Two-Year Longitudinal changes in lower limb strength and its relation to loss in function in a large cohort of patients with Duchenne Muscular Dystrophy

OBJECTIVEThe main objective of this study were to examine the effect of disease on strength in two functionally important lower limb muscles over a period of two-years in children with Duchene Muscular Dystrophy (DMD). DESIGNSeventy-Seven DMD children participated in this study. Plantar flexors (PF), knee extensors (KE) strength and performance on timed tests (Six-min walk, 4-stairs, 10m-walk, supine-up) was assessed yearly over two-years. Multivariate normal regression was used to assess changes in strength over time in the DMD group. Spearman correlations were computed to examine relationship between strength and function. RESULTSNormalized PF and KE strength, showed a significant decrease (p