Fig. 3: Parallelism between the human foot and artificial feet.

a On the left, the bones constituting the longitudinal arches, the plantar fascia, and the intrinsic muscles in the sole are emphasized in the human foot. On the right, the anthropomorphic adaptive prosthesis SoftFoot Pro. b–d Case study I and e, f case study II: participants stepping on the arch-shaped obstacle with b the contralateral sound limb, and c–f the prosthetic limb, when using c, e their own prosthesis (Triton by Ottobock), and d, f the SoftFoot Pro. The top row displays the participant stepping on the obstacle from a static position, to show the change in shape of the sole of the SoftFoot because of the obstacle, resembling the human foot, contrary to the carbon foot. The bottom row, instead, shows the participant’s performance on the obstacle while walking. Images of the bottom row come from an overlay of the 3D marker data onto 2D videos in the software Vicon Nexus. Coloured links denote the reconstructed body segments based on the 3D markers trajectories from Vicon, with the GRF vector displayed in yellow.