Aerobic fitness, pain, function and disability in chronic low back pain patients

The purpose of this study was twofold: to investigate which of three commonly used exercise tests best reflects the level of aerobic fitness in chronic low back pain (CLBP) patients and to investigate the relationship of aerobic fitness with pain, physical functioning and disability using a cross-sectional study.;This study is important because treatment of CLBP patients is based on the assumption that CLBP patients have low levels of aerobic fitness and that relationships exist between aerobic fitness, pain, physical functioning and disability. The sample consisted of 22 males and 28 females with a mean age of 39.3 years and 40.1 years respectively.;The treadmill test yielded higher VO2max (aerobic fitness) than either the bicycle or upper extremity exercise tests. Despite pain, CLBP patients had aerobic fitness levels comparable to healthy subjects. Test retesting of aerobic fitness was reliable. Prediction equations for levels of aerobic fitness of the CLBP patients were similar to those found in healthy subjects when using age as a predictor variable. Pain intensity and pain with movement had no relationship with aerobic fitness.;Physical functioning was positively related to actual and predicted aerobic fitness levels. Walking ability increased with higher aerobic fitness. Aerobic fitness was not associated with disability as measured by work status. Self reported limitation of sex life, sometimes considered a social disability, was less with higher levels of aerobic fitness. General health was weakly related to measured levels of aerobic fitness. There was no relationship between aerobic fitness and psychological variables.;In conclusion, the treadmill test best reflected levels of aerobic fitness in CLBP patients. Given the strong relationship of aerobic fitness with physical functioning and disability it is important for future research to investigate if interventions aimed at changing aerobic fitness levels have a positive impact on function and disability. Several fundamental tenets in the treatment of CLBP patients, that they have lower aerobic fitness than healthy people and that aerobic fitness is associated with pain, can be questioned.