• The pain pattern of patients with upper lumbar root lesions can be elicited by a simple diagnostic test called bentknee pulling, in which the examiner pulls the half-prone patient's bent knee backward while putting forward pressure on the buttock. The technique was tested in seven patients with either clinically, myelographically, or electromyographically demonstrated L-3 and/or L-4 root lesions, and it successfully reproduced the pain in all seven patients. In all patients the result of straight-leg raising was negative.