title: A comparison of hydrostatic weighing and air displacement plethysmography in adults with spinal cord injury.
abstract: OBJECTIVE
  To compare (1) total body volume (V(b)) and density (D(b)) measurements obtained by hydrostatic weighing (HW) and air displacement plethysmography (ADP) in adults with spinal cord injury (SCI); (2) measured and predicted thoracic gas volume (V(TG)); and (3) differences in percentage of fat measurements using ADP-obtained D(b) and HW-obtained D(b) measures that were interchanged in a 4-compartment body composition model (4-comp %fat).
  
  
  METHODS
  Twenty adults with SCI underwent ADP and V(TG), and HW testing. In a subgroup (n=13) of subjects, 4-comp %fat procedures were computed.
  
  
  METHODS
  Research laboratories in a university setting.
  
  
  METHODS
  Twenty adults with SCI below the T3 vertebrae and motor complete paraplegia.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Statistical analyses, including determination of group mean differences, shared variance, total error, and 95% confidence intervals.
  
  
  RESULTS
  The 2 methods yielded small yet significantly different V(b) and D(b). The groups' mean V(TG) did not differ significantly, but the large relative differences indicated an unacceptable amount of individual error. When the 4-comp %fat measurements were compared, there was a trend toward significant differences (P=.08).
  
  
  CONCLUSIONS
  ADP is a valid alternative method of determining the V(b) and D(b) in adults with SCI; however, the predicted V(TG) should be used with caution.
authors.affiliation: Department of Kinesiology and Health Promotion, Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40506-0219, USA. jlclas0@pop.uky.edu
authors.forename: Jody L
authors.initials: JL
authors.lastname: Clasey
authors.forename: David R
authors.initials: DR
authors.lastname: Gater
mesh_terms: D000293:Adolescent; D000328:Adult; D000886:Anthropometry / Q000379:methods*; D001823:Body Composition; D049628:Body Size; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D010991:Plethysmography; D015203:Reproducibility of Results; D013119:Spinal Cord Injuries; D013904:Thoracic Vertebrae