Legs and Walking Lab, Shirley Ryan AbilityLab, Chicago, Illinois, United States.
Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, Illinois, United States.
J Neurophysiol. 2024 Nov 1;132(5):1348-1358. doi: 10.1152/jn.00485.2023. Epub 2024 Sep 18.
Reduced propulsion of the paretic leg contributes to impaired walking in people poststroke. The goal of this study was to determine whether phasic electrical stimulation to the paretic gastrocnemius muscle combined with resistance applied to the nonparetic leg during swing phase while walking would enhance muscle activation of the paretic gastrocnemius and propulsive force of the paretic leg. Fifteen individuals who had a stroke visited the lab once to complete two experimental sessions (i.e., crossover design; session order randomized). Each session consisted of ) treadmill walking with either "motor stimulation and swing resistance" or "swing resistance only" (10-min walking: 1-min baseline, 7-min adaptation to intervention, and 2-min postadaptation) and ) instrumented treadmill walking before and after treadmill walking. Participants showed enhanced muscle activation of the paretic gastrocnemius ( = 0.03) and improved anteroposterior ground reaction force of the paretic leg ( = 0.01) immediately after the treadmill walking with "motor stimulation and swing resistance," whereas no improvements after the walking with "swing resistance only." Those enhanced gastrocnemius muscle activation ( = 0.02) and improved ground reaction force ( = 0.03) were retained until the late postadaptation period and 10 min after treadmill walking, respectively. Walking with "motor stimulation and swing resistance" may enhance forced use of the paretic leg and improve propulsive force of the paretic leg. Applying phasic electrical stimulation to the paretic gastrocnemius muscle and swing resistance to the nonparetic leg during walking can be used as a novel intervention strategy to improve motor control of the paretic leg and walking in people poststroke. Applying targeted motor stimulation to the paretic calf muscle and swing resistance to the nonparetic leg during walking induced significant enhancement in muscle activation of the paretic gastrocnemius and anterior-posterior ground reaction force of the paretic leg, whereas no enhancements were observed after walking with swing resistance only. Furthermore, the enhanced gastrocnemius muscle activation and ground reaction force of the paretic leg were partially retained at the late postadaptation period and 10 min after treadmill walking.
患侧下肢推进力降低是导致脑卒中后患者步行障碍的原因之一。本研究旨在探讨在摆动相时对患侧腓肠肌施以相位性电刺激并对非患侧下肢施加阻力是否会增强患侧腓肠肌的肌肉激活和患侧下肢的推进力。15 名脑卒中患者到实验室进行了两次实验（即交叉设计；随机安排实验顺序）。每次实验都包括：（1）在跑步机上行走，施加“运动刺激和摆动阻力”或“仅摆动阻力”（10 分钟行走：1 分钟基线，7 分钟适应干预，2 分钟适应后）；（2）在跑步机上行走前后进行仪器化跑步机行走。结果显示，在施加“运动刺激和摆动阻力”的跑步机行走后，患者的患侧腓肠肌肌肉激活明显增强（ = 0.03），患侧下肢前后向地面反力也得到改善（ = 0.01），而在施加“仅摆动阻力”的跑步机行走后则没有改善。这种增强的腓肠肌肌肉激活（ = 0.02）和改善的地面反力（ = 0.03）分别在跑步机行走结束后和 10 分钟时仍能保持。施加“运动刺激和摆动阻力”可能会增强对患侧下肢的强制使用，并改善患侧下肢的推进力。在行走时对患侧腓肠肌施以相位性电刺激并对非患侧下肢施加摆动阻力，可能成为改善脑卒中后患者下肢运动控制和行走能力的一种新的干预策略。在行走时对患侧小腿肌肉施加靶向运动刺激并对非患侧下肢施加摆动阻力，可显著增强患侧腓肠肌的肌肉激活和患侧下肢的前后向地面反力，而仅施加摆动阻力则没有增强作用。此外，在跑步机行走结束后和 10 分钟时，患侧腓肠肌的肌肉激活和地面反力仍能部分保持增强。
