Reproducibility of energy cost of locomotion in ambulatory children with spina bifida

Abstract

Objectives Many ambulatory children with Spina Bifida (SB) experience functional decline in ambulation despite stable or even improving motor exams. Improving or maintaining low energy cost of locomotion during childhood and throughout the teenage years, could be an important goal for children and adolescents with SB. Purpose of this study was to determine reproducibility of energy expenditure measures during gait in ambulatory children with SB. Design Reproducibility study. Setting Child Development and Exercise Center of the University Children's Hospital in Utrecht, the Netherlands. Participants Fourteen ambulatory children (6 boys/8 girls) with SB. Mean age was 10.8 years (±3.4). Interventions Net and gross energy expenditure measures during locomotion were determined during a six-minute walking test. These measures consisted of energy consumption (ECS), expressed in J/kg/min, and energy cost (EC), expressed in J/kg/m. For reliability, the intra-class coefficient (ICC) was determined. For agreement, the smallest detectable difference (SDD) was calculated. Results ICCs vary from 0.86 to 0.96 for both EC and ECS. The SDD ranges from 18–24% for gross measures, up to over 30% for net values. Conclusion Reproducibility of energy expenditure during ambulation in children with SB should be considered carefully when using these measures in the evaluation of gait. High reliability of energy expenditure measurements makes these measurements appropriate to use as discriminative tools in children with SB, while agreement of only gross EC seems acceptable to use as a evaluative tool in children with SB. Overall, measures of reliability and agreement seem higher in young children when compared to adolescents. Further research is recommended to determine clinically relevant changes in energy expenditure in children with SB.