Walking and maintaining balance are essential for participating in daily life. For children with achondroplasia, reaching these milestones is with a delay and during growth, challenges persist for those skills. However, the impact of developmental changes on gait and balance in this population has not yet been investigated longitudinally. Therefore, this study aimed to examine the influence of growth on gait pattern and postural control in children with achondroplasia over a two-year period. 6 children with achondroplasia (whereas 5 are treated with vosoritide, a growth promoting peptide) and 24 children of average height participated in a 3D gait analysis and static bipedal posturographic (eyes open/closed and foam pad with eyes open/closed) measurements every six months. Using Nonparametric Analysis of Longitudinal Data and the smallest real differences, changes over time and between the cohorts were investigated. Results showed that the growth development between the cohorts were similar. Still, the key characteristics of achondroplasia were prominent and revealed significant differences for the anthropometric parameters. Spatio- temporal, kinematic parameters revealed additional significant differences for known characteristics like gait velocity, step- and stride length, cadence, step & stride time, stance- and swing phase and single support time, between the cohorts. Finally, posturographic parameters present significant differences in the foam pad eyes closed condition between the cohorts. Overall, all children show considerable variability for gait and posturographic parameters, with greater variability present children with achondroplasia. The findings of this work indicate that there are no general differences in the growth curves between children with achondroplasia and children of average height. However, the different baseline of both cohorts, with the vosoritide treatment and the already changed gait pattern of achondroplasia must be considered as additional factors. Further research is needed to investigate broader age groups, possible gender differences and greater sample sizes, e.g. through a multi-center study.
Hergenröther et al. (Thu,) studied this question.