This paper provides a comprehensive review of the structural features and biomechanical functions of modern passive and semi-active knee prostheses, followed by comparative analysis. Based on findings from scientific literature and engineering practice, a new conceptual knee prosthesis was developed using a modular design approach. The proposed structure was modeled in SolidWorks, and its kinematic behavior and structural integrity were quantitatively evaluated through finite element analysis (FEA). The knee module was specifically designed to integrate with previously developed ankle and foot prosthetic components via an adapter interface. This modular approach allows the prosthesis to be configured according to the individual clinical needs of the patient. Simulation results confirmed that the proposed design meets the requirements for motion accuracy and structural reliability. In future work, the physical prototype will be manufactured using 3D printing with PLA plastic as an initial test material, followed by fabrication with high-strength engineering plastics or metal alloys. This study represents a critical early step toward the development of a fully functional, adaptive lower-limb prosthetic system.

The study presents the conceptual development and simulation of a robotic exoskeleton for ankle rehabilitation. The device is designed for ankle rehabilitation in patients with musculoskeletal disorders, injuries, or neurological diseases. The exoskeleton is equipped with three linear electric actuators that provide precise control of joint movements in multiple planes, allowing dorsiflexion and plantar flexion, inversion, and eversion. By utilizing a screw drive, the exoskeleton provides smooth and controlled movements, significantly reducing the risk of re-injury and improving rehabilitation. Simulation of the device and simulation results showed its high compatibility with the biomechanical features of the ankle joint. Virtual testing confirmed that the exoskeleton provides the smooth, controlled movements necessary for effective rehabilitation. Due to its ability to adapt to the individual physical capabilities of the patient, the device can be used in both active and passive forms of movement support. The results of the study demonstrate the potential of the exoskeleton in clinical applications, including its use in rehabilitation centers and at home. Its cost-effectiveness, ease of use, and high accuracy of movement control make this device a promising solution for restoring the functions of the lower extremities in patients with various musculoskeletal disorders.