title: The usability of a modified Astrand bicycle test to assess the aerobic capacity in patients with musculoskeletal pain and healthy controls.
abstract: OBJECTIVE
  The aim of this study was to assess the usability of a modified Astrand bicycle test in subjects with musculoskeletal pain disorder (MSPD) and healthy controls.
  
  
  METHODS
  In a random cross-over design, 31 subjects with a MSPD who have been referred to rehabilitation medicine and 33 healthy subjects matched for age, gender, height and body weight, performed an Astrand bicycle test and a modified test with a time interval of 7 days. Drop-out rates, VO2max values (in mL/kg lean body mass (LBM) min(-1)), intraclass correlation coefficients (ICCs) and critical difference (Bland-Altman plots) for both tests within each group of subjects were compared.
  
  
  RESULTS
  The drop-out rate in both tests for the MSPD group was comparable, and mainly caused by pain, fatigue or breathlessness. Compared with the modified version, the Astrand test showed higher VO2max-scores: 4.83 mL/kg LBM min(-1) (9.96%) in the MSPD group and 3.5 mL/kg LBM min(-1) (5.57%) in the healthy group. ICCs were 0.79 and 0.87 and the limits of agreement were 8.5 mL/kg LBM min(-1) (15.9%) and 10.2 mL/kg LBM min(-1) (18.1%), respectively.
  
  
  CONCLUSIONS
  The usability of the modified test is acceptable, as well as in healthy individuals as subjects suffering from MSPD being referred to rehabilitation medicine. However, a slight under estimation of VO2max with the modified test has to be taken into account.
authors.affiliation: Rehabilitation Foundation Limburg, Knowledge Centre, Hoensbroek 6430 AB, The Netherlands. rsmeets@srl.nl
authors.forename: Rob Johannes
authors.initials: RJ
authors.lastname: Smeets
authors.forename: Mirelle Van
authors.initials: MV
authors.lastname: Soest
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D018592:Cross-Over Studies; D005080:Exercise Test / Q000295:instrumentation*; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000503:physiopathology* / Q000534:rehabilitation; D010101:Oxygen Consumption / Q000502:physiology; D010146:Pain / Q000503:physiopathology* / Q000534:rehabilitation; D018709:Statistics, Nonparametric