Ankle contractures and functional motor decline in Duchenne muscular dystrophy

Abstract

IntroductionThis prospective, correlational pilot study investigated the relationship between ankle plantar flexion contractures and motor function in boys with Duchenne muscular dystrophy in British Columbia (BC), Canada. ParticipantsAmbulatory boys with Duchenne muscular dystrophy were recruited from BC Children’s Hospital, which follows everyone with Duchenne muscular dystrophy in BC ≤ 18 years of age (n = 14). MethodsSpearman and Pearson correlation coefficients were estimated to examine the association between the degree of ankle dorsiflexion range of motion and North Star Ambulatory Assessment scores and the degree of ankle dorsiflexion range and six-minute walk test distances. ResultsOur analysis showed a moderate correlation between the degree of ankle dorsiflexion range and North Star Ambulatory Assessment scores [rho (14) = 0.50; p = 0.070] and a weak correlation between ankle dorsiflexion range of motion and six-minute walk test distances [rho (13) = 0.08; p = 0.747], however neither result was statistically significant. DiscussionAlthough a significant relationship between ankle dorsiflexion range of motion and motor function was not found, the variability of ankle dorsiflexion range suggests challenges with preventing ankle contracture. This reinforces the importance of assessing ankle range of motion in boys with Duchenne muscular dystrophy with sufficient frequency to identify a need for additional interventions.