Valley sign in duchenne muscular dystrophy: importance in patients with inconspicuous calves.

Several patients of Duchenne muscular dystrophy (DMD) do not demonstrate clinically remarkable calf hypertrophy. A new clinical sign visible behind the shoulders, which may be called 'valley sign', was tested for its utility in such cases as clinical diagnosis becomes difficult in these patients. Out of 142 DMD patients seen in the last 7 years, 12 were found to have inconspicuous calves. All the 12 patients had clinical, biochemical and/or genetic evidence of DMD. The new sign was examined by 3 independent observers in these 12 DMD patients and in 10 patients with other neuromuscular diseases. Eight DMD patients and none of the others showed positive sign. This signifies importance of this sign in the clinical diagnosis of DMD in those children in whom the calf muscle bulk is apparently normal.