Fig. 4
From: Understanding patient preference in prosthetic ankle stiffness
Gait biomechanics at different stiffnesses and speeds. Lines represent inter-subject average trajectories across all experimental subjects. Line shade indicates VSPA stiffness (darker is stiffer). Only the preferred stiffness trajectory is shown for the slow and fast speeds. For all joints, the positive direction is extension (ext.)/dorsiflexion (d.f.) and the negative direction is flexion (flex.)/plantar flexion (p.f.) All trajectories are time-normalized to percent gait cycle