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.