A Multi-DOF Rehabilitation System for Recovery of Ankle Circumduction in Orthopedic Patients

Individuals recovering from stroke, paralysis, or orthopedic trauma frequently experience significant limitations in ankle movement. This restricted mobility not only impairs the ankle joint but also disrupts the entire gait cycle, leading to difficulties in walking, balance, and posture maintenance. Prolonged immobility further causes muscle stiffness, reduced blood circulation, and poor neuromuscular coordination, all of which delay recovery. Conventional physiotherapy sessions depend heavily on continuous therapist supervision and manual assistance, making consistent rehabilitation challenging, especially outside clinical environments. To overcome these issues, this project introduces a servo-driven ankle rehabilitation system that is cost-effective, compact, and user-friendly. The proposed device is designed to restore ankle circumduction movement accurately through synchronized servo operation, ensuring repeated and controlled motion cycles. The ESP32 microcontroller governs the system, generating precise PWM signals to regulate the angular displacement and rotational speed of each servo motor. Moreover, its integrated IoT capabilities enable real-time data monitoring, wireless control, and storage via mobile or computer interfaces. The device operates in two distinct modes: Manual Mode utilizes an analog joystick, allowing patients to perform self-assisted exercises for active muscle engagement, while Automatic Mode allows configuration through a mobile application, enabling adjustments of motion cycles, angular limits, and speed parameters. Once initiated, the system executes consistent circumduction movements to facilitate neuromuscular re-education. Preliminary testing with MG996R servos indicates satisfactory performance, providing approximately 11 kg.cm (1.1 N.m) stall torque. The device’s lightweight structure, low energy consumption, and compact form make it suitable for both home-based and clinical rehabilitation applications.