Symmetry of foot alignment and ankle flexibility in paediatric Charcot–Marie–Tooth disease

BackgroundCharcot–Marie–Tooth disease is the most common inherited nerve disorder and typically presents with pes cavus foot deformity and ankle equinus during childhood. Level in the variation of symmetry of musculoskeletal lower limb involvement across the clinical population is unknown, despite early reports describing gross asymmetry.MethodsWe measured foot alignment and ankle flexibility of the left and right limbs using accurate and reliable standardised paediatric outcome measures in 172 patients aged 3–20 years with a variety of disease subtypes recruited from the United States, United Kingdom, Italy and Australia.FindingsWhile a large range of differences existed between left and right feet for a small proportion of children, there was no overall significant difference between limbs.InterpretationThere are two important implications of these findings. Children with Charcot–Marie–Tooth disease generally exhibit symmetrical foot alignment and ankle flexibility between limbs. As such, analysing one limb only for biomechanical-related research is appropriate and satisfies the independence requirements for statistical analysis. However, because there are large differences between feet for a small proportion of children, an individualised limb-focused approach to clinical care is required.