Introduction to Healthy and Post-Stroke Gait and Robotic Gait Assistance

Gait enables humans to interact freely with their environment. It is an extremely complex process that involves the biomechanics of the locomotor system and its neural control. Stroke survivors usually present neural impairments that hamper this gait control. To overcome them, they usually develop compensation mechanisms to achieve a stable and functional walking pattern. Rehabilitation therapies aim at providing, compensating, or re-training impaired motion capabilities. Despite their benefits, community-dwelling hemiparetic walkers still require external tools that assist their gait. In this context, robotic exoskeletons have been postulated as suitable technical solutions to assist impaired walking subjects. Partial exoskeletons have acquired special relevance due to their reduced weight and focused action over the impaired joint function. This chapter briefly introduces the biomechanics and neural control of healthy human gait. Additionally, post-stroke neurological impairments and their effects on the gait are analyzed, specially hemiparetic gait and the compensations mechanisms to deal with it. Afterward, the role of wearable robotic devices in gait rehabilitation and assistance is presented, going further into the state-of-the-art of control strategies for partial robotic exoskeletons, their integration into the impaired gait control, and its possible embodiment.