Deconditioning in patients with chronic low back pain: fact or fiction?
Prospective case series with historical controls (normative data). To compare aerobic fitness levels in patients with chronic low back pain with those published on a sample of 295 healthy subjects. Clinical belief holds that patients with chronic low back pain have low fitness levels as a result of inactivity because of pain. Because few studies have investigated the level of aerobic fitness in these patients, however, it remains unclear how fitness levels in patients with chronic low back pain patients compare with those published a sample of the normative population. A sample of 50 patients with chronic low back pain with a mean pain duration of 40 months referred to an outpatient pain clinic performed a symptom-limited modified treadmill test. Aerobic fitness levels were determined by indirect calorimetry to measure oxygen consumption (VO2). Predicted maximum oxygen consumption (VO2max) levels were calculated for all subjects. Multiple regression analysis with adjustment for age and sex yielded prediction equations for men and women separately. Ninety-five percent confidence intervals were calculated for predicted mean oxygen consumption (VO2) and the slope of the equations. These were compared to established prediction equations on healthy subjects. Prediction equations for estimated maximum oxygen consumption (VO2max) in patients with chronic low back pain equal those in healthy sedentary men and active women. Levels of aerobic fitness in patients with chronic low back pain are comparable with those in healthy subjects.