One often overlooked cause of lower leg pain is exertional compartment syndrome.
"ECS occurs when the pressure in the closed space of one of the five compartments of the lower leg becomes so great that it decreases the blood flow to the tissue in that individual compartment," says Dr. Brian Halpern, a sports medicine specialist at the Hospital for Special Surgery in Manhattan.
Each compartment is surrounded by an envelope called the fascia. "As the pressure increases dramatically within the compartment, the fascia acts as a noose around the muscles and nerves of that specific compartment," says Halpern. This can result in extreme leg pain and sometimes numbness in the leg or the foot.
The pain often occurs after the same amount of exercise, such as at mile three in a specific run.
"If you try to continue to run through the pain, it just becomes worse and more disabling," says Halpern. That part of the leg may feel hard to the touch. Shortly after the person ceases to exercise, the pain and tightness stop, only to return around the same mileage in any subsequent run. Resting usually relieves the discomfort completely.
The compartments most commonly affected are the front and outside of the lower leg. Suggested treatments include prescription foot orthodics, physical therapy, an altered running surface or a decrease in the problem activity. Surgery to decrease the abnormally high pressure in the leg is generally a last resort.