Acute compartment syndrome has multiple causes: fractures, crush injury, vascular trauma and burns. Exertional compartment syndrome may be acute (progressive) or chronic (usually reversible). The acute form usually occurs after intensive exercise. Closed muscle rupture is an uncommon cause with few reports. We report two cases, in the peroneal compartment of the leg and the flexor compartment of the forearm, to show that a high index of suspicion, allowing prompt diagnosis and fasciotomy, will enable a full recovery without complications.