Physical Therapy (94)

Aerobic fitness testing in patients with chronic low back pain—Which is the best test? (New England Medical Center, Boston, MA) Spine 2000;25:1704–1710. In this study, 30 participants with chronic low back pain performed three symptom‐limited maximal exercise tests: a treadmill, an upper extremity ergometer, and a bicycle ergometer. The tests were administered in randomized order. Heart rate was continuously monitored and oxygen consumption in terms of mL/kg/minute was measured by indirect calorimetry each 30 seconds. The statistical difference among the tests was highly significant ( P < 0.0001). The treadmill test yielded the highest peak and predicted oxygen consumption followed by the bicycle and the upper extremity ergometer test, respectively. Conclude that the treadmill test is the best test for measuring aerobic fitness levels in patients with chronic low back pain. It yielded the highest peak oxygen consumption compared with the other tests, coming closest to measuring maximal oxygen consumption. Comment by Karen Crawford, RPT. Aerobic conditioning has been a component of several treatment approaches in the reduction of back pain disability. The specific contribution of aerobic fitness achieved through these approaches is not always known. Chronic pain patients tend to be inactive. As a result of this inactivity muscles become inefficient at using oxygen and this results in a loss of muscle endurance and cardiac output. The purpose of this study was, 1) to determine which testing protocol yields the highest peak values of VO 2 , heart rates, and respiratory changes ratio in a sample of patients with CLBP; 2) to determine whether the VO 2 measures between the tests are significantly different from each other; 3) to determine which factors limit performance in each of these tests; and 4) to compare values of peak VO 2 and predicted VO 2 max with aerobic fitness values published for normal subjects. Chronic low back pain was defined as pain persisting for 3 months or more. Patients were excluded from this study if they were taking medications that influenced heart rate or blood pressure or if they had coexisting major medical disease, amputations of one or more extremities, or acute upper or lower extremity muscular skeletal pain that would interfere with exercise testing or acute psychiatric illness. Thirty participants with chronic low back pain performed 3 symptom limited maximal exercise tests: a treadmill, upper extremity ergometer, and a bicycle ergometer. These tests were randomly administered and heart rate was continuously monitored along with oxygen consumption. Of the 3 tests, the treadmill test is the most functional because of its uses in walking, a function of everyday life. This advantage to bicycle testing is that most Americans are unaccustomed to bicycle riding. Many of the patients reported increased burning in the thigh and buttocks for sitting on a hard saddle. Most clinics have access to a treadmill making this a practical test. The treadmill test is, thus, the best measure of cardiovascular performance; deconditioning of these patients expressed itself as early fatigue of peripheral muscles due to inactively, and limiting their performance on the bicycle and UBE test.