Biomechanical Analysis of Prosthetic Knee Joint Performance for Transfemoral Amputees in Nigeria: Gait and Load Analysis

The biomechanical performance of prosthetic knee joints available to transfemoral amputees in Nigeria determines functional walking ability and physical health outcomes, but systematic biomechanical characterisation of prosthetic knee performance under Nigerian walking conditions and amputee population characteristics has not been conducted. This study presents a biomechanical analysis of prosthetic knee joint performance for transfemoral amputees in Nigeria, combining gait laboratory measurements and load cell analysis at the National Orthopaedic Hospital Enugu. Fifteen transfemoral amputees using three categories of prosthetic knee joint, specifically single-axis, polycentric, and microprocessor-controlled knees, participated in standardized gait analysis. Three-dimensional gait analysis was performed using a VICON motion capture system measuring kinematic and kinetic parameters during level walking at self-selected and standardized speeds. Residual limb-prosthetic socket interface pressures were measured using a pressure mapping system. Oxygen consumption during walking as a measure of metabolic walking efficiency was assessed by portable spirometry. Gait symmetry indices, prosthetic knee flexion angle ranges, and prosthetic side stance-to-swing ratio were computed as primary biomechanical outcome measures. Results show that microprocessor-controlled knee users demonstrated significantly more symmetrical gait, greater prosthetic knee flexion range during swing phase, and lower metabolic cost of walking compared to single-axis and polycentric knee users. However, prosthetic socket fit was identified as a confounding variable, with poor socket fit significantly impairing gait symmetry independent of knee joint type. The study provides evidence supporting microprocessor knee provision in functionally appropriate Nigerian amputee patients. Keywords: prosthetic knee joint, transfemoral amputee, biomechanical analysis, gait analysis, Nigeria.