Background: The straight leg raise (SLR) is the most commonly applied physical tests on patients with sciatica, but the sensitivity and specificity ratings for disc hernia and neural compression leave areas for improvement. Hip internal rotation tensions the lumbosacral nerve roots and ankle dorsiflexion tensions the sciatic nerve along its course. We added these movements to the SLR (extended SLR=ESLR) as structural differentiators and tested inter-rater reliability in patients with LBP, with and without sciatica.
Methods: Forty subjects were recruited to the study by the study controller (SC), 20 in the sciatic group and in the control group. Two independent examiners (E1&E2) performed the ESLR and did not communicate to the subjects other than needed to determine the outcome of the ESLR. First, SLR was performed traditionally until first responses were evoked. At this hip flexion angle, a location-specific structural differentiation was performed to confirm whether the emerged responses were of neural origin. Cohen’s Kappa score (CK) for interrater reliability was calculated with sensitivity and specificity to detect sciatic patients was calculated.
Results: CK of the ESLR result between the independent examiners was 0.85. CK between SC/E1 was 0.90, and 0.95 between SC/E2. Sensitivity and specificity to detect sciatic patients were 0.95 and 0.98, respectively.
Conclusions: ESLR with the addition of location-specific structural differentiation is a reliable and repeatable tool in discerning neural symptoms from musculoskeletal in patients with radiating low back pain. We recommend adding these movements to the standard SLR with aim of improving diagnostic efficacy.