Bourgeois Héloïse, Guay-Hottin Rose, Meftah El-Mehdi, Martinez Marina, Bonizzato Marco, Barthélemy Dorothy
Institute of Biomedical Engineering, Polytechnique Montréal, Montréal, QC, Canada.
Electrical Engineering, Polytechnique Montréal, Montréal, QC, Canada.
Sci Rep. 2025 Jul 1;15(1):21362. doi: 10.1038/s41598-025-05741-3.
The primary motor cortex is involved in initiation and adaptive control of locomotion. However, the role of the motor cortex in controlling gait trajectories remains unclear. In animals, cortical neuromodulation allows for precise control of step height. We hypothesized that a similar control framework applies to humans, whereby cortical stimulation would primarily increase foot elevation. Transcranial magnetic stimulation (TMS) was applied over the motor cortex to assess the involvement of the corticospinal tract over the limb trajectory during human walking. Ten healthy adults (aged 20-32 years) participated in treadmill walking at 1.5 km/h. TMS was applied over the left motor cortex at an intensity of 120% of the threshold to elicit a dorsiflexion of the right ankle during the swing phase of gait. Electromyographic (EMG) measurements and three-dimensional (3D) lower limb kinematics were collected. When delivered during the early swing phase, TMS led to a significant increase in the maximum height of the right toe by a mean of 34.9% ± 9.6% (21.4 mm ± 7.9 mm, p = 0.032) and knee height by 52.8% ± 14.1% (28.8 mm ± 7.7 mm, p = 0.0021) across participants. These findings indicate that TMS can influence limb trajectory during walking, highlighting its potential as a tool for studying cortical control of locomotion.
初级运动皮层参与运动的发起和适应性控制。然而，运动皮层在控制步态轨迹中的作用仍不清楚。在动物中，皮层神经调节可实现对步高的精确控制。我们假设类似的控制框架也适用于人类，即皮层刺激主要会增加足部抬高。通过经颅磁刺激（TMS）作用于运动皮层，以评估人类行走过程中皮质脊髓束对肢体轨迹的影响。10名健康成年人（年龄在20 - 32岁之间）以1.5千米/小时的速度在跑步机上行走。TMS以阈值的120%的强度作用于左侧运动皮层，以在步态摆动期引发右踝关节背屈。收集肌电图（EMG）测量数据和三维（3D）下肢运动学数据。当在摆动早期施加TMS时，参与者的右脚趾最大高度平均显著增加34.9%±9.6%（21.4毫米±7.9毫米，p = 0.032），膝部高度增加52.8%±14.1%（28.8毫米±7.7毫米，p = 0.0021）。这些发现表明TMS可在行走过程中影响肢体轨迹，凸显了其作为研究运动皮层控制运动的工具的潜力。
