Development and Validation of the Novel Exergame-Integrated Robotic Stepper Device for Seated Lower Limb...

Seated rehabilitation is essential in early-stage recovery for patients who can sit but cannot stand or walk. Robotic-based lower limb rehabilitation provides precise, task-specific training for recovery, but its application in seated exercises remains limited, creating a significant gap in early-stage rehabilitation. This study presents a novel exergame-integrated robotic stepper for seated bilateral and multi-joint lower limb rehabilitation. Twenty healthy participants performed seated stepping exercises across eight modes: passive (G0), three-level assistive(G1-G3), active (G4), and three-level resistive (G5-G7). Results demonstrated a strong correlation between the stepper's tilt angle and the ankle, knee, and hip joints. The device maintained consistent ROM for these joints across all modes, ensuring reliable joint engagement regardless of resistance or assistance levels. Weight shift increased progressively from passive (G0) to high resistance (G7), with higher shifts observed as assistance decreased and resistance increased. In assistive modes, a significant increase of 47.16% in weight shift was observed at low assistance (G3) (p <0.0167). In resistive modes, weight shift increased significantly by 86.08% in medium resistance (G6) and by 129.7% at high resistance (G7) (p <0.0167). Muscle activation significantly increased progressively from passive (G0) to high resistance (G7), with greater activations observed as assistance levels decreased and resistance levels increased (p <0.0083). These findings indicate that robotic stepper can be a versatile tool in progressive stroke rehabilitation, effectively adapting to different rehabilitation needs, from early-stage support to muscle strengthening.