What is it?

Strictly speaking, "shin splints" refers to pain along the shin or front of the leg. However, many patients come into a physician's office complaining of "shin splints" when they have pain in the legs associated with running sports.

It is possible to have walking induced leg pain from atherosclerosis (hardening of the arteries to the legs) in older patients, so-called intermittent claudication. But in our context, we will confine the discussion to leg pain in children and young adults who are otherwise healthy, which comes on with running sports.

What causes it?

There are many causes of exercise related leg pain, but the common causes are as follows.

1. Stress Fracture in the tibia. This often occurs at the start of training season, when the athlete jumps into a heavy training schedule of running. The pain is localized to the front of the leg at the point of the stress fracture, commonly at the junction of the upper 2/3 and lower 1/3 of the tibia. X-rays may not show the fracture initially, and the only way to confirm that is to get a Bone scan which will reveal the "hot" area at the fracture site. However, over the course of 10 to 14 days, as healing starts to occur, the fracture becomes obvious on X-ray. Treatment consists of protecting the fracture with functional brace, as well as abstention from running for 6 to 8 weeks. The athlete can stay conditioned by swimming instead of running. After 8 weeks, if good healing occurs as evidenced by X-rays and lack of pain on walking with the brace, stretching and strengthening exercises are instituted. Impact activities are then gradually reintroduced until the athlete can resume full sports in about 12 weeks. Prevention of stress fracture is by having a training schedule year-round, and graduating the frequency and duration of training at the start of the season.

2. Chronic Exertional Compartment Syndrome. The muscles of the leg are enclosed in 4 compartments within the leg - the anterior, lateral, posterior superficial, and posterior deep compartments. Each compartment is bound by thick fibrous tissue called fascia that surrounds each group of muscles completely. During exertion, muscle volume in the leg increases by 20%, and that raises the pressure within the muscle compartment. In some individuals, this causes abnormal pressure in the compartment that may cause compression of the blood vessels and nerves in the compartment, leading to muscle pain due to anoxia, and tingling in the foot due to nerve compression. Typically, the anterior (front) compartment is affected, and causes pain in the front of the leg that comes on with running for a distance, and disappears with rest. Treatment consists of reducing the frequency and duration of training, use of non-steroidal anti-inflammatory agents and ice. If pain does not improve, or if the athlete is not willing to cut down on his activities, surgery consisting of dividing the fascia surrounding the muscle group often helps.

3. Periostitis of the tibia. This condition causes pain along the postero-medial margin of the tibia, and is due to overexertion, causing microtears of the muscle from the periosteum (covering) of the tibia. This is a form of overuse syndrome, and is best treated by relative rest, i.e., reducing the frequency and duration of running. Non-steroidal anti-inflammatory drugs are helpful. Graduated return to full sports is usually possible after 3 weeks.

4. Sprains/Strains of the leg. A sprain is a partial tear of a ligament or tendon. A strain is a partial tear of a muscle. This is a very common cause of leg pain. Ligament sprains of the knee and ankle are common. So are sprains of the tibialis posterior tendon and tibialis anterior tendon. Strains of the Gastrocnemius and Soleus muscles are common in runners. Treatment includes rest, bracing, NSAID's, Phycical therapy and graduated return to sports.