The Plantar Nerves
The nerves that run along the bottom of the foot extend from the inside of the ankle out to the tips of the toes. Each toe receives four nerves – two on top and two on bottom.

Each of these nerves on the bottom of the foot is susceptible to becoming pinched between the bones and ligaments in the foot and the ground. In the case of neuroma, a nerve on the bottom of the foot and between the toes is pinched and rubbed against a ligament. The nerve initially starts out becoming inflamed. The onset can be sudden or it may take weeks to develop. Over time, the constant inflammation of the nerve will evolve into scar tissue. The scar tissue creates a hard and unforgiving exterior band around the nerve and leads to chronic pain or numbness.

What are the symptoms?
Typically, the symptoms begin as a localized pain on the bottom of the foot at the base of the toes. This pain can range from a dull ache or throb to a sharp or burning sensation. At times, electrical shock type symptoms will occur. Patients will often describe feeling as though they are walking on a marble, knot or crease in the sock. Activity and weight bearing often aggravates these symptoms. Tight fitting, narrow, or high-heeled shoes tend to also aggravate the symptoms. In addition, climbing stairs, squatting, or kneeling can worsen the symptoms.

How do neuromas form?
To understand how neuromas form, think of a violin and bow. Much like a bow moves across the strings of a violin, the nerves in the ball of the foot stretch and move across a ligament between the bones on the bottom of the foot. If this movement or pressure becomes excessive, then the nerve will become inflamed. The nerve can also be pinched between the bones in the foot during walking, in tighter shoes, and with pressure from the ground. The inflammation around and within the nerve can alter the structure and function of the nerve over time. Scar tissue will replace the inflammation and lead to chronic and more severe symptoms.

How is a neuroma diagnosed?
Neuromas are typically diagnosed by a thorough clinical examination of the feet. The location, characteristics, and timing of the symptoms are important clues regarding the potential for a neuroma. At times, a palpable clicking sensation or noise can be recreated by squeezing the forefoot and pressing between the toes. An ultrasound or MRI have proven useful in helping to diagnose a neuroma and rule out other problems in the same region of the foot.

Can I continue to run if I have a neuroma?
Yes, but you should stop if the pain becomes consistent with every step or if the symptoms continue after resting following your run. Keep in mind, if the more your running injuries the nerve, the more permanent the symptoms and the less successful conservative treatment becomes. In the end, a prognosis for treatment and recovery is best accomplished with a clinical examination.

Are there ways to prevent a neuroma from forming?
Yes. There are several factors that contribute to neuroma formation and consequently, each of these factors can be independently addressed to prevent a neuroma from forming. Prevention begins with proper shoes. Shoes should never be narrower than the foot. This can be checked by tracing an outline of your foot while standing barefoot on a blank piece of paper. Then, simply set the shoe over this tracing to identify any difference in the width of your foot and shoe. Next, proper  flexibility of the calf muscles helps to prevent excess pressure in the forefoot. Arch supports are often helpful in spreading the pressure across the foot more evenly. In this manner, there is less pressure on any one nerve on the bottom of the foot.

What treatments are available?
Treatment begins with a conservative approach. The conservative treatment options are effective in about 68% of cases if care is sought early enough. Many of these treatments are listed on the following page of this brochure. When conservative treatment fails to provide adequate relief of symptoms, then surgery is an effective treatment option. Surgery involves destroying the nerve through a small device that cauterizes the nerve or removing the nerve. Although this leaves a small area of numbness on the ball of the foot, it is rarely noticed unless tested clinically. Most patients much prefer this small area of numbness to the constant pain of an inflamed or scarred nerve.

This information is not intended to diagnose, treat, or prevent any injury or disease. It is intended to serve as an overview of running-related injuries and should not be used as a substitute for sound medical advice from a doctor or therapist.