Section 5. Bone, Joint, and Muscle Disorders

Chapter 72. Foot Problems

Topics: Introduction | Foot Pain | Ankle Sprain | Tarsal Tunnel Syndrome | Plantar Fasciitis | Achilles Tendon Bursitis | Ingrown Toenail | Onychomycosis | Onychia | Corns and Calluses | Onychauxis and Onychogryphosis | Hallux Valgus and Bunion | Hammer Toe | Sesamoiditis

Foot Pain

Although any foot problem can cause pain, this chapter focuses on the most common locations for pain--the ball of the foot (the underside of the front end of the metatarsal bones--the metatarsal heads), the toe joint, and at a heel spur.

Pain in the Ball of the Foot

Pain in the ball of the foot may have many different causes (including arthritis, poor circulation, pinching of the nerves between the toes, abnormal metatarsal length and posture problems, and various diseases). However, most often the pain is caused by nerve damage or by an age-related change that affects the foot, called metatarsalgia.

Pain Caused by Damage to the Nerves in the Foot: The nerves that supply the bottom of the foot and toes travel between the bones of the toes. Pain in the ball of the foot may be caused by noncancerous (benign) growths of tissue (neuromas) wrapped around nerves, usually between the base of the third and fourth toes (Morton's neuroma), although these growths may occur between any of the toes. Neuromas usually develop in only one foot and are more common in women than in men.

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. 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 were 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 ultrasound cannot accurately identify this disorder.

Injecting the tender spot in the foot with corticosteroids mixed with a local anesthetic and wearing orthotics may relieve the symptoms. Repeating the injections two or three times at intervals of 1 or 2 weeks may be necessary. If these treatments do not help, surgical removal of the neuroma often relieves the discomfort completely but may cause permanent numbness in the area.

Pain Caused by Metatarsalgia: With age, there is a loss of the protective pad of fat that cushions the metatarsal heads. Pain at this location is called metatarsalgia. If untreated, the condition can cause inflammation to develop in the bursas that are situated below each metatarsal head (metatarsal bursitis). Rheumatoid arthritis can also cause pain and swelling at this location.

Treatment is by means of special shoes, cushioning, or orthotic devices that shift weight from the ball of the foot to more evenly distribute weight across the entire foot.

Toe Joint Pain

Pain involving the joints of the four smaller toes is a very common problem, usually caused by misalignment of the joints. This misalignment may result from high or low arched feet that cause the toes to stay in a bent position (hammer toes). Constant friction against the bent toes causes the skin over the joint to thicken, resulting in a corn. Treatment is directed at relieving the pressure caused by toe misalignment: Making the shoes deeper, applying protective sleeves or shields on the toes, placing pads in the shoes, surgically straightening the toes, and paring down the corn may help.

Chronic arthritis (osteoarthritis (see Section 5, Chapter 66)) at the base of the big toe (also called hallux rigidus) is extremely common. Certain factors, such as flat feet, a long big toe and a foot that rolls inward, are thought to predispose a person to hallux rigidus. When a person stands and walks with a foot position that lowers the arch, it may cause the foot to roll inward. This abnormal foot alignment is called pronation and is often responsible for the increased stress at the big toe joint that produces pain and osteoarthritis with limited motion in that joint. Occasionally, an injury to the big toe may also cause painful arthritis. Joint pain in the big toe is usually aggravated by wearing poor-fitting shoes or shoes that are too flexible, causing increased motion with pain at the big toe joint. Shoes with increased support and rigid soles may help. Later, a person may become unable to bend the big toe during walking. The area is not warm to the touch. This osteoarthritis is different from that occurring in gout, which can develop as severe pain at the same location, but the area is warm to the touch (see Section 5, Chapter 70).

Fitting the shoe with orthotic devices to correct improper foot motion and relieve pressure on the affected joints is the mainstay of treatment. Pain in the big toe that started recently may be relieved by toe traction and exercises that move and extend the joint. Injections of a local anesthetic can relieve pain and decrease muscle spasm so that the joint can move more easily, and a corticosteroid may also be injected to decrease inflammation. If these treatments are not successful, surgery to improve joint alignment and function may relieve the pain.

Heel Spur Pain

Heel spurs are growths of extra bones at the heel. They can result from excessive pulling on the heel bone by tendons or the connective tissue attached to the bone (fascia).

See the figure What Is a Heel Spur?

Heel spurs are common but typically do not cause pain. They cause pain when inflammation develops in adjacent tissues. Heel spur pain is also called plantar heel pain syndrome. The first symptoms of heel spurs are typically noticed when the person arises and puts the foot down first thing in the morning. They may also occur with the first few steps after sitting for a long time.

Usually, heel spur pain can be diagnosed during a physical examination. Pressing on the bottom of the heel where the arch begins usually causes pain. Pain with pressure to the center of the heel indicates that an inflamed bursa may also be present. X-rays may be taken to confirm the diagnosis, but results may be normal at first.

Treatment is aimed at relieving pain. Wrapping the foot and arch with padding and tape or using orthotics, which help to stabilize the heel, can minimize stretching of the fascia and reduce pain. Heel cushion pads and supportive shoes with soft soles may also help. Calf stretching exercises and ice massage are also effective. Ice massage consists of massaging an area of skin, using ice. One way to do this is to freeze water in a paper cup, then turn the cup upside down and rub the ice against the skin. As the ice melts, the paper is progressively peeled away. A mixture of corticosteroids and a local anesthetic can be injected into the painful area of the heel. Most painful heels spurs resolve without surgery.

Surgery to remove the spur or the dense band of tissue that extends from the spur at the bottom of the heel bone to the base of the toes (plantar fascia) should be performed only when constant pain is not relieved by other treatment measures. Surgery should be considered only as a last resort because the results are not predictable. Occasionally, pain persists after surgery.