title: The 6-min push test is reliable and predicts low fitness in spinal cord injury.
abstract: OBJECTIVE
  The objective of this study is to assess 6-min push test (6MPT) reliability, determine whether the 6MPT is sensitive to fitness differences, and assess if 6MPT distance predicts fitness level in persons with spinal cord injury (SCI) or disease.
  
  
  METHODS
  Forty individuals with SCI who could self-propel a manual wheelchair completed an incremental arm crank peak oxygen consumption assessment and two 6MPTs across 3 d (37% tetraplegia (TP), 63% paraplegia (PP), 85% men, 70% white, 63% Hispanic, mean age = 34 ± 10 yr, mean duration of injury = 13 ± 10 yr, and mean body mass index = 24 ± 5 kg.m). Intraclass correlation and Bland-Altman plots assessed 6MPT distance (m) reliability. Mann-Whitney U test compared 6MPT distance (m) of high and low fitness groups for TP and PP. The fitness status prediction was developed using N = 30 and validated in N = 10 (validation group (VG)). A nonstatistical prediction approach, below or above a threshold distance (TP = 445 m and PP = 604 m), was validated statistically by binomial logistic regression. Accuracy, sensitivity, and specificity were computed to evaluate the threshold approach.
  
  
  RESULTS
  Intraclass correlation coefficients exceeded 0.90 for the whole sample and the TP/PP subsets. High fitness persons propelled farther than low fitness persons for both TP/PP (both P < 0.05). Binomial logistic regression (P < 0.008) predicted the same fitness levels in the VG as the threshold approach. In the VG, overall accuracy was 70%. Eighty-six percent of low fitness persons were correctly identified (sensitivity), and 33% of high fitness persons were correctly identified (specificity).
  
  
  CONCLUSIONS
  The 6MPT may be a useful tool for SCI clinicians and researchers. 6MPT distance demonstrates excellent reliability and is sensitive to differences in fitness level. 6MPT distances less than a threshold distance may be an effective approach to identify low fitness in person with SCI.
authors.affiliation: The Miami Project to Cure Paralysis, Department of Neurological Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA. rcowan@med.miami.edu
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Cowan
authors.forename: Morgan K
authors.initials: MK
authors.lastname: Callahan
authors.forename: Mark S
authors.initials: MS
authors.lastname: Nash
mesh_terms: D000328:Adult; D001132:Arm / Q000502:physiology; D015992:Body Mass Index; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D010101:Oxygen Consumption / Q000502:physiology; D010264:Paraplegia / Q000503:physiopathology; D010809:Physical Fitness / Q000502:physiology*; D011782:Quadriplegia / Q000503:physiopathology; D015203:Reproducibility of Results; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D055815:Young Adult