Recent developments and challenges of lower extremity exoskeletons

Lower extremity exoskeletons (LEEs) are wearable robotic systems designed to help people with mobility impairments or to enhance the physical abilities of able-bodied individuals. These devices integrate human intelligence and robot power to assist with movement, strength, and endurance. LEEs are used in gait rehabilitation to provide repetitive and intensive training for patients with mobility disorders, helping them to regain musculoskeletal strength and motor control. They can also be used for human locomotion assistance, enabling paralyzed patients to stand, sit, and walk. Additionally, LEEs can augment the physical abilities of able-bodied individuals for tasks such as carrying heavy loads. Motion data acquisition is crucial for controlling exoskeletons effectively. Sensors measure kinematic, kinetic, and bioelectric data to recognize the wearer's motion intention, analyze gait patterns, and evaluate performance. Control strategies, such as trajectory tracking and assist-as-needed, are used to provide appropriate assistance based on the wearer's needs and abilities.

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  LEEs have shown great improvements in performance, wearability, and portability in recent years, with advancements in actuators, human-exoskeleton interfaces, and power supplies.
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  Current LEEs face limitations such as being heavy, having limited torque and power, affecting normal human gait biomechanics, and being expensive.
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  Future research should focus on developing lightweight and energy-efficient exoskeletons with improved actuators, human-exoskeleton interfaces, safety features, and lower costs to make them more accessible and practical for a wider range of users.