Compact Waist Rehabilitation Robot Inspired by McKenzie Therapy: Design, Analysis and Validation

Aiming at solving the problems of low compliance and unsatisfactory therapeutic effect in most existing waist rehabilitation robots, this letter presents a compact waist rehabilitation robot (CWRR) for patients with low back pain (LBP). First, the CWRR with a rigid pose adjustment mechanism and a soft curvature adjustment mechanism is designed to adapt to the waist movement and adjust lumbar curvature. Then, the kinematic analysis was conducted using the closed-loop vector method and the phenomenological theory model. Finally, unit mechanism tests and a comprehensive prototype test were carried out to validate the rationality of the theoretical models and the adaptability and compliance of the CWRR. The CWRR adjusted the curvature angle within the range of 10–60 degrees with small errors. Under different pose and curvature conditions, the man-machine contact pressure was lower or slightly higher than the low-pressure regime threshold (10 kPa). Experimental results show that the CWRR possesses potential clinical applications for patients with LBP disease and can provide theoretical and technical reserves for the research and development of curvature-adjustment waist rehabilitation robots.