Exercise-Induced Compartment Syndrome

The muscles of the leg are located in distinct compartments which also contain arteries, veins and nerves. These compartments are separated by bone and fascia, a thin but tough sheet of connective tissue. Due to the strong nature of the bone and fascia, the size or volume of these compartments does not change during exercise.

What is a exercise-induced compartment syndrome?
The volume of a muscle can expand by up to 20% during exercise. Consequently, the muscle compartments in the leg must allow for the increased blood flow and increased size of the muscle tissue during exercise. Generally, venous and arterial blood flow is automatically adjusted by the body to keep the compartment pressure within a safe range. However, pain will occur if the compartment pressure increases beyond a safe limit. Rarely does more serious damage occur to muscles, nerves, and blood vessels.

What are the symptoms of an exercise-induced compartment syndrome?
Throbbing pain in the middle of the leg during exercise is the first symptom of an exercise-induced compartment syndrome.  Runners with this condition will typically complain that their leg feels swollen or stiff. In some cases, tingling, numbness, or a pins-and-needles sensation will occur in the leg and foot. Because there are several leg compartments, the exact location of pain will depend on which compartment is affected. Research has shown up to 45% of runners with exercise-induced compartment syndrome will notice the muscle herniating through the fascia – a semi-firm bump overlying the muscle in the leg. The symptoms generally take several minutes or longer to develop. Often runners can predict the onset because it generally occurs at about the same distance each time. These symptoms will resolve shortly after the exercise is stopped.

How is a compartment syndrome diagnosed?
The foundation for diagnosing exercise-induced compartment syndrome is a runner’s clinical history. The symptoms are often sufficient to establish the correct diagnosis. However, the exact diagnosis requires measurement of the intra-compartmental pressure. This is accomplished by using handheld device with a small needle that is inserted into the compartment. Pre-exercise, base-line measurements are obtained and then the runner is measured when the symptoms during exercise. This typically involves a treadmill run in the office. Rarely would a more specific imaging test such as MRI or CT be needed unless other problems are suspected.

How is exercise-induced compartment syndrome treated?
Treatment for exercise-induced compartment syndrome starts with optimizing the runner’s biomechanics. Although not the only cause, biomechanics are often a contributing factor in the development of exercise-induced compartment syndrome. Biomechanical treatment includes addressing mal-alignment in the legs and feet, the use of orthotics or wedges inside the shoes, and stretching to optimize flexibility. Foam rolling is an excellent way to increase flexibility and massage the muscle compartment and aid in reducing the compartment pressure. If muscle weakness or fatigue is present, that should be corrected as well. Cross-training can afford the muscles an opportunity to respond to exercise in a less predictable pattern and thus reducing the symptoms of exercise-induced compartment syndrome. In some cases, conservative treatment does not work and surgery is necessary. This involves a fasciotomy, or cutting of the fascia to reduce the pressure in the compartment. The skin is closed over the fasciotomy site and allowed to heal. This effectively increases the “volume” of the compartment.

Can I continue to exercise with exercise-induced compartment syndrome?
Whether it is safe to continuing running depends on the severity of the symptoms. Those with milder symptoms can continue running while they address those factors mentioned above. When symptoms become more severe and stop a runner from completing their training, it may be necessary to reduce the training load, to cross-train, or some cases take time away from running. This is especially important for runners who experience neurological symptoms such as tingling, numbness, or pins-and-needles in the legs and feet. Deep water running is a simple way to keep the running muscles working but without the load of weight bearing. This is easy to accomplish with any type of floatation device to hold you up in a pool while your legs perform a running motion. Anti-gravity treadmills are available in some locations, but they tend to be expensive to use and hard to find. Upper extremity and core work will provide you with an opportunity to enhance the fitness and strength of areas often neglected with traditional running programs. In the end, always remember with every adversity comes opportunity.

When can I return to running?
The goal of rehabilitation is return you to running as soon as is safely possible. If you return to a full training load too soon, the symptoms may return. Everyone recovers from injury at a different rate, so don’t compare your rehabilitation to other runners. Returning to running is determined by how well your leg responds to treatment rather than a set number of days or weeks. Here are some general guidelines for a full return to running.

• You should be able to jog in a straight line without limping.
• You should be able to sprint without limping.
• You should be able to perform 45-degree and 90-degree cuts without difficulty.
• You should be able to jump on the injured leg without pain.
• You should be able to complete short runs without symptoms in the legs or feet.

What can be done to reduce the chances of developing exercise-induced compartment syndrome?
Exercise-induced compartment syndrome is usually an overuse injury and as such a proper training program is key to helping your body adapt to the training load. Too much, too fast, too frequent, and too often are the most common risk factors. However, there are cases in which the anatomical structure of the muscle compartments leads to symptoms. In these cases, it is thought genetics plays a role. Since your genetics cannot be altered, optimizing your biomechanics and training become the primary preventive strategies that work. This involves consistent focus on strength and flexibility of the hips, legs, ankles, and feet. Finally, there is evidence that some running form changes and shoe changes can reduce the load in the tibia that causes the the compartment syndrome. Monitor and modulate your training to avoid the “too much” rules mentioned above and you’re less likely to develop symptoms.

This information is not intended to diagnose, treat, or prevent any injury or disease. It is intended to serve as an overview of running-related injuries and should not be used as a substitute for sound medical advice from a doctor or therapist.