Pressure distribution under the foot during static activities

The distribution of the ground-to-foot supportive forces at various sites under the foot during static leaning acts are reported in this study. A strain gage ring transducer assembly was constructed to measure the vertical loads under the five metatarsals, and the heel during forward leaning (tilting of the pelvis on the lower extremities) from the symmetric vertical stance. The distribution of the ground reactions appears to favor the lateral metatarsals with comparatively lower contribution by the structurally larger first metatarsal. The distribution, however, is greatly influenced by the placement of the foot on the transducers - reflecting sensitivity to change in the relative intersegmental geometry and the resulting force-transmission network internally. Similar changes are observed in the theoretically predicted pressure distribution pattern obtained by using a comprehensive three-dimensional foot model.