Figure 1
From: Adding Stiffness to the Foot Modulates Soleus Force-Velocity Behaviour during Human Walking
Adding stiffness to the foot altered the centre-of-pressure propagation during stance and decreased net mechanical work due to foot deformation.
(a) The centre-of-pressure (COP) during stance was expressed in the foot’s sagittal plane (N = 20). Each circle corresponds to averaged COP data for one percent of stance. The position of the ankle joint in the foot’s reference is denoted by the diamonds. A vertical projection of the metatarsal-phalangeal joint in the foot’s reference frame is denoted by the dashed vertical grey lines. (b) The foot deformation power was time-normalized to the stride cycle (N = 20). Three distinct phases of power were evident: negative power immediately after heel strike, negative power during ~30–60 percent of stride and positive power before toe-off. (c) Total positive work, negative work and net work were quantified during stride (N = 20, means ± s.e.m). With added foot stiffness (ΔK), there was an increase in total positive work (p < 0.001), decrease in magnitude of negative work (p < 0.001) and decrease in magnitude of net work (p < 0.001). P-values indicate the main effect of added foot stiffness. **denotes significant pair-wise difference with respect to each of the other conditions. Square brackets show additional significant pair-wise comparisons.
