Abstract
The purpose of this study was to design and develop a robotic device for ankle rehabilitation that is capable of reproducing physiological foot movements in three anatomical planes and supporting both active and passive therapy modes. The device is intended for use in rehabilitation therapy after injuries and surgeries of the ankle joint, for patients with neurological impairments of the lower limb motor function, and for biomechanical studies of foot motion.A computer aided design approach was applied to construct a platform capable of dorsiflexion and plantarflexion, inversion and eversion, and internal and external rotation. The mechanical system included a perforated fixation platform adapted to the anatomy of the foot, arc guides with roller supports, three linear actuators for movement conversion, and a central bearing unit to provide vertical axis rotation. Structural elements were manufactured from anodized aluminum and tool steel to ensure strength, low weight, and resistance to corrosion. The control system was based on a microcontrollerarchitecture with position encoders, drivers, and safety mechanisms. The software supported manual, semi-automatic, and automatic therapy modes, with the ability to calibrate and store patient parameters.Kinematic modeling confirmed the possibility of achieving the required range of motion: dorsiflexion and plantarflexion up to ±25 degrees, inversion and eversion up to ±15 degrees, and smooth internal and external rotations. Simulation demonstrated accurate trajectory control with high repeatability. Biomechanical analysis indicated that the required force range could be achieved with selected actuators, while structural verification in the design software showed maximum stresses and deformations within safe limits.The developed robotic prototype demonstrates feasibility for clinical rehabilitation of the ankle joint, enabling precise reproduction of natural foot movements, secure patient fixation, and adaptable therapy modes. This system provides a promising technological solution to improve recovery outcomes after trauma or surgery and to expand research opportunities in biomechanics.Keywords:ankle joint, rehabilitation, robotics, exoskeleton device, orthopedic procedures