Bunions are a common and painful deformity of the joint of the big toe. They look like a “bump” at the base of the toe, and they are progressive. Over time a bunion can become so painful that is might be difficult to wear a shoe. It can also progress to the point that the big toe bends towards the toe next to it, crossing under it and affecting balance. This can lead to falls and cause major injuries. The good news is that bunions can be treated and may be avoided by following a few guidelines.

What are Bunions?

A bunion is an enlargement or protrusion of the joint at the base of the big toe.  This joint, metatarsophalangeal (MTP), is the big joint or “knuckle” of the big toe.  When we walk, we put tremendous stress on this joint as we push forward to the next step through the force of the big toe and two adjacent toes. The MTP joint should experience straight flexion/extension during a normal gait, but for many people, the anatomical alignment of the bones of the foot cause the MTP joint of the big toe to experience a twisting and side-bending action. Over time, this can cause damage that leads to bunions.

Many times bunions are found throughout the generations of a family.  The bunion itself is not inherited, but the foot type and anatomy of the foot is passed down from one generation to another. The flat foot is the most common type of foot associated with bunion development.  In most instances a person’s foot that “flattens” completely when they weight bear on the involved foot has an anatomical alignment of the metatarsal heads that is known as a forefoot varus. This foot anatomy produces excessive pronation during gait.  The varus alignment occurs when the anatomy of the foot is aligned with the metatarsal heads angled with the toe next to the big toe (2^nd metatarsal) and finishing with the little toe where the 2^nd metatarsal is elevated and the others are in descending order.

During gait, the 2^nd and 3^rd metatarsal heads have difficulty making contact with the ground when the foot is in a varus position.  The big toe helps to “pull” these two bones to the ground, but in doing so the big toe’s MTP joint is compromised and twists and bends into a valgus alignment.  The valgus alignment moves the two bones (proximal and distal phalanx) of the big toe towards the direction of the little toe and the metatarsal head in the other direction. This torque occurs with every step and over time it takes its toll on the structure of the joint and leads to the development of the bunion.

Bunions can also be cause by foot injuries, congenital deformities, arthritis, and neuromuscular disease.  One of the most common causes of bunions is the use of poorly designed shoes. Many fashionable shoes are not kind to the anatomy of the foot.  When heels are worn the there is an increased amount of pressure on the forefoot (the metatarsal heads of the foot). As the heel gets higher, the pressure increases significantly. Most high-heeled shoes have a narrow toe box that forces the forefoot and toes to be crammed into the front of the shoe. The average female forefoot is approximately 3+ inches in width while the average toebox is less than 2 ¾ inches. “Cramming” the front of the foot into such a small width can lead to permanent changes in the foot anatomy. People who wear “heels” on a regular basis commonly suffer from bunions after they turn 40.

Treating Bunions

The treatment for bunions is primarily based on controlling the pain with ice, NSAIDs and modalities to reduce the inflammation of the damaged soft tissue and joint structure.  Orthotics, exercises and sometimes surgery also play key roles in treating bunions.

Orthotics – The Physical Therapist can fabricate custom orthotics that can change the arthrokinetics (the movement of the bones) of the foot.  The custom orthotic can greatly reduce the stress on the metatarsal head of the big toe by controlling the forefoot varus alignment of the adjacent metatarsal heads.

Exercises – The Physical Therapist can also help mobilize the joint through certain exercises that target the entire kinetic chain (entire leg). These can help reduce the amount of leg and foot motion during gait which helps to reduce the stress that develops on the joints of the foot when someone is weight bearing and moving.

Surgery – Unfortunately, there are times that a surgeon must “correct” the alignment of the first metatarsal and big toe by performing a bunionectomy.   Physical therapy after surgery involves reducing swelling and pain and regaining the motion, proprioception and strength throughout the entire core and lower extremity.

Bunions are a deformity of the joint of the big toe and can occur naturally due to the anatomy of the foot or from wearing poorly designed shoes.  The pain that develops is a result of the inflammatory process with in the joint and soft tissues of the MTP joint of the big toe and can ultimately make walking and wearing a shoe nearly impossible.  Proper shoe wear, custom orthotics and certain exercises might enable a person to avoid developing a bunion.