title: Six-minute walk test in healthy children: is the leg length important?
abstract: BACKGROUND
  Measures as height, age, and weight influence the six-minute walk test (6MWT). It was shown that children's true leg length (TLL) influence the 6MWT distance but so far it has never been evaluated how much this variable could predict the distance walked related to height. Our hypothesis is that there should not have any significant difference between models including height or TLL.
  
  
  OBJECTIVE
  To establish and to compare the predicted walked distance of healthy children in the 6MWT by two distinct models, one including TLL and other including height.
  
  
  METHODS
  Observational cross sectional study. A total of 161 healthy children (84 girls, 52.2%), 6-13 years old from three local primary and secondary schools. Two 6MWT were performed following ATS guidelines. Weight, height, and TLL were measured. The longer walked distance was selected for statistical analysis.
  
  
  RESULTS
  Anthropometric data were similar for both genders into each group of age. Mean (±SD) walked distances in whole group were: boys 704.4 m (77.7); girls 681.6 m (67.9; P = 0.049). In the univariate regression to predict the distance walked, the adjusted coefficients to TLL and height were in boys: 0.46 and 0.39; and in girls: 0.35 and 0.29, respectively. After adjusting for age and weight, the residuals of the two equations were not significantly different (P = 0.998).
  
  
  CONCLUSIONS
  The model including TLL to predict the walked distance by healthy children explained more of the variation on the walked distance in the 6MWT than the model using the height but without significant difference between the models.
authors.affiliation: Pulmonary Rehabilitation Center, Federal University of São Paulo/Associação de Assistência à Criança Deficiente, São Paulo, Brazil.
authors.forename: Andréia C
authors.initials: AC
authors.lastname: Oliveira
authors.forename: Camila C
authors.initials: CC
authors.lastname: Rodrigues
authors.forename: Denise S
authors.initials: DS
authors.lastname: Rolim
authors.forename: Altay A L
authors.initials: AA
authors.lastname: Souza
authors.forename: Oliver A
authors.initials: OA
authors.lastname: Nascimento
authors.forename: José R
authors.initials: JR
authors.lastname: Jardim
authors.forename: Tatiana
authors.initials: T
authors.lastname: Rozov
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000704:Analysis of Variance; D001827:Body Height / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D001837:Body Weights and Measures / Q000379:methods / Q000706:statistics & numerical data*; D002648:Child; D003430:Cross-Sectional Studies; D005080:Exercise Test / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007866:Leg; D008297:Male; D017678:Sex Distribution; D016138:Walking / Q000706:statistics & numerical data*