Laboratory for Biomechanics and Biomaterials, Department of Orthopedics, Hannover Medical School, Hannover, Germany.
CNRS LIRIS, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France.
Sci Rep. 2021 Nov 1;11(1):21351. doi: 10.1038/s41598-021-00658-z.
Post-stroke patients present various gait abnormalities such as drop foot, stiff-knee gait (SKG), and knee hyperextension. Functional electrical stimulation (FES) improves drop foot gait although the mechanistic basis for this effect is not well understood. To answer this question, we evaluated the gait of a post-stroke patient walking with and without FES by inverse dynamics analysis and compared the results to an optimal control framework. The effect of FES and cause-effect relationship of changes in knee and ankle muscle strength were investigated; personalized muscle-tendon parameters allowed the prediction of pathologic gait. We also predicted healthy gait patterns at different speeds to simulate the subject walking without impairment. The passive moment of the knee played an important role in the estimation of muscle force with knee hyperextension, which was decreased during FES and knee extensor strengthening. Weakening the knee extensors and strengthening the flexors improved SKG. During FES, weak ankle plantarflexors and strong ankle dorsiflexors resulted in increased ankle dorsiflexion, which reduced drop foot. FES also improved gait speed and reduced circumduction. These findings provide insight into compensatory strategies adopted by post-stroke patients that can guide the design of individualized rehabilitation and treatment programs.
脑卒中患者表现出各种步态异常，如足下垂、僵直膝步态（SKG）和膝关节过伸。功能性电刺激（FES）可改善足下垂步态，但这种效果的机制基础尚不清楚。为了回答这个问题，我们通过逆动力学分析评估了一位脑卒中患者在使用和不使用 FES 时的步态，并将结果与最优控制框架进行了比较。我们研究了 FES 的效果以及膝关节和踝关节肌肉力量变化的因果关系；个性化的肌肉肌腱参数允许预测病理性步态。我们还预测了不同速度下的健康步态模式，以模拟无损伤的受试者行走。在膝关节过伸时，膝关节的被动力矩在肌肉力量估计中起着重要作用，而 FES 和膝关节伸肌强化可降低膝关节的过伸。弱化膝关节伸肌和强化屈肌可改善 SKG。在 FES 期间，弱的踝关节跖屈肌和强的踝关节背屈肌导致踝关节背屈增加，从而减少足下垂。FES 还可以提高步态速度并减少回旋。这些发现为脑卒中患者采用的代偿策略提供了深入了解，这可以指导个体化康复和治疗方案的设计。
