Here is one of my favourite raw lifers. Konstantinov pulling 380 kg for 4 reps.
You would never teach someone to deadlift like this. But when you look at his form he does all of the things I talk about.
– relaxed set up but tight at the bottom
– uses his legs
– bar close to body
– drives with his hips
etc etc etc.
The round back is something your average PT will look at and say no way. Your average PT is a pussy who either doesn’t deadlift or who maxes out on 120 kg. That’s what Konstantinov weighs. He has a back of steel and I don’t expect he will be having too many back issues.