The function of disordered lumbosacral nerve roots in cases of transitional vertebrae was studied from the viewpoint of neurological findings.
There were 25 cases who had a single neve root disorder. The level of the transitional vertebrae (T. V.) was calculated from the cephalic side, which were classified into 2 groups; (1) S Type (lumbar number 4+T. V.), (2) L Type (lumbar number 5+T. V.). The function of the transitional nerve roots were S type in 10 cases and L type in 15 cases In addition there were a lot of mixed nerve root disordered cases which were composed of both L5 and S1 factors.
Moreover in the L type, the function of the transitional nerve roots was influenced by the shape of the transverse process and the level of the iliac crest.
From these results, it was suggested that the function of the nerve roots was influenced by the shape of the bone.
