Some powerlifters do intentionally rounded back good-mornings. Many would say this is insanity, but maybe the risk is overblown if the load is increased slowly. Some powerlifting "stabilizer" moves:https://www.instagram.com/p/B8fFetUJpki/?igshid=1e85dfrmusx6nhttps://www.instagram.com/p/B3BBKVchIAE/?igshid=hkiquiwblexp
Does this make any sense at all? The lower back comes very much into play when doing squats and deadlifts. I know this because if you have a sore back you can't do these movements. https://ergo-log.com/powerlifting-makes-your-muscles-stronger-but-not-the-muscles-in-your-lower-back.html