Metatarsalgia

INTRODUCTION

Background

Metatarsalgia is a common overuse injury. The term describes pain and inflammation in the ball of the foot. It is often thought of as a symptom of other conditions, rather than as a specific disease.

Frequency

In the United States, forefoot injuries, including metatarsalgia, are common in athletes who participate in high-impact sports.

Athletes who take part in high-impact sports involving running or jumping are at high risk of forefoot injury. While track and field runners are exposed to the highest level of traumatic forces to the forefoot, many other athletes, including tennis, football, baseball, and soccer players, often have forefoot injuries.

SYMPTOMS AND CAUSES

The primary symptom of metatarsalgia is pain at the end of one or more of the metatarsal bones. The pain is typically aggravated when walking or running. Athletes with combinations of high-impact inflammatory conditions often have diffuse forefoot and midfoot pain.

Most often, the pain comes on gradually, for example over a period of several months, rather than suddenly.

A condition known as Morton's neuroma (interdigital neuroma) produces symptoms of metatarsalgia due to irritation and inflammation of nerves. People with Morton's neuroma may experience toe numbness in addition to pain in the forefoot..

Causes

The foot frequently is injured during sports activities. As with many other overuse injuries, the condition may be the result of an alteration in normal biomechanics that has caused an abnormal weight distribution.

Persistent stress can lead to chronic irritation and inflammation of the bone covering and adjacent tissues.

The following factors can contribute to excessive localized pressure over the forefoot:

• High level of activity
• Prominent metatarsal heads
• Tight toe extensors (muscles)
• Weak toe flexors (muscles)
• Hammertoe deformity
• Hypermobile first ray
• Tight Achilles tendon
• Excessive pronation (side-to-side movement of the foot when walking or running)

Some anatomical conditions may predispose individuals to forefoot problems. They include:

• A high arch with stress to the forefoot often causes pain in the metatarsal region.
• Individuals with a Morton toe have a short first metatarsal bone. The normal forefoot balance is disturbed, resulting in the shift of an increased amount of weight to the second metatarsal.
• Hammertoe deformity causes metatarsalgia because the top of the shoe pushes the toe down, depressing the metatarsal heads.

Any or all of the above musculoskeletal problems may contribute to forefoot trauma in athletes.

EVALUATION

X-rays may be helpful in excluding other causes of forefoot pain.

Serially repeated radiographs and/or a bone scan may assist the doctor with diagnosing or excluding a metatarsal stress fracture.

Ultrasound can help identify conditions such as bursitis or Morton neuroma that can be causing pain in the metatarsal region of the foot.

The doctor may also ask for an MRI to help detect and diagnose many causes of pain in the metatarsal and midfoot regions. These can include traumatic disorders, circulatory conditions, arthritis, neuroarthropathies, and conditions that result in biomechanical imbalance.

The doctor may also ask for other tests and procedures to help in the diagnosis and in determining the proper treatment.