Hu Nijia, Piirainen Jarmo M, Kidgell Dawson J, Walker Simon, Avela Janne
NeuroMuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, FI-40014 Jyväskylä, Finland.
Sports Technology Program, Faculty of Sport and Health Sciences, University of Jyväskylä, FI-88610 Vuokatti, Finland.
Brain Sci. 2023 Aug 15;13(8):1209. doi: 10.3390/brainsci13081209.
Sensorimotor training and strength training can improve balance control. Currently, little is known about how repeated balance perturbation training affects balance performance and its neural mechanisms. This study investigated corticospinal adaptation assessed by transcranial magnetic stimulation (TMS) and Hoffman-reflex (H-reflex) measurements during balance perturbation induced by perturbation training. Fourteen subjects completed three perturbation sessions (PS1, PS2, and PS3). The perturbation system operated at 0.25 m/s, accelerating at 2.5 m/s over a 0.3 m displacement in anterior and posterior directions. Subjects were trained by over 200 perturbations in PS2. In PS1 and PS3, TMS and electrical stimulation elicited motor evoked potentials (MEP) and H-reflexes in the right leg soleus muscle, at standing rest and two time points (40 ms and 140 ms) after perturbation. Body sway was assessed using the displacement and velocity of the center of pressure (COP), which showed a decrease in PS3. No significant changes were observed in MEP or H-reflex between sessions. Nevertheless, Δ MEP at 40 ms demonstrated a positive correlation with Δ COP, while Δ H-reflex at 40 ms demonstrated a negative correlation with Δ COP. Balance perturbation training led to less body sway and a potential increase in spinal-level involvement, indicating that movement automaticity may be suggested after perturbation training.
感觉运动训练和力量训练可以改善平衡控制。目前，关于重复平衡扰动训练如何影响平衡表现及其神经机制知之甚少。本研究调查了在扰动训练引起的平衡扰动期间，通过经颅磁刺激（TMS）和霍夫曼反射（H反射）测量评估的皮质脊髓适应性。14名受试者完成了三个扰动训练阶段（PS1、PS2和PS3）。扰动系统以0.25米/秒的速度运行，在前后方向0.3米的位移上以2.5米/秒的速度加速。受试者在PS2中接受了200多次扰动训练。在PS1和PS3中，TMS和电刺激在站立休息时以及扰动后的两个时间点（40毫秒和140毫秒）诱发右腿比目鱼肌的运动诱发电位（MEP）和H反射。使用压力中心（COP）的位移和速度评估身体摆动，结果显示PS3中的身体摆动有所减少。各训练阶段之间MEP或H反射未观察到显著变化。然而，40毫秒时的ΔMEP与ΔCOP呈正相关，而40毫秒时的ΔH反射与ΔCOP呈负相关。平衡扰动训练导致身体摆动减少，脊髓水平的参与可能增加，这表明扰动训练后可能会出现运动自动性。
