Abnormally increased intramuscular pressure in human legs: comparison of two experimental models

Abnormally increased pressure in the anterior compartment of 20 legs in 10 subjects was induced by applying venous stasis of a casted leg and external compression by a cylindrical air splint of the contralateral leg. The effects of increased intramuscular pressure (IMP) on blood perfusion pressure and clinical symptoms in the foot were compared during 30 minutes by the two methods.

Intramuscular pressure increased to 38.9 (SD = 2.9) mm Hg when venous stasis was applied and to 39.8 (SD = 1.6) by external compression (not significant). Blood perfusion pressure in the anterior compartment decreased significantly to 25 mm Hg in both legs when they were elevated. Subjects experienced loss of sensation and muscular weakness only in the foot of the casted obstructed leg.

Venous stasis of a casted elevated leg is an alternative experimental model to induce abnormally increased intramuscular pressure and neuromuscular dysfunction in the human leg. The venous stasis model may be better than external compression in the study of pathogenesis and pathophysiology of simulated imminent acute compartment syndrome in man.