title: Precision of recumbent crown-heel length when using an infantometer.
abstract: Crown-heel length (CHL) measurement is influenced by technique, training, experience and subject cooperation. We investigated whether extending one or both of an infant's legs affects the precision of CHL taken using an infantometer. The influence of staff training and infant cooperation were also examined.
  
  
  
  CHL was measured in children (aged 2), infants (aged 1) and newborns, by extending one or both legs. The subject's level of cooperation was recorded. Mean differences were compared using Student's t-test; intra- and inter-observer variability were assessed using Bland-Altman plots with 95 % limits of agreement. Intra- and inter-observer technical errors of measurement (TEMs) were also calculated.
  
  
  
  Measuring CHL in newborns using only one leg resulted in significantly longer measurements. Across all groups, there was less inter-observer variability using both legs; 95 % limits of agreement were lower and TEMs smaller. Larger measurement differences were seen if children were uncooperative.
  
  
  
  This study supports measuring CHL with both legs extended. The two-leg technique reduces variability and increases precision by allowing the measurer to control better the position and movements of the infant's body.
authors.affiliation: Nuffield Department of Obstetrics & Gynaecology, and Oxford Maternal & Perinatal Health Institute, Green Templeton College, University of Oxford, Women's Centre, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK. leila.cheikhismail@obs-gyn.ox.ac.uk.
authors.forename: Leila
authors.initials: L
authors.lastname: Cheikh Ismail
authors.affiliation: Nuffield Department of Obstetrics & Gynaecology, and Oxford Maternal & Perinatal Health Institute, Green Templeton College, University of Oxford, Women's Centre, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK.
authors.forename: Fabien A
authors.initials: FA
authors.lastname: Puglia
authors.affiliation: Centre for Statistics in Medicine, Botnar Research Centre, University of Oxford, Windmill road, Oxford, OX3 7LD, UK.|Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, The Peter Medawar Building, University of Oxford, South Parks Road, Oxford, OX1 3SY, UK.
authors.forename: Eric O
authors.initials: EO
authors.lastname: Ohuma
authors.affiliation: Ludwig Institute for Cancer Research Ltd, University of Oxford, Nuffield Department of Medicine, Old Road Campus Research Building, Oxford, OX3 7DQ, UK.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Ash
authors.affiliation: Nuffield Department of Obstetrics & Gynaecology, and Oxford Maternal & Perinatal Health Institute, Green Templeton College, University of Oxford, Women's Centre, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK.
authors.forename: Deborah C
authors.initials: DC
authors.lastname: Bishop
authors.affiliation: Nuffield Department of Obstetrics & Gynaecology, and Oxford Maternal & Perinatal Health Institute, Green Templeton College, University of Oxford, Women's Centre, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK.
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Carew
authors.affiliation: Nutrition and Health Department, College of Food and Agriculture, United Arab Emirates University, Al-Ain, United Arab Emirates.
authors.forename: Ayesha Salem
authors.initials: AS
authors.lastname: Al Dhaheri
authors.affiliation: Departments of Community Health and Pediatrics, Lifespan Health Research Center, Boonshoft School of Medicine, Dayton, OH, USA.
authors.forename: Wm Cameron
authors.initials: WC
authors.lastname: Chumlea
mesh_terms: D000886:Anthropometry / Q000295:instrumentation* / Q000379:methods; D001827:Body Height; D002675:Child, Preschool; D002983:Clinical Competence; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results
keywords: Anthropometry; Growth; Pre-school children