Compartment Syndrome

The calf is divided into four sections, known as compartments. Each compartment contains muscles, blood vessels, and nerves. These are in turn surrounded by a thick, nearly inflexible structure called the muscle fascia.

During exercise, blood flows to the muscles, causing the contents of a compartment to expand. If the pressure becomes too high relative to the available space, it can result in the muscles not receiving enough oxygen. Some people find this painful, others do not—and we don’t fully understand why.

Non-acute

It is important to emphasize that in this article we are not discussing acute compartment syndrome. This is considered a serious medical emergency and typically occurs immediately after an acute injury. It most often occurs after a fracture, but it can also result from a strong impact on the muscle. Non-acute compartment syndrome, on the other hand, develops gradually over time.

The condition is common among athletes who participate in running and jumping sports, such as track and field, handball, and football. Men and women under 30 are most commonly affected.

Risk Factors

There are certain factors that can increase your likelihood of developing this condition. One theory is that repetitive or one-sided exercise may be a triggering factor. This is especially true if you engage in activities where the calf acts as a shock absorber against the ground without getting adequate rest. These factors often have little impact on their own, until the training load suddenly exceeds what the body can handle.

Symptoms and signs

The pain is often cramp-like. As the problem persists over time, you can often predict when it will occur. If you frequently run a set route, the pain may occur at a specific time or a specific spot on the course. It is common for the pain to gradually worsen during the session but to disappear once you stop exercising. The longer the problem persists, the longer it takes for the pain to subside.

The pain often occurs in different parts of the calf, depending on which compartment is affected. The muscles feel tight and sore. If the pressure becomes very intense, nerves may also temporarily lose their blood supply. This can cause a tingling or prickling sensation or numbness, and in some cases, muscle weakness.

Diagnosis

A doctor or physical therapist will conduct a thorough examination. The symptoms (listed above) will be key to making the diagnosis. Since compartment syndrome is a relatively rare condition, the first step is often to rule out other conditions, such as medial tibial stress syndrome (shin splints) and stress fractures. There are also calf conditions, such as those seen in speed skaters, that resemble compartment syndrome but do not fall under this diagnosis.

It is unusual to experience pain when not exercising. The examination is therefore often performed after a run or pain-provoking exercise. To diagnose the condition, it is sometimes necessary to measure the pressure in a compartment. This reveals that the pressure is higher than what is considered normal.

Treatment

In the early stages, rest and stretching of the calf muscles are recommended, along with a short period of rest. These measures can alleviate symptoms but have little effect beyond that. The most important step is to identify the underlying cause of the problem. This may involve identifying risk factors and determining whether they can be modified.

The athlete should avoid activities that trigger symptoms for up to 3 months and then gradually resume training. The challenge is figuring out how to do this. For some, it means better warm-up; for others, changing the surface they run on is effective. It may be a good idea to consult a physical therapist, who can provide guidance. Before surgery is considered, you should have tried one or two rounds of non-surgical treatment.

Maintain your fitness

Good physical fitness can be maintained by engaging in other, pain-free exercises. This could include swimming and cycling or other forms of exercise you enjoy.