Novel SLH data was collected from children to describe and compare performance, temporal, and postural outcomes between different FASD subgroups i.e. Foetal Alcohol Syndrome (FAS), Partial FAS (PFAS), Alcohol-related Neurodevelopmental Disorder (ARND) and typically developed (TD) peers.
An observational cross-sectional study, involving 9–10-year-old schoolchildren was conducted in rural South Africa. Participants were eligible if diagnosed with FASD or no prenatal alcohol exposure (TD group) and parental consent and child assent were obtained. Participants were mounted with inertial motion capture sensors before performing a standardised task: four consecutive overground hops followed by a unilateral landing onto an instrumented pressure platform. In addition to the traditional task duration measure, detailed temporal and lower-limb joint angle analysis were performed for several task subphases. Sway area was also calculated during landing. Descriptive statistics and linear regression analysis were performed to describe and identify significant differences between the TD and FASD subgroups adjusting for age, sex, height, and weight. Ethical approval was granted by Stellenbosch University (N15/09/086).
No significant differences in task duration between TD participants and FASD subgroups were found for either leg. Participants with FAS were slower than TD participants during the hopping phase for both legs. Time to stabilisation was lower for TD participants than the FASD subgroups on the dominant leg, but higher on the non-dominant leg. On the non-dominant leg, the participants with FAS spent significantly more time in foot contact (p=0.26) and less time in flight (p=0.048) in the first three hops compared to TD participants. For dominant-leg trials, the participants with ARND showed a significant increase in flight time (p=0.037) on the final hop compared to the TD participants. On the dominant leg, clinically and statistically significant differences were observed relative to the TD participants in ankle dorsiflexion at initial contact (FAS/PFAS reduced by 6°; p=0.019, p=0.004) and range during contact (PFAS increased by 5°; p=0.001) during the final hop. For the non-dominant leg during the final hop, the children with FAS displayed significantly less knee range compared to the TD group (1-2°; p=0.047). No significant differences in sway area were observed between TD and FASD groups, although the children with FAS exhibited greater sway variability.
Children diagnosed with FAS were generally slower to complete SLH and took longer to reach stability. Postural differences were noticeable on the dominant ankle with increased dorsiflexion during initial contact but using less dorsiflexion range but only during the final hop before landing.
During SLH, motor deficits manifest differently within FASD subgroups and compared to TD children. Identifying these differences may contribute towards better and more targeted clinical care.
single leg hopping
motor
