Engineering a Better Walk

Gait disorders generally lead to limited mobility affecting individuals’ quality life with neuromuscular impairments. Locomotion recovery becomes significant to counteract sedentary living conditions, improving health conditions, and restoring mobility. Human walking is a big challenge that is attracting the focus of researchers around the world. Walking is an integral and indispensable part of every human being’s daily activity. Though cyclic in nature and seeming simple, its complexity cannot be underestimated. The human walk is a coordinated activity of muscles, joints, bones, and sensory mechanisms, and it varies depending on the gender, age, and pathology. Gait rehabilitation using assistive robotics is emerging as an intensive technology for uniform and quantified recovery over conventional therapies. Broadly classifying the robotic rehabilitation systems, they can be of the harness type or wearable exoskeletons. Wearable exoskeletons have gained much attention during the past decade due to ease of customization as per the needs of the affected population. Moreover, exoskeleton-based systems are suitable for both clinical as well as home-based rehabilitation. This chapter describes the application and importance of human biomechanics, gait analysis, particularly in designing, actuation, sensing, and control and performance mapping for indigenous exoskeletons. With the technological advancements in gait analysis, designs are becoming more human-centric. Research is now focused toward the development of ergonomic and anthropometric designs that enable user compliance and comfort. Various aspects including determination of degree of freedom, number of active joints, actuation mechanism, and control strategy are driven by research. Moreover, to be able to mimic human kinematics, precise and accurate sensing mechanisms are required. Due to consideration of application of goniometers, force-sensitive resistors (FSRs) and inertial measurement units are provided. As such devices need sensing and control in real time, reliable hardware is required. This chapter also covers issues related to material selection and controlling approaches required for the reliable system operation. Methods for trajectory and position-based controls are explained along with intent-based control. Controlling requires a means of interaction between the user and exoskeleton. Providing an easy and efficient user interface is, thus, crucial in such devices; this leads to the development of GUI-based human–exoskeleton interface for operation management. It is desirable to implement both mechanical and electrical safety checks to avoid possible injuries to the wearer. The procedures for engineering and clinical trials following necessary medical safety standards are covered in the concluding part of the chapter. Device pre-assessment and safety are possible due to inclusion of gait analysis and biomechanics during the developmental stages, enabling a better rehabilitative system. Thus, transforming an engineering prototype into a safe and efficient rehabilitation device ensures a better walk.