The Anatomy of a Callus


The old saying, “A picture is worth a thousand words” so aptly applies while looking at this picture of the bottom of the foot.Thickened skin or callus on the bottom of the foot occurs because of high pressure and friction during walking. Although thought to be protective of the skin it can be quite painful if it builds up in excess. This picture shows three localized areas of callus that correlated to high pressure and friction.

The first callus located at the big toe joint is related to a bunion deformity and excessive foot pronation during walking. This “pinch callus” occurs due to the foot “rolling in” or pronating excessively during walking and the increased pressure and friction in the region when the heel lifts off of the ground.
The second callus is present on the bottom of the second metatarsal bone. Due to the altered position of the first metatarsal bone with the bunion deformity, the second metatarsal receives additional pressure and friction which occurs during the lifting of the heel during the walking cycle.
The third callus noted on the bottom of the fifth metatarsal bone occurs due to the high pressure and friction that occur and the relative prominence of this bone as it relates to the other four metatarsal bones.
Condition-specific orthotics reduce pressure and friction by controlling excessive foot pronation during walking. Strategically placed pads on the orthotic device reduce pressure and friction on the callus which helps reduce pressure and eliminate pain. By focusing on adequate shoe wear as well as a condition specific orthotic the callus will build up less quickly and even sometimes resolve.