ABSTRACT This study investigates the feasibility of fabricating a dynamic foot prosthesis for lower knee amputees using a composite material composed of polypropylene (PP), fresh cow bone powder (FCBP), and silicon rubber (Si). Nine samples with variable compositions of these components were prepared and subjected to mechanical testing to evaluate their compression strength, elongation, factor of safety, impact energy, and energy storage efficiency. The results demonstrated that the innovative composite made up of 68% PP, 18% FCBP, and 14% Si has exhibited the highest foot energy storage efficiency of 67.83%, which is within the standards of 63–100%. Furthermore, the synthesised dynamic foot has obtained excellent mechanical properties and a maximum factor of safety of 2.71. Accordingly, this study proposes that the developed composite material has the potential to be utilised for the fabrication of dynamic foot prostheses, as it offers a set of improved mechanical properties and potentially enhances the mobility and quality of life for lower knee amputees.