Sensitivity, specificity and predictive value of the clinical trunk muscle endurance tests in low back pain.

OBJECTIVE: To describe the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of five clinical tests used to measure trunk muscle endurance in low back pain.
DESIGN: A cross-sectional non-experimental design.
SETTING: Orthopaedic and physical therapy departments of four hospitals and outpatient physical therapy clinics, Tehran, Iran.
SUBJECTS: Convenience sample of 200 subjects participated in this study. Subjects were categorized into four groups: men without low back pain (N = 50, mean (SD) age = 38 (12) years), women without low back pain (N = 50, mean (SD) age = 43 (11) years), men with low back pain (N = 50, mean (SD) age = 39 (12) years) and women with low back pain (N = 50, mean (SD) age = 43 (12) years). MAIN MEASURES: Five clinical static endurance tests of trunk muscles such as: Sorensen test, prone isometric chest raise test, prone double straight-leg raise test, supine isometric chest raise test and supine double straight-leg raise test were measured in each group.
RESULTS: The result of receiver operating characteristics (ROC) curve analysis revealed that in a separate analysis of data for men and women, among all tests, the prone double straight-leg raise test had the highest sensitivity, specificity and predictive value in low back pain compared with other performed tests.
CONCLUSIONS: It seems that the prone double straight-leg raise test has more sensitivity, specificity and predictive value in low back pain than other tests and could be used as a useful clinical method for testing the spinal muscle endurance to predict the probability of the occurrence of low back pain.