Natural history of ankle function during gait in youth with Charcot-Marie-Tooth disease types 1 and 2

•In CMT1 peak dorsiflexion in terminal stance (TST) increased through age 13.•In CMT1 peak dorsiflexion in TST plateaued in the normal range after 13.•In CMT1 peak ankle angle in mid-swing was closely related to the angle in TST.•In CMT2 there was no significant association of ankle function with age.•Heterogeneity in gait highlights the need to understand patient-specific gait changes.