Lower-limb prosthetic mechanisms: recent progress, control innovations and barriers to real-world adoption.

Abstract

Lower-limb impairments caused by amputation, stroke or paralysis severely impact mobility and independence. Assistive technologies for these conditions include passive prostheses, powered limbs and robotic exoskeletons, each offering distinct advantages in simplicity, functionality and adaptability. Recent advancements have significantly enhanced these systems through innovations in biomechanics, intelligent control and materials engineering. Improvements in biomechanical modelling and neuromuscular interfaces such as electromyography (EMG) and pressure-based sensors have enhanced user intent recognition and facilitated more adaptive gait control. Intelligent control strategies, including machine learning algorithms, variable impedance control and phase-based coordination, enable responsive adaptation to different terrains and movement demands. In parallel, advancements in materials such as carbon fibre composites and 3D-printed polymers have enabled the creation of lightweight, robust and customisable components that enhance user comfort and device performance. These innovations demonstrate meaningful gains in gait symmetry, stability and metabolic efficiency. However, major challenges remain in developing intuitive and reliable control outside laboratory settings, achieving seamless adaptation to unpredictable terrain, ensuring long-term user comfort and fit and reducing weight and energy consumption to support full-day use. Limited real-world clinical validation and high cost further restrict widespread adoption. Continued progress will depend on integrated, human-centred co-design that combines efficient actuation, robust multimodal sensing, intelligent control and clinically meaningful evaluation. This review synthesises current research trends and highlights priority directions towards prosthetic systems that are more functional, accessible and capable of supporting confident everyday mobility.