1. Three cases are reported of ischaemic necrosis of the anterior tibial muscles which were not due to injury. In two, ischaemia was the result of strenuous or unaccustomed exercise in young adults; in the third it was an incident in a systemic disturbance. All three cases were probably the result of spasm of a large segment of the anterior tibial artery. 2. The clinical features during the first few hours resemble those of tenosynovitis of the tibialis anterior; and after twelve to twenty-four hours those of cellulitis of the leg. Later there is "drop foot" due to muscle weakness, contracture limiting plantar-flexion movement, and woody hardness of the muscles in the middle third. 3. The morbid histology is similar to that of Volkmann's ischaemic contracture. 4. The possible explanationsâprimary arterial disease, arterial occlusion by pressure of the interosseous membrane, occlusion by tension within the fascial space, intraluminary occlusion by embolism or thrombosis, and fatigue arterial spasm, are discussed. 5. The vascular pattern of the anterior tibial muscles has been studied by experimental injections in cadavers. 6. It is concluded that the most likely cause is spasm of the anterior tibial artery due to muscle fatigue, aggravated by increased tension within the anterior fascial compartment due to reaction after strenuous exercise. 7. Treatment is outlined. Exploration of the anterior tibial artery within the first twelve hours is warranted, but late exploration may be dangerous. 8. Although not previously recognised, evidence is shown that regeneration of necrotic muscle is possible in the human being.
