Romanian Deadlift vs. Rack Pull for lower back

Back extensions/weighted back extensions.

https://www.youtube.com/watch?v=ph3pddpKzzw

I had a really tough time when I started deadlifting..within a few months of incorporating back extensions in training, my deadlift jumped from 255-310. Sitting at 355 (6-8 reps/3 sets) at the moment and still use extensions to keep the lower back strong. They help a ton. You can grab a 10 or 25lb plate and holding it across your chest to increase overload.

Also Sumo squats too..because you're going straight up and not at an angle, there isn't as much strain on your lower back

RDL's are a glute/ham exercise more than anything else. Rack pulls, done properly, aren't really very good for your lower back either. If you want to work on your erectors, you want something like weighted hyperextensions or good mornings, maybe.

I don't know...I feel it there. So it's targetting that area for sure. I think it depends what you activate.

But all I was really wondering, is whether Rack pulls and Romanian deadlifts are nearly equivalent.

Or were you trying to say they're downright bad for the lower back?

I'm saying that the training effect on your lower back from these lifts is secondary, at best, and can be better achieved with other exercises, like the weighted extensions or good mornings. You want a long lever arm from your waist to the added weight, and you want the front of your pelvis supported to isolate the force generated as being as much from your spinal erectors as possible.

In the rack pull, ideally you are already largely done with the back extension part of the lift the higher you get out of the hole. Your back angle only decreases as you go up, and you finish with your hips. If you're doing something like a stiff-legged deadlift out of a rack, that's different than just a plain ole rack pull.

RDL's start at the top and stop a little high. Given that you're free-floating, there is nothing discouraging you from incorporating your *kitten* and hammies into the lift (which are the main muscles that the RDL and SLDL are usually used to train).

Roman chair/back extensions/hypers (all largely the same thing) will concentrate the effort a bit more in the erectors.
Good mornings can also be a glute exercise, but the longer lever arm than an RDL makes the erectors more dominant.

TBH, I can't imagine why you don't just deadlift, but you said you don't want to, so that's that, I guess.

Sumo squats I don't see being all that helpful to train the lower back. As you said, the torso is at a more vertical angle, so lower back is LESS involved.

Neither will give superior overall development to the deadlift (the deadlift without words in front of it).

I tried rack pulls and loved them over regular deadlift. My main goal is building lower back strength right now. The full deadlift is a waste of movement for my purpose right now. I'll graduate to it after I gain the lower back strength I want.

But without a rack, I can no longer do rack pulls. I invented what I thought was a partial deadlift, but then found out it was called the Romanian Deadlift. To me, it seems almost equivalent to the rack pulls, except there is no hard stop at the bottom. Conventional wisdom is to always use a full range of motion for all exercises, but I think the Romanian deadlift is pretty awesome since I don't have a rack.

Will this accomplish what I want? Or do I have to find a way to do rack pulls to emphasize lower back? The Romanian version seems to engage stabilizers a bit more, and also stretch everything a bit more since there's no hard stop at the bottom. I want ab development too, and I definitely feel it there more than with rack pulls.

I'm keeping it light and with good form, so I'm not concerned about herniation or vertebral compression.

We do rack pulls on one of our back days...but don't think the bar is quite low enough. I was contemplating doing them the other way you mentioned, but was also not sure if they'd be as effective, or do the same thing. I can't imagine they wouldn't?