A callus is an area of thickened skin tissue on the bottom of the foot due to irritation and friction, typically under bony prominences. The patient feels pain in the area of the callus, especially when there’s direct pressure.
The integrity of the protective barrier the skin provides the foot is critical in maintaining weight bearing function. Callus formation occurs in areas of high vertical and shear loads and defends against blistering and ulceration. However, this process itself can cause symptoms and predispose patients with poly-neuropathy to deep infection. Even when considering a ‘healthy’ foot, poor foot function can lead to callus formation. During over-pronation, the foot rolls across the metatarsal heads – one at a time – instead of distributing the weight equally. This happens because the foot is a “loose bag of bones” during pronation causing hypermobility of soft tissues. When the “loose bag of bones” phase goes on too long and the skin is trapped between the bones in the foot and the ground, the friction of individual metatarsal heads bearing all the weight can cause inflammation.
The skin thickens in the inflamed area to protect the sore spot. This thick build up of skin so close to the nerve endings in the bottom of the foot is what causes the pain. This callus formation is our body’s defense mechanism to protect the foot against excessive pressure and friction. Calluses are normally found on the ball-of-the-foot, the heel, and/or the inside of the big toe.
Many people try to alleviate the pain caused by calluses by cutting or trimming them with a razor blade or knife. This is not the way to properly treat calluses. This is very dangerous and can make the condition worse, resulting in unnecessary injuries. Diabetics especially should never try this type of treatment.
In order to relieve the excessive pressure that leads to callus formation, weight should be redistributed equally with the use of an orthotic insert. An effective insert transfers pressure away from the “hot spots” or high pressured areas to allow the callus to heal. The insert should be made with materials that absorb shock and shear (friction) forces. Women should also steer away from wearing high-heeled shoes.
Podiapro’s orthotic insoles are customized to redistribute weight away from the callus partially or fully. We have special module for corns and calluses that have medical poron as one of the layers, a material that is excellent for weight offloading.