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Pain in the ball of the foot is called metatarsalgia and may have many different causes (including arthritis, poor circulation, pinching of the nerves between the toes, posture problems, and various disorders). However, most often the pain is caused by nerve damage or by an abnormality of the joints nearest the balls of the feet (metatarsal joints). Often, developing one disorder that causes pain in the ball of the foot contributes to development of another disorder that causes pain in the same location.
Freiberg Disease
Freiberg disease is tissue death (necrosis) of parts of the bones in the ball of the foot, usually the digit next to the big toe (the second metatarsal head).
The cause is injury to the bone, usually in girls who are going through puberty and who are growing rapidly or people in whom the bone connected to the base of the big toe is short. In both cases, the second metatarsal head can be subjected to repeated stresses.
Pain is usually worse when bearing weight, particularly when pushing off of the foot, or when wearing high-heeled shoes. The joint may be swollen and stiff. Doctors examine x-rays to confirm the diagnosis. Pain may be relieved with injections of corticosteroids and by using a splint or cast. Low-heeled shoes or inserts or other devices placed in the shoe that change the position or range of movement of the foot to relieve pressure on the affected joints or painful areas (orthoses) are helpful.
Damage to the Nerves in the Foot
(Interdigital Nerve Pain; Morton Neuroma)
Irritation of interdigital nerves (in the balls of the feet) may cause enlargement of the nerves, causing pain in the balls of the feet.
Causes
The nerves that supply the bottom of the foot and toes (interdigital nerves) travel between the bones of the toes. Pain in the ball of the foot may be caused by longstanding irritation of the nerves. The irritation often causes noncancerous (benign) growths of nerve tissue (neuromas) to form, usually between the base of the third and fourth toes (Morton neuroma). However, these growths may occur between any of the toes. Neuromas usually develop in only one foot and are more common among women. Many factors contribute to nerve irritation, including thinning of the fat around the nerves, poor foot posture, and nonsupportive or poorly fitting shoes.
Symptoms and Diagnosis
In the early stages, a neuroma may cause only a mild ache around the third or fourth toe, occasionally accompanied by a burning or tingling sensation in the toes, particularly as the disorder progresses. These symptoms are generally more pronounced when a person wears certain types of shoes, especially those that are too narrow for the front part of the foot, including those that are pointed. As the condition progresses, a constant burning sensation may radiate to the tips of the toes, regardless of what shoes are worn. A person may also feel as if a marble or pebble is inside the ball of the foot.
Doctors diagnose the condition by considering the history of the problem and examining the foot. X-rays, magnetic resonance imaging (MRI), and ultrasonography cannot accurately identify this disorder but may be helpful in ruling out other disorders that can cause similar symptoms.
Treatment
Injecting the tender spot in the foot with a corticosteroid/anesthetic mixture and wearing proper shoes and sometimes orthoses may relieve the symptoms. Rest and applying ice may also be recommended. Repeating the injections at intervals of 1 or 2 weeks may be necessary. Sometimes cryotherapy (application of cold) or injection of alcohol into the neuroma may also relieve pain. If these treatments do not help, surgical removal of the neuroma often relieves the discomfort completely but may cause permanent numbness in the area.
Metatarsal Joint Pain
Pain in the joints near the ball of the foot (metatarsophalangeal joint) may originate within the joints themselves.
Causes
Metatarsal joint pain commonly results from misalignment of the joint surfaces, which puts pressure on the joint lining and destroys cartilage in the joints. Mild heat and swelling may be present.
Metatarsophalangeal joint misalignment can also be caused by disorders, such as rheumatoid arthritis, that inflame the joints. In rheumatoid arthritis, hammer toes (see Foot Problems: Hammer Toe) can develop, which can worsen joint pain and misalignment. Fat tissue, which helps cushion the joints when bearing weight, can be pushed forward under the toes, resulting in a loss of cushioning in the ball of the foot. This loss of cushioning normally occurs as many people age but makes people more susceptible to pain when the ball of the foot is stressed or injured repeatedly (for example, by running or by walking excessively).
Metatarsophalangeal joint pain can also result from osteoarthritis or stiffening of the joints of the ball of the foot, often at the big toe joint. Most people with these disorders have an abnormal motion of the foot when bearing weight and walking.
Symptoms and Diagnosis
Walking is painful. Over time, pain and stiffening can be disabling.
Doctors usually can diagnose the disorder based on the person's symptoms and an examination, although testing is done if an infection or arthritis is suspected.
Treatment
Orthoses usually provide effective treatment. Shoes that have thicker soles than normal and rounded heels (called rocker-sole modifications) also help reduce pressure and abnormal motion. Occasionally, when these measures are ineffective, surgery is needed.
Sesamoiditis
Sesamoiditis is pain around a small bone (the sesamoid) below the metatarsal head where it adjoins the big toe (first metatarsal head).
The cause of sesamoiditis is usually repeated injury. Sometimes the bone is fractured, or the bone or surrounding tissues are inflamed. Sesamoiditis is particularly common among dancers, joggers, and people having high-arched feet or frequently wear high heels.
The pain of sesamoiditis is felt beneath the ball of the foot at the big toe and is usually made worse by walking, particularly when wearing certain thin-soled, flexible, or high-heeled shoes. The area may be warm or swollen.
The doctor bases the diagnosis on an examination of the foot. The diagnosis may be confirmed by x-rays taken to rule out a fracture of the sesamoid bone.
Avoidance of shoes that cause pain may be sufficient. If symptoms persist, however, shoes with a thick sole, low heels, orthoses, or a combination can help by reducing pressure on the sesamoid bone. A nonsteroidal anti-inflammatory drug (NSAID) taken by mouth and injections of a corticosteroid/anesthetic mixture into the affected area can help relieve pain.
Last full review/revision December 2012 by Kendrick Alan Whitney, DPM
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