There are a lot of causes of foot pain Plantar fasciitis, heal spurs, stress fractures, mid foot sprains.  Another cause many don’t think about is Morton’s neuroma.  Classically patients describe it feels like “walking on a marble,” is usually a persistent pain in the ball of your foot, usually between the 3rd and 4th toes.

Morton’s neuroma is not actually a tumor, but a thickening of the tissue that surrounds the digital nerve leading to the toes.

 

From the orthopedic association,

Exam
During the examination, your physician will feel for a palpable mass or a “click” between the bones. He or she will put pressure on the spaces between the toe bones to try to replicate the pain and look for calluses or evidence of stress fractures in the bones that might be the cause of the pain.
Treatment
Initial therapies are nonsurgical and relatively simple. They can involve one or more of the following treatments:

Changes in footwear. Avoid high heels or tight shoes, and wear wider shoes with lower heels and a soft sole. This enables the bones to spread out and may reduce pressure on the nerve, giving it time to heal.
Orthoses. Custom shoe inserts and pads also help relieve irritation by lifting and separating the bones, reducing the pressure on the nerve.
Injection. One or more injections of a corticosteroid medication can reduce the swelling and inflammation of the nerve, bringing some relief.
Several studies have shown that a combination of roomier, more comfortable shoes, nonsteroidal anti-inflammatory medication, custom foot orthoses and cortisone injections provide relief in over 80 percent of people with Morton’s Neuroma. If conservative treatment does not relieve your symptoms, your orthopaedic surgeon may discuss surgical treatment options with you. Surgery can resect a small portion of the nerve or release the tissue around the nerve, and generally involves a short recovery period.

 

Source: Morton’s Neuroma-OrthoInfo – AAOS