Figure 3

Plantar tissue spreading analysis methodology. A/P and M/L shear forces from a representative participant are shown, plotted against time normalized stance phase. Directional shear forces are calculated from stresses multiplied by sensel area and summed by direction (i.e. posterior separate from anterior, medial separate from lateral). Net forces are also shown for reference. The A/P spreading force was extracted at midstance, where the net force crossed zero—this is the location of maximum spreading (i.e. opposing) shear forces. Spreading was quantified by the anterior or posterior (equal to each other) force at this point. The M/L spreading force was extracted as the mean lateral force (which opposes the primary medial force) across stance.