Advances in the development of active lower limb prostheses for improving people with amputation locomotion: A review

• Active prostheses for lower limbs boost mobility for amputees. • Hydraulic actuators deliver enough power for challenging locomotion. • Real-time control systems enable prostheses to adapt to dynamic environments. • Integration of lightweight materials enhances ergonomic aspects and mobility This review paper analyzes the progress in developing active lower limb prostheses to improve locomotion in individuals with amputations, focusing on actuation principles and control models. A total of 29 prostheses were analyzed, including 21 for transfemoral amputations and 8 for transtibial amputations. Active prostheses utilizing electromechanical, hydraulic, and pneumatic actuation systems have significantly enhanced locomotion capabilities for amputated individuals. Electromechanical systems dominate due to their precision and flexibility, while hydraulic systems provide greater power to tackle challenging terrains. Control models, including finite state machines, echo principles, and advanced algorithms based on machine learning, enable prostheses to adapt to the individual needs of users during various phases of walking. However, challenges still exist in improving motion control, user stability, energy efficiency, autonomy, and adaptability of prostheses, necessitating further research and technological improvements.