Interestingly, I actually started snatch-grip rack pulls from mid-shin height almost by accident.
Ever since my knee surgery last year I've been on the lookout for good exercises to work the quads without pissing off my knee. Deadlifts are generally better tolerated than squatting and lunging variations, and I thought that using the snatch grip would be even better for the legs given the increased range of motion.
While that sounded good in theory, I found it damn near impossible to pull from the floor with any semblance of a flat back, especially as the weights got heavier. Given my history of lower back issues, I ruled that one out pretty quickly.
But when I tried doing them from mid-shin, using a snatch grip, I noticed the limiting factor was definitely the upper back, not the legs, making it a better back exercise than leg exercise in terms of muscle development.
In short, I'd accidently discovered an incredible back builder, one I predict will turn out to be the best movement, bar none, for back hypertrophy!
The secret here is in the name: snatch grip and mid-shin.
The wider grip puts significantly more stress on the upper back, traps, and rear delts than a conventional deadlift, while pulling from the pins with the bar elevated a few inches off the floor allows for better form and heavier loading than pulling from the floor.
Bear in mind though that using a wider snatch grip effectively increases the range of motion of the lift, so a snatch grip rack pull from a few inches off the floor is approximately equivalent to a conventional deadlift from the floor.
To that end, a snatch-grip deadlift from the floor is really more like a conventional deadlift done from a deficit, and while there's certainly nothing wrong with that, most people just don't have the requisite hip mobility to do it safely without rounding their lower back.
At the same time, you still want a decent range of motion, so don't go letting your ego get in the way and start pulling from the knees just so you can throw more wheels on the bar. When the bar is at mid shin level, the bottom of the plates will be just a few inches off the floor. That's it.
Reset after each rep to keep your form in check. Think about keeping your chest up to avoid rounding your back. With a super-wide grip, you won't actually be able to keep your chest up to any great extent, but thinking about it will at least ensure you keep a safe back position.
On the point of grip width, the wider your grip, the harder it'll be. Ideally the wider the better, but when pulling out of the rack you're limited by the width of the pins for obvious reasons (you don't want to crush your hands).
If you're fortunate enough to have blocks to pull from, that's a great option that will let you take a wider grip. If you're stuck in the rack, just grab as wide as you can while still giving your hands a few inches of leeway from the pins, just to be safe.
I think you'll definitely want to use straps on these because holding the bar is way harder with a snatch grip; otherwise you'll be significantly limited by grip strength. Our goal here is back development, so as the saying goes, "Wrap it before you tap it."
One more thing. Start light. I mean, really light.
And don't go doing a ton of volume the first time out. If you've never used the snatch grip before, it's a lot harder than you might expect, and I'm sure it'll also make you sore as hell.
In time you and I both will be able to build up to big numbers, but let's take it slow. If you fail to heed my warning, don't say I didn't warn you.
Now, go build a bigger back!