Clinical evaluation of the sensitivity and induced pain pattern on passive straight leg raisng test in patients with lumbosacral root pain

Background: The straight leg raising test (SLR) is widely used to evaluate patients with sciatica. The SLR was evaluated in many previous studies; however, there is no agreement about the characterization of the test. Objective: To investigate the patterns of pain on passive SLR in patients with sciatica and to evaluate the effects of various maneuvers on this test. Study design: Case series study. Setting: Rheumatology division, Ibn Sinna Teaching Hospital, Mosul, IRAQ. Methodology: Seventy patients with unilateral sciatica for less than 2 years duration, there ages are between 20 to 50 years, were studied. A detailed history was obtained from the patients and they were subjected to full physical examination for their current problem. The SLR was performed, the angle of elevation was recorded and the effect of ankle dorsiflexion and maximal neck flexion was evaluated. After that, the SLR repeated but with lumbar flexion, the angle of the SLR was also recorded. Then crossed SLR was performed. Results: SLR was positive in 91.4% of cases. Ankle augmentation was positive in 95.3% of cases, while neck flexion increased pain in 28.1% only. Cross SLR test was positive in 17.1% of cases. Increased SLR angle by contralateral hip flexion was seen in 81.3% of cases; mean SLR angle with the contralateral hip extension was 47.8±12.4 degree, while contralateral hip flexion increased the mean SLR angle to 58.9±16.9 degree. The patterns of pain induced by SLR were: low back pain only in 50% of cases, leg pain only in 42.1% of cases, low back and leg pain in 7.9% only. Conclusion: The patterns of pain that were induced by passive SLR were: low back pain only, leg pain only, low back and leg pain. This could bear relation to the position of the prolapsed disc. The use of sensitizing maneuvers (ankle dorsiflexion, neck flexion) increases pain in patients with sciatica with positive SLR test, so we recommend the conduction of these maneuvers in patients with positive SLR. Measurement of SLR was influenced by the position of the contralateral hip (flexed Vs. extended).