The Modified - Modified Schober Test for range of motion assessment of lumbar flexion in patients with low back pain: A study of criterion validity, intra- and inter-rater reliability and minimum metrically detectable change

Purpose. The objective was to estimate the psychometric properties of the Modified - Modified Schober Test (MMST). Design. This study compared range of motion measurements of lumbar flexion in low back pain (LBP) patients using the MMST with measurements calculated on X-rays as the gold standard, and compared the measurements taken by two independent examiners. Method. This study was conducted at the main hospital in the Outaouais area, Quebéc, Canada. Thirty-one subjects with LBP from private and public clinics participated in the study. After a warm-up session, measurements with the MMST were taken in neutral position and an X-ray technician took an exposure in the same position. Results. Pearson's correlation test (r) between measurements made with the MMST and the gold standard, intra-class correlation coefficient (ICC), minimum metrically detectable change (MMDC) and confidence interval (CI) were used to analyze the data. The MMST demonstrated moderate validity (r = 0.67; 95%CI 0.44 - 0.84), excellent reliability (intra: ICC = 0.95; 95%CI 0.89 - 0.97; inter: ICC = 0.91; 95%CI 0.83 - 0.96) and a MMDC of 1 cm. Conclusions. In our sample of LBP patients, the MMST showed moderate validity but excellent reliability and MMDC.