Assessments of lumbar flexion range of motion: intertester reliability and concurrent validity of 2 commonly used...

Cross-sectional.

To compare intertester reliability and concurrent validity of 2 frequently used methods for assessing lumbar flexion range of motion: the fingertip-to-floor distance (FFD) test and the modified Schober (mSchober) test.

An assessment of lumbar flexion range of motion is often incorporated in the clinical evaluation of patients with low back pain, as well as in clinical studies when examining the effects of different therapies on these patients. In both cases, the validity and reliability of assessment methods are important.

The FFD test and the mSchober test were used in a heterogeneous study sample (n = 98) including patients with low back pain, pelvic girdle pain, and individuals without pain in either of these areas. Each participant was examined by 2 of 3 randomly selected assessors on the same day. Intraclass correlation coefficient3,1, together with the Bland and Altman plot, were used to examine intertester reliability. Absolute reliability was calculated by the smallest detectable change. The relationship between the 2 tests was measured using Pearson correlation coefficient (r), which was used as the measure of concurrent validity.

The FFD test and the mSchober test showed an intraclass correlation coefficient of 0.93 and 0.77, and a smallest detectable change of 9.8 and 1.8 cm, respectively. There was a medium negative correlation between the 2 tests; an increase in the mSchober test resulted in a decrease in the FFD test (r = -0.47, P ≤ 0.001).

In our heterogeneous study sample, the FFD and the mSchober test showed excellent intertester reliability but with a relatively large smallest detectable change. However, the medium correlation between these 2 tests to measure lumbar flexion range of motion indicates that they do not fully assess the same phenomenon and hence should be used in combination when examining patients.

2.