Chronic Exertional Compartment Syndrome

Chronic exertion compartment syndrome, more recently known as anterior biomechanical overload syndrome (ABOS), is pain that develops at the anterior part of the lower leg during exercise. Symptoms then usually settle when their aggravating activity stops.

There are four compartments in the lower leg which include the anterior, lateral, superficial posterior and deep posterior compartments. Each compartment contains is designed to separate each muscle group, and within each compartment there are various arteries, veins and nerves. During repetitive and strenuous exercise, there can be a 20% increase in muscle volume due to increased blood flow. This can lead to increased pressure within the anterior compartment which leads to compression of the small vessels leading to reduced blood flow and pain.

While chronic exertional compartment syndrome is considered a rare cause of lower limb pain, incidence rates in active patients can be as much as 33%.

People who experience chronic exertional compartment syndrome usually report:

• Pain which starts within the first 30 minutes of exercise which can radiate to the foot and ankle

• Reduced range of movement

• Feeling of tightness

• Possible swelling / increased muscle tone

• Pain

• Paraesthesia

Following a thorough history, a physical examination will usually identify:

• Daily activities usually not provocative

• Altered biomechanics (such as increased dorsiflexion during running)

• Increased tone in the affected muscle (usually tibialis anterior)

• Reduced range of movement

• Reduced strength

• Tenderness over the affected muscle

Once an accurate diagnosis has been made, various interventions that can help with symptoms include:

• Advice and education

• Activity modification

• Gait analysis and retraining (such as running)

• Home exercise programme which includes stretching and strengthening

• Soft tissue massage