When someone has a lumbar HNP we perform the slump test, if it reproduces their pain it is considered a positive test for HNP as it irritates it. (side note - if the person points to their SI as source of pain in slump test you are usually just shearing their SI in my experience and it is a false positive, but you can confirm with my SI diagnostic procedure and then retest) When someone has an HNP in the neck and you do nerve gliding you are just irritating the disc! Listen...