OBJECTIVES Gait impairment dramatically affects stroke patients' functional independence. The Ekso™ is a wearable powered exoskeleton able to improve over-ground gait abilities, but the relationship between the cortical gait control mechanisms and lower limbs kinematics is still unclear. Our aims are: to assess whether the Ekso™ induces an attention-demanding process with prefrontal cortex activation during a gait task; to describe the relationship between the gait-induced muscle activation pattern and the prefrontal cortex activity. METHODS We enrolled 22 chronic stroke patients and 15 matched controls. We registered prefrontal cortex (PFC) activity with functional Near-Infrared Spectroscopy (fNIRS) and muscle activation with surface-electromyography (sEMG) during an over-ground gait task, performed with and without the Ekso™. RESULTS We observed prefrontal cortex activation during normal gait and a higher activation during Ekso-assisted walking among stroke patients. Furthermore, we found that muscle hypo-activation and co-activation of non-paretic limb are associated to a high prefrontal metabolism. CONCLUSIONS Among stroke patients, over-ground gait is an attention-demanding task. Prefrontal activity is modulated both by Ekso-assisted tasks and muscle activation patterns of non-paretic lower limb. Further studies are needed to elucidate if other Ekso™ settings induce different cortical and peripheral effects. SIGNIFICANCE This is the first study exploring the relationship between central and peripheral mechanisms during an Ekso-assisted gait task.

中文翻译：

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慢性中风的外骨骼辅助步态：肌肉激活模式和前额叶皮层活动的肌电图和功能性近红外光谱研究

目的 步态障碍显着影响中风患者的功能独立性。Ekso™ 是一种可穿戴动力外骨骼，能够提高地面步态能力，但皮质步态控制机制与下肢运动学之间的关系仍不清楚。我们的目标是：评估 Ekso™ 是否在步态任务期间通过前额叶皮层激活诱导注意力需求过程；描述步态诱导的肌肉激活模式与前额叶皮层活动之间的关系。方法 我们招募了 22 名慢性卒中患者和 15 名匹配的对照。我们使用功能性近红外光谱 (fNIRS) 和表面肌电图 (sEMG) 记录了前额叶皮层 (PFC) 活动，并在使用和不使用 Ekso™ 的地面步态任务期间进行了肌肉激活。结果 我们观察到中风患者在正常步态期间前额叶皮层激活，在 Ekso 辅助行走期间观察到更高的激活。此外，我们发现非瘫痪肢体的肌肉低激活和共激活与高前额叶代谢有关。结论 在中风患者中，离地步态是一项需要注意的任务。前额叶活动受 Ekso 辅助任务和非瘫痪下肢的肌肉激活模式的调节。需要进一步的研究来阐明其他 Ekso™ 设置是否会引起不同的皮质和外周效应。意义 这是第一项探索 Ekso 辅助步态任务中中枢和外周机制之间关系的研究。