Portal de Periódicos da CAPES

MAXIMAL VERSUS SUBMAXIMAL TESTING PROTOCOLS TO EVALUATE FITNESS OF PATIENTS WITH CHRONIC LOW BACK PAIN

2002; Lippincott Williams & Wilkins; Volume: 34; Issue: 5 Linguagem: Inglês

10.1097/00005768-200205001-01515

1530-0315

Henri Nielens, delphine cornet, F Rigot,

Musculoskeletal pain and rehabilitation

PURPOSE: Maximal testing protocols including direct VO2max measurements are often implemented in patients with low back pain to evaluate cardiorespiratory endurance (CRE). The validity of such testing procedures may be questioned since such patients may be reluctant to achieve true maximal effort. The aim of this study is to compare maximal oxygen uptake (VO2max) measured at the end of a maximal testing protocol to VO2max estimation obtained with a submaximal protocol in patients with chronic low back pain as compared to controls. METHODS: Eleven patients with chronic low back pain and 10 age- and sex-matched controls achieved in a random order 2 cycle ergometer tests designed to evaluate VO2max. The first protocol is a maximal multistage gradational cycle ergometer test. During this test, heart rate (HR), oxygen uptake, respiratory gas exchange ratio (RER) and rate of perceived exertion (RPE) are recorded at the end of each stage. All the subjects are asked to perform maximally. The second testing protocol is the Astrand 6-minute submaximal testing protocol which allows VO2max estimation using the Astrand's nomogram. In patients, pain scores are also obtained before the tests and at the end of them. RESULTS: In controls, there is no difference in VO2max according to the testing protocol. In patients, mean VO2max measured at the end of the maximal test is 20% lower as compared to the value obtained with the Astrand test (paired t = 3.18; p < 0.01). Mean HR and RER collected at the end of the maximal test are significantly lower (p = 0.03 and < 0.01, respectively) in patients suggesting only submaximal effort. However, mean RPE value scored by the patients at the end of the maximal test is not different from controls. Pain scores obtained from patients at rest before the tests are not significantly different. The increase of pain after the maximal test was very significantly higher (paired t = 3.32; p < 0.01). CONCLUSION: Maximal testing protocols may lead to a systematic underestimation of aerobic capacity of patients with pain. They are thus probably not valid to evaluate CRE of such subjects. Moreover, they are often responsible for a significant pain increase which make them generally unsuitable for routine clinical use.