Callus Formation Foot Callus and corns are extremely common on our feet. A thin layer of flexible callus is a healthy protective barrier of the skin. Corns however do not have any benefit and can be immensely painful. Here is information and advice on these two common complaints. Callus Callus is thickened, hard skin developed from friction. Common areas to find these on the feet are: Lateral (outside) of the 5th toes Tips of the toes Medial (towards midline of the body) of the big toe joints Under the metatarsophalangeal joints (balls of the feet) Heels The above areas of the foot tend to experience the most pressure and friction. Points 1 & 2 are signs that your footwear should be wider and longer. If your shoes are narrow, they will create friction on the sides of the 5th toes. If your toes butt up against the end of your shoe, you can develop callus on the apices of the toes. Point 3 is mechanically induced, often seen in runners or people who may require orthotics (insoles) to improve foot function. The plantar metatarsophalangeal joints (point 4) take a high amount of pressure and friction, as we use this area to 'push off' when walking or running. Sports that involve pivoting and change of direction such as netball, basketball and tennis tend to exacerbate this. Heels (point 5) are involved when we make contact with the ground, and take the initial shock absorption. Heel contact generally moves from the lateral (outside) towards the medial (inside) during gait, and