Mechanical characterization of prosthetic feet using a Prosthetic Foot Loading Apparatus

A Prosthetic Foot Loading Apparatus (PFLA) was modified and improved to measure the mechanical properties of different prosthetic feet. In this paper the properties of a SACH foot and a Flexwalk foot are examined to demonstrate application of the device. Roll-over shape of the feet was determined using a shank-based coordinate system. Damping ratios (/spl zeta/=0.064 for SACH and /spl zeta/=0.028 for Flexwalk) and resonant frequencies (/spl omega//sub n/=5.46 Hz for SACH and /spl omega//sub n/=2.90 Hz for Flexwalk) were also obtained. Roll-over shapes and damping ratios influence foot performance during walking. The PFLA is valuable for determining mechanical properties of commercially available prosthetic feet and as well as for evaluating design prototypes for new prosthetic feet.