Foot Callus (Hard Skin)
When we walk or stand, our body weight is carried first on the heel and then on the ball of the foot, where the skin is thicker, to withstand the pressure. When this pressure becomes excessive, some areas of the skin thicken, in the form of corns and callus, as a protective response.
A callus, or callosity, is an extended area of thickened skin on the soles of the feet, and occurs on areas of pressure. It is the body's reaction to pressure or friction, and can appear anywhere the skin rubs against a bone, a shoe, or the ground.
Most calluses are symptoms of an underlying problem like a bony deformity, a particular style of walking, or inappropriate footwear. Some people have a natural tendency to form callus because of their skin type. Elderly people have less fatty tissue in their skin and this can lead to callus forming on the ball of the foot.