A painful condition caused by increased pressure within a muscle compartment. An acute compartment syndrome is indicated by an intramuscular compartment pressure above 40 mmHg at rest (normally, it is 0–10 mmHg). It can arise as a result of a direct impact or muscle rupture. If an acute compartment syndrome is not relieved immediately by rest, surgical decompression may be necessary to relieve the pressure against blood vessels, otherwise the blood supply to tissues will be compromised and the tissue may die. Acute compartment syndromes are rare; most cases are associated with fractures or dislocations of the leg, but a few are caused by prolonged increase in exercise intensity (e.g. overambitious marathon training by a novice runner). A chronic compartment syndrome arises as a result of overtraining and is characterized by intermittent excessive pressure. During activity, the muscles within the compartment swell, and press nerves and blood vessels against the wall of the compartment. Pain associated with ischaemia is localized to the muscles. Although the pain is relieved by rest, every time the athlete resumes activity the pain starts again. Although many sports people alter their activity patterns until the symptoms settle, usually, the only long-term solution is surgical decompression. The most commonly affected compartment is the anterior tibial compartment of the lower leg (see anterior compartment syndrome). See also shin splints.
Subjects: Sports and Exercise Medicine.