In this study, a test apparatus was designed and fabricated to quantitatively evaluate the flexion–extension performance of pneumatic and electronic four-bar linkage knee prostheses. Current domestic evaluation systems for knee prostheses remain lim...
In this study, a test apparatus was designed and fabricated to quantitatively evaluate the flexion–extension performance of pneumatic and electronic four-bar linkage knee prostheses. Current domestic evaluation systems for knee prostheses remain limited to mechanical and static performance tests and lack a standardized dynamic testing platform that reflects the moving center-of-rotation characteristics of four-axis knee mechanisms. To address this limitation, the present study aimed to develop a test platform capable of precisely replicating the actual motion trajectory of knee prostheses and enabling quantitative assessment of flexion– extension performance.
To this end, the kinematic structure of the target prosthetic knees was first analyzed, and nonlinear simultaneous equations based on inverse kinematics were formulated. Numerical analysis combined with global and local search–based optimization was then applied to determine the optimal coordinates of the fixed joints (E and G). Structural and dynamic analyses were subsequently performed to verify the mechanical stability and kinematic consistency of the designed mechanism, and a prototype was fabricated. ROM(Range of Motion) validation using a laser tracker demonstrated that the apparatus accurately reproduced the target ROM of 170°, achieving 170.01°. Dynamic ROM tests conducted using the fabricated system further confirmed that the proposed apparatus enables reliable quantitative evaluation of flexion–extension motion.
The apparatus proposed in this study represents the first kinematic-based dynamic evaluation platform for four-axis knee prostheses in Korea. It is expected to contribute to the advancement of domestic prosthetic evaluation systems, including analyses of knee damping characteristics, dynamic durability assessment, and the establishment of standardized performance test methods.