Personalized musculoskeletal model based multi-muscle force analysis for amputees with transtibial prostheses

Understanding the biomechanical effects of transtibial prostheses is essential for their optimization and for improving amputee mobility. This study investigated how different prostheses impact intra-limb muscle coordination and inter-limb muscle force symmetry using personalized musculoskeletal models based on the sDIMS platform. Five transtibial amputees participated in gait trials with passive prostheses and active prostheses under varying damping conditions. The results were compared to those of five able-bodied controls. Through multi-muscle force analysis, we quantified muscle force magnitudes, identified coordination patterns, and evaluated inter-limb symmetry of multiple lower limb muscles using correlation coefficients, cyclograms, and symmetry indices. The results revealed distinct compensatory strategies in the intact limb based on group-level analysis. Furthermore, personalized evaluation based on multi-muscle force analysis enabled effective assessment of different prosthesis configurations in a subject-specific manner. These findings suggest that the proposed framework can improve prosthetic parameter selection and support the development of personalized control strategies, offering practical guidance for transtibial prosthesis optimization.