 1 Hz), and six force frequency conditions (i.e., 0.5 Hz, 1 Hz, 1.5 Hz, 2 Hz, 2.5 Hz, and 3 Hz, intensity = 20% of BW). Each testing session lasted for one minute with a one-minute rest break inserted between two sessions. Kinematic data of the head, trunk, and legs were recorded using wearable sensors, and EMG signals of neck, trunk, and leg muscles were recorded. Children with CP showed direction-specific trunk and neck muscle activity in response to the pelvis perturbations during sitting astride. Greater EMG activities of trunk and neck muscles were observed for the greater intensities of force perturbations (P < .05). Participants also showed enhanced activation of antagonistic muscles rather than direction-specific trunk and neck muscle activities for the conditions of higher frequency perturbations (P < .05). Children with CP may modulate trunk and neck muscle activities in response to greater changes in intensity of pelvis perturbation during sitting astride. Perturbations with too high frequency may be less effective in inducing direction-specific trunk and neck muscle activities.
本研究旨在探讨脑瘫儿童坐姿时，骨盆受到不同强度和频率的外力干扰时，头部和身体的运动学和神经肌肉反应。本研究共招募了 16 名痉挛型脑瘫儿童（平均年龄 7.4±2.4 岁）。使用定制的电缆驱动机器人马在坐姿时向骨盆施加受控的力干扰。每个参与者在四个力强度条件下（即，10%、15%、20%和 25%的体重（BW），频率=1Hz）和六个力频率条件下（即，0.5Hz、1Hz、1.5Hz、2Hz、2.5Hz 和 3Hz，强度=20%的 BW）进行测试。每个测试阶段持续一分钟，两个阶段之间插入一分钟的休息时间。使用可穿戴传感器记录头部、躯干和腿部的运动学数据，并记录颈部、躯干和腿部肌肉的肌电图信号。脑瘫儿童在坐姿时对骨盆外力干扰表现出特定方向的躯干和颈部肌肉活动。较大的力干扰强度观察到较大的躯干和颈部肌肉肌电图活动（P<.05）。对于更高频率的干扰条件，参与者还表现出拮抗肌的增强激活，而不是特定方向的躯干和颈部肌肉活动（P<.05）。脑瘫儿童可能会调节躯干和颈部肌肉活动，以应对坐姿时骨盆干扰强度的较大变化。频率过高的干扰可能不太有效诱导特定方向的躯干和颈部肌肉活动。
