Metatarsalgia
Definition:
Metatarsalgia is the medical term used to describe pain and inflammation in the ball of the foot. The metatarsal bones are five long bones in the forepart of the foot that connect the arch with the toes. When pushing off to take a step forward, or when landing from a jump, the full weight of the body is distributed amongst these bones. The joints formed at their connection with the tarsal bones, and with the phalanges, or toe bones, are held in proper alignment by ligaments. Tendons attach muscles to the bones, and the ball of the foot is supplied with nerves and blood vessels. There is a pad of protective, shock-absorbing fatty tissue between these structures and the skin. A disruption, imbalance, or weakness in the normal structure of the foot can lead to metatarsalgia.
Causes:
A change in the distribution of weight on the metatarsals increases pressure on the bones, particularly the heads of the bones that connect with the toes. When a metatarsal head is pushed downwards, below the level of the other metatarsal heads, it is subjected to the full weight of the body at each step. Such abnormal pressure will eventually induce a painful inflammatory response.
Often, several factors combine to produce metatarsalgia. These can include:
- Foot shape: a high arch to the foot, an unusually long second toe, or very long metatarsals
- Being overweight, which would increase pressure on the ball of the foot
- Being very active, particularly in sports that involve running or jumping
- Wearing shoes that fit poorly, have small, tight toe boxes, high heels, or thin soles
- Foot conditions such as a bunion that can weaken the big toe and increase pressure on the ball of the foot, or a hammertoe, where one toe curls downwards and depresses the metatarsal head.
- Stress fractures, which are tiny breaks in the bone, causing a shift in weight distribution
- Conditions such as diabetes, arthritis, Freiberg’s disease, or Morton’s neuroma
- Thinning of the fat pad: thinning can be caused by the normal aging process, by a dropped metatarsal head which gradually pushes the fat out of position, by extra pressure from wearing high-heeled or thin-soled shoes, or by some medical conditions
- Bruising of the sesamoid bones at the base of the big toe
- Nerve damage between the toes
Symptoms:
Symptoms usually develop gradually, but sometimes there can be a sudden onset of pain.
- Pain, ranging from mild to severe and from aching to sharp, in the ball of the foot
- Shooting pain, numbness or a tingling sensation in the toes (indicates nerve damage)
- Pain in the ball of the foot near the big toe
- Pain in the ball of the foot near the second, third, and fourth toes
- Pain worse with pressure on the foot, and better with rest
- Pain worse when walking barefoot, and when walking on a hard surface
- Severe pain when pressing hard with your thumb on the head of your big toe (indicates damage to sesamoid bones)
Diagnosis:
Due to the fact that many foot problems can cause symptoms of metatarsalgia, diagnosis will probably involve having an x-ray taken, as well as a thorough physical examination of the foot. You may be asked to stand and walk so the doctor can assess your posture and weight distribution on the foot. You will also be asked questions about your activities, any sports you may participate in, and your general lifestyle.
Treatment:
Conservative (non-surgical) treatment usually relieves metatarsalgia. Your doctor will probably advise you to try one or more of the following:
Rest the foot by avoiding activities that place undue pressure on the ball of the foot. You can still exercise, but limit this to low-impact activities such as swimming or bicycling, and strength training.
Ice the foot by crushing ice in a bag and covering it with a towel then placing the bag under the ball of your foot. Keep your foot on the ice for as long as is comfortable, several times a day.
Over the counter pain medication such as acetaminophen (Tylenol), ibuprofen (Advil), or naproxen (Aleve) can help with pain and inflammation.
Wear shoes that are properly fitted, both for sports and daily activities.
Use insoles, metatarsal pads or arch supports in your shoes. Several over the counter options are available. Insoles act as shock absorbers, metatarsal pads deflect pressure away from the ball of the foot, and arch supports assist by reinforcing the arch, thereby relieving pressure on the metatarsal bones. Custom made orthotics may be necessary for your particular foot, but these are expensive and it may be worth trying ready-made orthotics first.
If metatarsalgia is being caused by Freiberg’s disease, nerve damage, or inflammation around the sesamoid bones, pain can sometimes be reduced by an injection of cortisone into the affected area. Such injections can provide long-lasting pain relief, but can only be administered a few times a year.
Rarely, surgery to realign the metatarsal bones is required. As with all surgery, there are both risks and benefits to be weighed before a decision is made. Surgery normally involves cutting through the metatarsal bone and pinning it into its corrected position.
Prevention:
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