The Slump test is a great test for someone with a nerve injury. I do it on every LBP/radic patient. BUT, When someone has SI Jt dysfunction, a lot I find, say yes that hurts my back, but when you ask them to point where, they point to their SI joint. Perform my SI diagnostic method and realignment and recheck the Slump test, a lot of times my patients have a negative Slump Test because when you performed hip flexion you were shearing their SI causing pain. Don’t get tricked! Please read my FREE SI paper with diagnostic, realignment procedure and protocol https://www.medcentral.com/pain/spine/low-back-pain/root-cause-sacroiliac-joint-dysfunction-four-step-exercise-protocol