Thirty consecutive patients with clinical and radiographic findings consistent with lumbosacral root injury were evaluated. Electrodiagnostic examinations included determination of root mean square (Vrms)/turns (T) values. Vrms/T values >1 are consistent with chronic neurogenic injury and have been correlated with increase in fiber density. Radiographic studies were independently classified as having severe (group I; n= 8), mild (group II; n=11), or no lumbar spinal stenosis (group III; n=11). Abnormal Vrms/T values were present in all 8 patients in group I in comparison to 0/11 in group II and 2/11 in group III (p