Design and Evaluation of a Trunk–Limb Robotic Exoskeleton for Gait Rehabilitation in Cerebral Palsy

Most pediatric exoskeletons for cerebral palsy (CP) focus on lower-limb assistance and neglect trunk control, limiting rehabilitation outcomes. This study presents a self-aligning trunk-limb exoskeleton that integrates trunk stabilization with active lower-limb support. The design includes a hip-waist rapid adjustment mechanism, a bioinspired gear-rolling knee joint, modular thigh-shank structures, a trunk support module, and a body-weight support device. To enable transparent and coordinated assistance under pathological gait conditions, a continuous gait progress-based multi-joint control framework is developed. Joint motion is described as continuous gait progress over the full gait cycle (0-100%), and joint-specific progress estimates are fused into a unified system-level reference using observability-weighted circular statistics. Inter-joint coordination is achieved through phase-consistency-based temporal modulation implemented, enabling smooth synchronization while preserving joint-level autonomy and motion continuity. Technical evaluation-comprising kinematic misalignment analysis, simulation validation, and gait trials-demonstrated a 66.8% reduction in hip misalignment and an 87.4% reduction in knee misalignment. Gait parameters under exoskeleton-assisted walking closely matched baseline walking, confirming natural kinematic preservation without interference. These results indicate that the proposed trunk-limb exoskeleton improves human-robot synergy, enhances postural stability, and provides a promising solution for pediatric gait rehabilitation in CP.