Compartment syndrome of the lower extremities is defined within four and sometimes five fascial compartments of the lower leg. The classic four compartments are the anterior, lateral, superficial posterior, and deep posterior. The fifth compartment is sometimes considered alone comprised solely of the tibialis posterior. These compartments are defined by the fascial planes that encompass them and all have their own sensory/motor nerves and muscles groups that occupy the compartment. The anterior/lateral compartments are more often affected.
Reference : Foot and Ankle Sports Medicine. Lippincott Williams and Wilkins, 2013.