Of all patients with low back pain (LBP), 85% are diagnosed as “non-specific lumbar painâ€. It has been postulated that the only reliable test is a straight leg raise test for detecting sciatic pain, and for other diagnostic subgroups, tests are of varying value. Only a few standardized tests exist to test function, inspection, mobility, pain, muscle flexibility or stability for patients with early phase lumbar spine and sacroiliac joint pain and dysfunction in the non-laboratory setting. The aim of this study was therefore to examine the inter- and intra-tester reliability of selected standardized clinical tests. Fifteen eligible, consecutive and voluntary LBP patients (aged 18–56 years), whose pain had lasted less than 3 months were recruited by an invitation letter. Patients were examined by two physiotherapists specialized in orthopaedic manual therapy. These PTs examined the same patients at a 1-week interval, changing the examination order at the second session. The assessment consisted of seven categories: history, observation of posture, function of low back and lower extremities, stability tests, pain provocation and mobility tests, neurological and neurodynamic tests, and tests of muscle tightness. In analysing these seven test categories, the mean inter-tester kappa was 0.5 (95% CI –0.05 to 1.20) and intra-tester kappa 0.6 (95% CI –0.40 to 1.28). Overall inter- and intra-tester reliability was at an acceptable level, except for the inspection test category, where agreement was poor. However, the reliability of individual tests ranged from poor to very good.
In conclusion, when assessing LBP patients in the early phase (<12-week duration), reliability of one or more tests were acceptable on a group level with inter- and intra-tester reliability in every test category. However, these results need confirmation in a larger sample, especially when this great number of examination findings is tested, to reduce the likelihood of spurious findings.