title: Metabolic cost, mechanical work, and efficiency during normal walking in obese and normal-weight children.
abstract: OBJECTIVE
  This study aimed to investigate the influence of childhood obesity on energetic cost during normal walking and to determine if obese children choose a walking strategy optimizing their gait pattern.
  
  
  METHODS
  Sixteen obese children with no functional abnormalities were matched by age and gender with 16 normal-weight children. All participants were asked to walk along a nearly circular track 30 m in length at a self-selected speed. Spatiotemporal data, kinematics, and ground reaction force were collected during walking using a three-dimensional motion analysis system. Metabolic cost was collected by a portable gas analyzer simultaneously.
  
  
  RESULTS
  The mechanical energy expenditure (MEE) was 72.7% higher in obese children than in normal-weight children. The net metabolic cost was 65.7% higher in obese children. No difference was found in the metabolic rate (J x kg(-1) x m(-1)), normalized MEE (J x kg(-1) x m(-1)) and mechanical efficiency between the obese and normal-weight groups. The obese children walked with a 0.15 m/s slower walking speed, 10.0% shorter cadence, and 30.9% longer double-support phase compared with normal-weight children. In addition, no differences were found in the mediolateral and vertical body center of mass displacement.
  
  
  CONCLUSIONS
  Body mass played a dominant role in the total metabolic and mechanical cost per stride. Obese children may adopt a walking strategy to avoid an increase in the metabolic cost and the mechanical work required to move their excess body mass.
authors: The University of Auckland.
authors: Liang
authors: L
authors: Huang
authors: School of Kinesiology, Shanghai University of Sport, 650 Qingyuanhuan Road, Shanghai 200438, China.
authors: Peijie
authors: P
authors: Chen
authors: School of Kinesiology, Shanghai University of Sport, 650 Qingyuanhuan Road, Shanghai 200438, China.
authors: Jie
authors: J
authors: Zhuang
authors: The University of Auckland.
authors: Sharon
authors: S
authors: Walt
mesh_terms: D001481:Basal Metabolism / Q000502:physiology; D002153:Calorimetry, Indirect; D002648:Child; D004734:Energy Metabolism / Q000502:physiology*; D005684:Gait / Q000502:physiology; D006801:Humans; D009765:Obesity / Q000503:physiopathology*; D010101:Oxygen Consumption / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology; D016138:Walking / Q000502:physiology*