to be fair i did see videos/photos showing old school guys using rounded backs but i would not do it myself.
I have posted about the Jefferson deadlift and the controversy around it. It's typically not loaded heavily and some physical therapists say it's proper to strengthen all possible ranges while others think the spine should always be kept "neutral" when loaded.
I used to do these seated good mornings and you necessarily have to bend your back, I went as high as 420. Amazingly an MRI showed no herniations but "possible 'effect' on spinal bone marrow" or something to that effect, translating from Swedish here, which I don't know what it even means and my GP looking at the results couldn't explain either

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