Confiabilidade e validade de construto do teste de marcha estacionária de dois minutos em indivíduos com lombalgia crônica inespecífica

Abstract

Introduction: Nonspecific chronic low back pain is defined as pain and/or discomfort located in the lumbosacral region, with or without irradiation to the lower limbs. Considered the most common form of low back pain, representing approximately 90 to 95% of cases, this term is used when its etiology cannot be determined. Objective: To evaluate the test-retest and inter-examiner reliability and construct validity of the two-minute step test (2MST) in patients with nonspecific chronic low back pain. Methods: The sample consisted of 37 patients, aged between 18 and 45 years, both sexes, with complaints of chronic low back pain. The interval between test and retest was 7 days. Analyzes of intraclass correlation coefficient (ICC), 95% confidence interval, standard error of measurement and minimum detectable change were performed. After identifying the non-normality of the data distribution using the Shapiro-Wilk test, we used the Spearman correlation coefficient to verify the magnitude of the correlation between the 2MST and measures of pain and physical activity. Therefore, the 2MST was correlated with the other instruments used in the study: Numerical Pain Scale (NPS), Roland Morris Disability Questionnaire (RMDQ), Catastrophic Thoughts about Pain Scale (CTPS), Tampa Scale for Kinesiophobia (TKS), Baecke Habitual Physical Activity Questionnaire (BQ). Results: Most of the sample was composed of women, with overweight and low back pain for more than 64 months. The 2MST showed excellent test-retest (ICC = 0.903) and inter-examiner (ICC = 0.925) reliability. The sport domain of the BQ correlated significantly with 2MST (rho = 0.444). Conclusion: The 2MST is a reliable measure to measure the functional capacity of patients with nonspecific chronic low back pain when considering different times and evaluators. Furthermore, this test correlates with sport-related physical activity.