Upper back rounding in deadlift

Hi Mark,

I am an newly minted intermediate trainee whose results are consistent with the tables in PP. I am currently following a version of the texas method where I do rack pulls and halting deadlifts alternating weeks according to the approach you have described here previously. Rack pulls are progressing fine, but on the halting deadlift my weakness that keeps me from progressing is my upper/middle back: I have no problem separating the bar or finishing the movement, and my lower back always stays protected. However, my upper/middle back rounds noticeably after a few reps of halting deadlifts.

Questions: What can I do in terms of assistance exercises to remedy this? Is rows the only option? The amount of weight that can be rowed seems a lot lower of a stressor than what is needed to hold the upper back isometrically under a heavy load, so my worry is whether there is enough carryover. Is there some other approach I should take to remedy this?

Any feedback would be much appreciated.

I'm not a big fan of assistance exercises to fix problems with primary movements, especially those that use the muscles in different ways than primary exercise does. If your upper back is rounding during a pull, it's not holding a good isometric contraction. How about front squats with very strict form? I think you'll find that they work better than rows. Or just lower the DL weight to a point where you can just keep flat, and let that be a direct exercise for the upper back.