From concept to prototype: Designing an assistive device for multicompartmental knee osteoarthritis

Knee osteoarthritis (KOA) is a progressive condition that increasingly affects multiple compartments of the knee, yet most existing orthotic devices are designed for unicompartmental disease and provide only partial relief. Current options such as unloader braces, knee sleeves, and patellofemoral braces are limited by rigid, single degree-of-freedom structures, inconsistent levels of assistance, and restricted flexion-extension, which can negatively impact comfort, gait, and long-term adherence. Clinical studies also report variable outcomes in pain reduction, function, and load redistribution, further highlighting design shortcomings. To address these gaps, this study integrates findings from a comprehensive literature review into the conceptualisation and prototyping of a novel assistive device aimed at multicompartmental KOA. A 3D-printed prototype was developed featuring an adjustable spring mechanism for variable assistive force, together with a sensor interface for preliminary data collection. The design prioritises biomechanical performance and user comfort, demonstrating the feasibility of a new orthotic concept while outlining opportunities for further refinement, clinical validation, and innovation in this field.