The Effects of Obesity on Gait Variability in Children
Purpose: Childhood obesity has more than doubled in children and tripled in adolescents in the past 30 years. Prior studies have evaluated the effect of BMI on a child's gait. Recent efforts have turned towards the examination of degree and pattern of variation within gait in the elderly to identify those at risk for falling. Applying this methodology to pediatric gait is novel. The purpose of this cross-sectional study is to collect temporal-spatial gait data (TSP) from children of different weight groups completing a self-selected and fast paced walk to assess variation across tasks. It is hypothesized that speed-differentiated walking tasks produce a different response among the weight groups.
Methods : Gait testing was performed using the GAITRite (CIR Systems, Inc., Havertown, PA). Participants completed two trials each of self-selected and fast paced walks. Sensors in the walkway interfaced with custom software to measure means and standard deviations of gait variables (TSP) for each step in the walk. Primary measures included variations in stance time and swing time. Coefficient of variation (CV) was calculated to relate degree of variation to the mean. CDC guidelines were used to determine BMI percentile-for-age. Data was normalized for age and analyzed across speed-differentiated walking tasks using SPSS software.
Results : One hundred eighty-eight participants, ages 5-12, underwent gait testing (120 normal weight; 34 over-weight; 34 obese). Within each weight group, there was a statistically significant difference in variation (CV) over the speed-differentiated tasks, indicating a difference in self-selected versus fast paced walks regardless of weight. In comparing weight groups, the normal weight and overweight groups displayed increased variation (CV) from self-selected to fast paced walks, and the overweight group expressed a statistically significant increase in variation across tasks compared to the normal weight group. The obese group expressed a statistically significant different response to the overweight group, but not the normal weight group.
Conclusions : Significant increase in variation (CV) across speed-differentiated walks in the overweight group suggests a poorer response to activity compared to their age-matched normal weight peers. Future studies are needed to determine the implications of these findings in a pediatric population. The lack of significant difference between the obese and normal weight groups in response to speed-differentiated walks represents possible adaptive strategies. This is also an area for future study.
Significance: Parents and physicians should be aware of an overweight child's compromised gait variability, as well as the differences in activity response across weight groups.