Background, Motivation and Objective Duchenne muscular dystrophy (DMD) is a lethal genetic disorder primarily occurring in males, which causes progressive muscle degeneration through necrosis and replacement of muscle fibers with fat and fibrosis. Current metrics for measurement of disease state, such as physical testing, are insufficient for properly tracking the progression of the disease. The aim of this work is to develop an improved metric for monitoring disease state with Viscoelastic Response (VisR) ultrasound. VisR ultrasound is an acoustic radiation force (ARF)-based imaging method that delineates tissue viscoelasticity by fitting displacements induced by successive, co-located ARF impulses to a mechanical model.