Q: I have noticed that several of your readers have asked about numb toes. I have this issue on both feet after about 30 minutes of either biking or running, and I'm wondering if you have ever encountered or know anything about Morton's Neuroma. While trying to solve my issue, I've seen this malady on the internet, and seems like a likely suspect. Any feedback you can give on this would be greatly appreciated!
     --Michael Crouser

A: A neuroma is a thickening of a nerve due to repetitive trauma or chronic irritation. Morton’s neuroma involves one of the nerves that runs along a metatarsal in the foot and divides into two smaller nerves at the ball of the foot (metatarsal heads). The swelling in the nerve typically occurs between the metatarsal heads, causing a burning pain in the ball of the foot along with pain and/or numbness in the toes. This occurs most commonly between the third and fourth metatarsals, but may be present between the second and third metatarsals. The most common cause of the neuroma is compression from shoes that are too tight. This may be due to a toe box that is too tight or shoes that fit tightly due to thick socks or orthotics. Remember that the feet will swell during exercise, making shoes fit more tightly.

Treatment of this problem starts with ensuring the proper fit of all shoes. When purchasing shoes, wear your running socks and orthotics or other device that you may place in a shoe. Try on shoes later in the day when your feet may be swollen. With your current shoes, loosen the laces at the bottom (near the toe box). You may even consider an alternate lacing pattern to decrease the tightness in the toe box.

A metatarsal pad may help with the pain as it can relieve some of the pressure at the metatarsal heads. The pad is placed behind, not under the ball of the foot. The easiest way to properly place a pad is to mark each metatarsal head with lipstick and step on a shoe insert. The pad should be placed behind the marks. The insert may be placed in any shoe.

If pain persists, a cortisone injection may be helpful; recalcitrant pain may require surgical excision of the neuroma.

     --Dr. Cathy Fieseler