The usability of a modified Astrand bicycle test to assess the aerobic capacity in patients with musculoskeletal pain and healthy controls.

Abstract

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. 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. 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. 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.