This paper focuses on the development of an adjustable lower limb exoskeleton (ALLE) to help people with lower limb limitations, especially the elderly, to gain mobility, independence, comfort, and assistance. In order to improve the lives of people with lower limb impairments the devised ALLE is composed of actuator gear mechanisms (AGMs), adjustable leg links, joints, and control and electric circuits. The ALLE can be operated in both manual (as a rehabilitation device) and EMG mode (for elderly user’s assistance). For precise movements, a PID control, microcontroller, motor drivers, optical encoders, EMG electrodes, and EMG sensor module are incorporated. The performance of developed ALLE is tested for both manual and EMG modes during knee motion, hip motion, sit-stand motion, and walking motion. The testing shows that the performance of the devised ALLE is quite adequate and promising as an assistive device for users with constrained lower limb mobility.

Index Terms- EMG-controlled, Adjustable lower limb, Exoskeleton, Rehabilitation robotics, Assistive technology, Biomedical engineering.