Duchenne's muscular dystrophy (DMD) is a common X-linked neuromuscular disease which predominantly affects skeletal and cardiac muscle. The absence of dystrophin, the metabolic defect that causes DMD, leads to a peculiar cardiomyopathy which initially affects the posterior wall of the left ventricle. We review evidence that dystrophin deficient myocytes become dystrophic in order of increasing axial stress upon the myocyte. Thus, dystrophin's function may be that of physically reinforcing the sarcolemma against the axial forces exerted upon the myocyte.