There are many different causes of sore feet affecting such a large percent of the population. One not so common cause is a enlarged bone on the side of the arch area of the foot is frequently an accessory navicular. The navicular bone is a bone at the top of the mid-foot in the middle, shaped somewhat like a banana. On the side of the on the arch area it can be prominent or may have an additional piece of bone alongside it. This prominent bone or additional piece of bone can be painful as a result of pressure from the shoes. Situations in which it can be particularly painful is in sports like ice skating when the enlargement of the bone pushes on the very hard footwear that is used. This is often very painful. Another issue, as a result of enlargement is that the tendon isn't as powerful as it should be and a flattening of the arch might occur.
Treatment choices for an Accessory Navicular is determined by the judgment of the treating podiatrist and exactly how you get the symptoms. If the symptoms are as a result of the size of the lump on the shoe, then padding in the shape of a donut may be used to protect the spot. If that is not really beneficial then surgical excision of the extra bone is required. This isn't as easy as cutting off the bone, as the tendon needs to be taken off initially and then the acessory bone removed and then the tendon has to be reattached. If the pain is as a result of the muscle and tendon unit not working effectively and a flat foot is the result, this is best treated initially with foot orthoses. If that is not helping, then surgery might be needed. The option of treatment will depend on the actual cause of the symptoms, the age and activities of the individual with the problem and what the required result is.