extended spine in heavy deadlift?

[spiderman]

I recorded myself doing a 1RM deadlift today (405 lbs) and I noticed my back (lumbar and thoracic) goes into minor flexion. It is very minor.

I'm having a difficult time imagining someone doing a 1RM 600 lbs deadlift maintains hard back extension.

Does anyone actually do a 1RM deadlift with their back in real extension or is that just a myth that we are all supposed to try to achieve but no one actually does?

[Tom Campitelli]

A true 1 RM effort will always suffer from a little form breakdown. You will often see some rounding on really heavy deads, especially of the thoracic spine. You will also often see some low back rounding. However, it is possible to pull over 1,000 pounds with a pretty damn flat low back. Benedikt Magnusson did so, although you will note his upper back is slightly rounded. A little flexion at maximum attempts is nothing to get upset over. Try and make your sets of five as solid as you can.

[Kregna]

Hi Tom

At what point do you not allow the upper rounding to continue? If pain occurs?

[Tom Campitelli]

This is very much a feel thing. Pain is signal that something is wrong, but I would probably stop someone before that point. I don't have a well defined criteria except for "It should not round much." You don't want to consciously round your upper back, at least for general training purposes. It is actually somewhat difficult for many people to round their upper backs enough to cause an injury. Lower backs are another story.

[OCG]

Personally, I can feel when my low back rounding and/or looseness starts effecting my pull. It feels off in several significant ways, it feels inefficient and squishy and I don't feel like I'm in the right position.

I know that with a light enough weight (anything I'm using for reps basically) if I keep my low back in good extension (and with any weight I'm going to rep this is mostly a form issue) and my upper back appropriately squoze that my upper back won't round much if at all, but I never worry about it and I don't know anyone with a big pull who does.