A PT Explains Why Your Feet Go Numb When You Run

Everyone’s familiar with the numbness and tingling that comes when your foot “falls asleep.” But when foot numbness strikes while running, it can move past an annoyance and become a hindrance. What can cause foot numbness on the run, and what can be done about it?  Let’s unpack a few of the possible causes below.

Morton’s Neuroma

Small plantar nerves run between the bones and joints of the forefoot, supplying sensation to the toes. Anything that compresses the ball of the foot, including repetitive use like running, can cause swelling and scar tissue buildup around these nerves, leading to Morton’s neuroma. Symptoms include numbness, burning, and the sensation of walking on a pebble, with the third and fourth toes most commonly afflicted.

Treatments for Morton’s neuroma

Morton’s neuroma is treated by decreasing pressure on the nerve. Athletes should look for running and cycling shoes with wide toe boxes. They should also avoid narrow or high-heeled shoes in daily life. Orthotics for support and metatarsal pads that splay the forefoot apart can also help. Injections are an option, although these run the risk of weakening surrounding tissues. In stubborn cases, surgery to release the tissue around the nerve or remove the impacted portion can be performed.

Tarsal tunnel syndrome

The tarsal tunnel is a small space that sits behind the medial malleolus (inner ankle bone), where several tendons, blood vessels, and the posterior tibial nerve pass between the underlying bone and overlying connective tissue. Compression of the nerve in the tunnel leads to numbness, tingling, and pain in the bottom of the foot. Causes are typically related to inflammation from some sort of trauma, such as ankle sprains or acute tendinopathies. Because of the tunnel’s location, a more pronated foot combined with rapid increases in training can also induce symptoms.

Treatments for tarsal tunnel syndrome

Orthotics can help by decreasing strain on the tarsal tunnel. Strengthening the foot and ankle muscles, particularly those that support the arch, is important. Taping can help. In more recalcitrant cases, injections or surgery to release the nerve may be necessary.

Other nerve entrapment

The nerves that supply the feet start off from the sciatic nerve, which originates from the lower back, travels through the buttocks and down the back of the thigh, and splits just above the knee, with one portion continuing down the calf and the other wrapping around to the front and side of the lower leg. Compression anywhere along this path can cause numbness, with common areas of entrapment in triathletes at the spine and within the deep gluteal space in the buttocks.

Treatments for nerve entrapment in foot

Treatment for nerve entrapment involves first identifying the main point of compression using history, clinical tests, and nerve conduction studies or other imaging as needed. Lifestyle changes to minimize nerve compression (such as avoiding prolonged sitting) may be employed, and physical therapy to address underlying impairments and mobilize nerve and connective tissue is important. In severe cases, surgery may be indicated.

Shoes/laces too tight

Feet are complex structures, with many bones, tendons, ligaments, blood vessels, and nerves packed into a tight space. Adding more compression in the form of poorly fitting or tightly tied shoes can easily pinch off nerves and blood vessels, particularly those on the top of the foot, and cause numbness.

Treatments for shoe compression

Make sure that your shoes fit!  The toe box of your shoe should be wide enough to allow for proper splay of your toes, and laces shouldn’t be tied too tightly. Different lacing methods, such as skipping eyelets, can also decrease pressure on the top of the foot and alleviate symptoms.