Sesamoiditis is painful inflammation of the sesamoid apparatus, which is located in the forefoot. It is a common condition that typically affects physically active young people. Sesamoiditis causes pain in the ball of the foot, especially on the inner (medial) side. The pain may be constant, or it may occur with or be aggravated by, movement of the big toe joint. It may be accompanied by swelling (edema) throughout the bottom (plantar aspect) of the forefoot.
Sesamoiditis is usually caused by repetitive, excessive pressure on the forefoot. It typically develops when the structures of the first metatarsophalangeal joint are subjected to chronic pressure and tension. The surrounding tissues respond by becoming irritated and inflamed. This is a common problem among ballet dancers and people who play the position of catcher in baseball. Any activity that places constant force on the ball of the foot—even walking—can cause sesamoiditis.
Damage to the sesamoid bone may also result in sesamoiditis. Stress fractures (microscopic tears in the bone structure due to repetitive abuse) can produce this condition.
Treatment for sesamoiditis is usually noninvasive. Minor cases require a strict period of rest and the use of a modified shoe or a shoe pad with a cutout to reduce pressure on the affected area. A metatarsal pad can be placed away from the joint to redistribute the pressure of weight bearing to other parts of the forefoot. In addition, the big toe may be bound with tape or athletic strapping to immobilize the joint as much as possible and allow healing to occur.