Yeah, although neutral to flexion is fine for a lower back for a squat or a deadlift. In fact, with a heavy weight, good luck NOT flexing your lower back on a

Yeah, although neutral to flexion is fine for a lower back for a squat or a deadlift. In fact, with a heavy weight, good luck NOT flexing your lower back on a deadlift or at the bottom of a squat. The 'upright' squat you described is an Olympic lift variation - called highbar squat. I was going to send a link over but I hesitate to toss a random article or video (some of which are crap). But it's probably easy to watch an Olympic lift video from the olympics, as that's the cream of the crop. A squat positioning with more of a hip hingeing is more of a Powerlifting squat. I can definitely recommend Rippetoe's explanations here https://www.youtube.com/watch?v=QhVC_AnZYYM https://www.youtube.com/watch?v=QhVC_AnZYYM even though I myself do high-bar. As you can see (especially as explained in the video), the bar positioning plays a role in how upright your back is as you squat (since you mentioned that aspect). It's because of the center of gravity and the straight-path of the bar. It's obvious if you see an illustration of the bar path and these positions. However, a 'neutral' back, I don't know, I'd call it more of a flexed back (which may be neutral under load). A neutral back might be more of a gymnastics-specific thing. Regardless, core strength (meaning lower back, abs and obliques, among other things) is VERY important here.