My deadlift isn't the lightest at 3*6*150Kgs, but afterwards my lower back feels like it's been hit by a wrecking ball, and my quads feel almost no strain. I notice during squats a certain weakness below around parallel, which fades when I move a degree beyond (either up or down), so I suspect my lower back is fundamentally weaker than the rest of me, and the inordinate pain is simply due to being pushed so much harder, proportionally.
I've checked my form, perfectly straight back (I start with an arch but it's flattened out), feet under the bar, I don't stick my backside out any further than needed, I actively lower the weight below the knee just with my legs...but despite all this, my lower back is crying yet my quads are laughing. I think my lower back just needs strenghtening - otherwise, no injury there ( to my knowledge), no history of pain etc. It's just, simply, WEAK.
Would you agree with this assessment, and if so, should I continue to Deadlift heavy? Or find a remedial exercise to bring it up to standard?