Gait deviations in Duchenne muscular dystrophy—Part 1. A systematic review

Background: Although prolonged ambulation is considered important in children with Duchenne muscular dystrophy (DMD), articles describing gait deviations in DMD are scarce. Research question: Therefore, our research questions were the following: 1) what are the most consistently reported spatiotemporal-, kinematic-, kinetic-, and muscle activity deviations in children with DMD in literature, 2) what is the quality of the studies describing these deviations, and 3) is there need for further research? Methods: We conducted a systematic literature search for studies published before the end of June 2017 in six online databases. We created a data extraction form to define information on materials and methods and on the analyzed gait parameters for each paper included in the review. If enough information was available, we calculated standardized mean differences (SMDs). Results: The search yielded nine articles, but generalizability was poor. Seventy-nine parameters were analyzed by seven research groups, but they only agreed on a decrease in walking speed (minimal SMD: 1.26), stride length (1.83), step length (1.80), dorsiflexion during swing (1.43), maximal power generation at the hip (0.92), maximal knee extension torque (0.99), maximal dorsiflexion torque (−1.30), and maximal power generation at the ankle (0.92), and an increased knee range of motion (−0.82) in DMD. Significance: In order to keep children with DMD ambulant as long as possible, a clear understanding of their pathological gait pattern is necessary. However, gait deviations in DMD appear not well defined. Previous studies appear to be of an exploratory nature while using predefined gait parameters to assess an undirected null hypothesis. This made them prone to regional focus bias, thereby increasing the chance of a type I error. Therefore, further research is required to define the altered gait pattern in children with DMD.