On a larger scale sciatica, piriformis syndrome and other maladies, can cause a numbness in the foot that can take much longer to go away and in some cases never go away. If the sciatic nerve gets impinged at any point on its way from the spinal cord to the foot its effectiveness will decrease. Think of a water hose that you put a crimp into.
A callus (or callosity) is a toughened area of skin which has become relatively thick and hard in response to repeated friction, pressure, or other irritation.Rubbing that is too frequent or forceful will cause blisters rather than allow calluses to form.ormally, a callus will form on any part of the skin exposed to friction over a long period of time. For example, people often develop calluses on the middle finger of their dominant hand due to writing with a pen or pencil.
The skin or epidermis is the external protective layer of the integumentary system. Skin provides protection against injury from the external environment. Direct pressure and friction forces can create thickening of the skin eventually leading to the development of a callus. Callus is a protective response of the skin to prevent injury. Thickening of the callus over time can lead to the development of pain.