Development of stratified normative data and reference equations for the timed up and down stairs test for healthy children 6–14 years of age

Abstract

Objectives: To generate normative data on healthy children aged 6-14 years for the timed up and down stairs (TUDS) test, and to provide reference equations. Design and setting: Cross-sectional study at two primary schools. Participants: Healthy children 6-14 years of age. Main outcomes measures: Anthropometric data and Minnesota Leisure-Time Physical Activity Questionnaire from children were collected before the start of the TUDS test. Heart rate, blood pressure and perceived exertion were measured at the beginning and at the end of the test. Two trials of the TUDS test were performed with 15-minute of rest on the same day and the better of the two trials was used in the analyses. The reference equations were established using the anthropometric variables as possible predictors of the TUDS test. Results: Two hundred fifty eight children (125 boys and 133 girls) were assessed. The mean TUDS test score decreased significantly from 6 to 14 years of age in boys and girls alike, with statistically significant differences between the three age range groups. A significant difference was found between girls and boys in TUDS test score. The 56% of the variation in TUDS test score could be explained by age, height, and weight in boys [TUDSsec score=(9.967-(0.182×Ageyears)+(0.025×Weightkg)-(2.546×Heightm)], while 50% could be explained in girls [TUDSsec score=10.553-(0.194×Ageyears)+(0.019×Weightkg)-(2.406×Heightm)]. The inclusion of physical level activity increased the variability explained (boys: 59%; girls: 51%). Conclusions: TUDS score improved as the age of the children increased, with boys achieving better values than girls within each age group. TUDS test score can be easily predicted from age, height, and weight. The inclusion of the child's physical activity level increased the variance explained by the equation.