This bone is the outside ray of the foot. The bunionette that develops is actually a response to the pressure from the shoe on the head of the fifth metatarsal. At first the bump is made up of irritated, swollen tissue that is constantly caught between the shoe and the bone beneath the skin. As time goes on, the constant pressure may cause the bone to thicken as well, creating an even larger lump to rub against the shoe. Causes Today a bunionette is most likely caused by an abnormal bump over the fifth metatarsal head rubbing on shoes that are too narrow.
Some folks have a widening of the foot as they grow older, until the foot splays .
This can cause a bunion on one side of the foot and a bunionette on the other if they continue to wear shoes that are too narrow. The constant pressure produces a callus and a thickening of the bursa over the bump, leading to a painful knob on the outside of the foot. Many problems that occur in the feet are the result of abnormal pressure or rubbing. A simple way of understanding what happens in the foot due to abnormal pressure is to view the foot simply. Our simple model of a foot is made up of hard bone, covered by soft tissue, that we then put a shoe on top of.