Significance of the straight-leg-raising test in the diagnosis and clinical evaluation of lower lumbar intervertebral-disc protrusion.

The cases of 113 patients who had protrusion of a lumbar intervertebral disc were analyzed to determine the relationship between the findings at operation and the location of the pain that resulted from the straight-leg-raising test. The study showed a close relationship between the location of the pain and the position of the protrusion of the disc. The degree of limitation of straight-leg raising was also found to have a direct relationship to the size and position of the protrusion and to its relationship to the spinal nerve. The protrusions were classified into three types according to position in relation to the dura mater and to the pattern of pain that was induced by passive straight-leg raising. On straight-leg raising, central protrusions tended to cause pain in the back, lateral protrusions caused pain in the lower extremity, and intermediate protrusions caused both. On this basis, the distribution of pain on straight-leg raising allowed an accurate prediction of the location of the lesion in 100 (88.5 per cent) of the 113 patients.