Relationships between spinal mobility, physical performance tests, pain intensity and disability assessments in chronic low back pain patients.

Correlations between the Oswestry Disability Questionnaire (ODQ), the Pain Disability Index (PDI), PDI subscales PDI factor 1 (PDI 1), PDI factor 2 (PDI 2) and visual analogue scale (VAS) pain intensity on the one hand and spine range of motion measures and static and dynamic functional performance tests on the other,were studied in 52 chronic low back pain patients. Comparable groups of male and female patients were studied. A moderately significant (p < 0.01) inverse correlation was observed between the ODQ and rotation to the left even after correction for age, but not when men and women were studied separately. A significant (r = -0.480, p < 0.001) inverse correlation was observed between the repeated squatting test and pain intensity and in men both pain intensity and disability correlated (r = -0.607, p < 0.001) with this particular test. Only for the women were there moderately significant (p < 0.01) inverse correlations between disability assessments and all the physical performance tests with the exception of the static back muscle test. In the women only the isometric lifting test showed a moderately significant inverse correlation (r = -0.504, p < 0.01) with pain intensity. Such apparent gender differences in the overlap between physical performance tests and self-report disability assessments and pain intensity may be clinically relevant. The results will, however, require confirmation on larger groups of chronic low back pain patients.