Abstract
Motor coordination deficit is a cardinal feature of autism spectrum disorder (ASD). Theevaluation of coordination of children with ASD is either lengthy, subjective (via observationalanalysis), or requires cumbersome post analysis. We therefore aimed to use tri-axial accelerometersto compare inter-limb coordination measures between typically developed (TD) children and childrenASD, while jumping with and without a rhythmic signal. Children aged 5-6 years were recruited tothe ASD group (n = 9) and the TD group (n = 19). Four sensors were strapped to their ankles and wristand they performed at least eight consecutive jumping jacks twice: at a self-selected rhythm and witha metronome. The primary outcome measures were the timing lag (TL), the timing difference of themaximal acceleration of the left and right limbs, and the lag variability (LV), the variation of TL acrossthe 5 jumps. The LV of the legs of children with ASD was higher compared to the LV of the legs of TDchildren during self-selected rhythm jumping (p < 0.01). Additionally, the LV of the arms of childrenwith ASD, jumping with the rhythmic signal, was higher compared to that of the TD children (p <0.05). There were no between-group differences in the TL parameter. Our preliminary findingssuggest that the simple protocol presented in this study might allow an objective and accuratequantification of the intra-subject variability of children with ASD via actigraphy.