title: Do fitness and fatigue affect gait biomechanics in overweight and obese children?
abstract: The purpose of this study was to determine how an overweight or obese child's cardiorespiratory fitness level and a state of fatigue affect gait biomechanics.
  
  
  
  Using a three-dimensional motion analysis system, twenty-nine (female and male) overweight and obese children aged 8-11 years walked on force plates before and after being fatigued from the Progressive Aerobic Cardiovascular Endurance Run (PACER) protocol. Joint moments were calculated for the knee and hip in the frontal and sagittal planes.
  
  
  
  In a non-fatigued state, peak hip and knee adductor moments showed a negative relationship with cardiorespiratory fitness level (R2=0.26, 0.26). After the subjects were fatigued, peak hip extensor (p=0.02), peak knee extensor moments (p=0.02) and peak knee adductor moments (p=0.01) showed a significant increase.
  
  
  
  This trend illustrates that as an overweight or obese individual's fitness improves, the lower limb joint moments in the frontal plane decrease when walking. However, with the introduction of cardiorespiratory fatigue, lower limb joint moments tend to increase in the frontal and sagittal planes. Increased joint stress may have potential implications for obese children performing physical activity, as well as for clinicians who are attempting to intervene in the cycle of obesity.
authors.affiliation: Department of Physical Therapy, California State University, Fresno, United States. Electronic address: bhsingh@csufresno.edu.
authors.forename: Bhupinder
authors.initials: B
authors.lastname: Singh
authors.affiliation: Department of Physical Therapy, California State University, Fresno, United States.
authors.forename: Megan G
authors.initials: MG
authors.lastname: Negatu
authors.affiliation: Department of Health and Human Physiology, University of Iowa, United States.
authors.forename: Shelby L
authors.initials: SL
authors.lastname: Francis
authors.affiliation: Department of Health and Human Physiology, University of Iowa, United States.
authors.forename: Kathleen F
authors.initials: KF
authors.lastname: Janz
authors.affiliation: Department of Physical Therapy and Rehabilitation Sciences, University of Iowa, United States.
authors.forename: H John
authors.initials: HJ
authors.lastname: Yack
mesh_terms: D001696:Biomechanical Phenomena; D002648:Child; D005221:Fatigue / Q000503:physiopathology*; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint; D035002:Lower Extremity; D008297:Male; D009765:Obesity / Q000503:physiopathology*; D050177:Overweight / Q000503:physiopathology; D010809:Physical Fitness; D016138:Walking
keywords: Children; Fatigue; Fitness; Gait; Kinetics; Obesity