title: Validity in measuring breathing movements with the Respiratory Movement Measuring Instrument, RMMI.
abstract: BACKGROUND
  The respiratory movement measuring instrument (RMMI) is a method for examining the differences in anteroposterior diameter of the body during breathing.
  
  
  OBJECTIVE
  The aim of this study was to investigate the known group validity of the RMMI by comparing different body positions and breathing behaviours in healthy persons.
  
  
  METHODS
  The respiratory motion of the rib cage and the abdomen was measured by the RMMI in 40 healthy subjects. The measurements were undertaken in the supine and sitting positions and during normal, abdominal and thoracic breathing.
  
  
  RESULTS
  The proportion of rib cage motion was 36% in the supine and 52% in the sitting position (P<0·001). The proportion of rib cage motion in the supine position was 21% during abdominal breathing and 57% during thoracic breathing, both significantly different (P<0·001) in comparison to normal breathing.
  
  
  CONCLUSIONS
  The RMMI showed a high degree of validity concerning distribution of motion between the rib cage and abdomen.
authors.affiliation: Department of Physical Therapy, Sahlgrenska University Hospital, Gothenburg, Sweden. inga-lena.gunnesson@vgregion.se
authors.forename: Inga-Lena
authors.initials: IL
authors.lastname: Gunnesson
authors.forename: Monika Fagevik
authors.initials: MF
authors.lastname: Olsén
mesh_terms: D000005:Abdomen / Q000502:physiology; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D009068:Movement; D011187:Posture / Q000502:physiology; D015203:Reproducibility of Results; D012129:Respiratory Function Tests / Q000379:methods*; D015656:Respiratory Mechanics / Q000502:physiology*; D016683:Supine Position / Q000502:physiology; D013909:Thorax / Q000502:physiology; D014894:Weights and Measures / Q000295:instrumentation*