If that’s 68%, yea I wouldn’t want to see 95%.
The lumbar region as a whole is rounded, I wouldn’t blame it on thoracic extensor weakness although it’s never a bad idea to improve upper back and lat strength/hypertrophy. My roommate has a very similar pulling style to this except with 620 unequipped and he can do pullups for reps at 240 lbs.
IME most pulls of this type are caused are a form issue first and foremost. Most people can’t tell whether their lumbar spine is rounded or not- the fancy word is kinesthetic sense. This is especially true with people who’ve had APT (which you’ve stated) or PPT less commonly, the glutes tend to become underactive and the lumbar spine take over a roll in both lumbar flexion and extension. Your lockout looks clean so I’m incline to believe it’s mostly the hip flexors and form.
Bottom line is, keep stretching your hip flexors and work on your form consistently. Like Dan John likes to state, if it’s not worth doing everyday then it’s not worth doing it at all. My pulls were always good but I rounded big time on hitting depth with squats, I did reps with an empty bar arching as tight as possible and doing hip mobility work and lo and behold I was fine in a couple months. Supermans are a good drill to teach you what a tight and arched spine will feel like.
Keep video taping your lifts and working on it.[/quote]
You’re right about it being initially a form issue - when I first started deadlifting I had NO idea what I was doing, and the entire lift was spinal extension - I didn’t even try to get my hips low. For a couple of years I encouraged really bad form by repeating it over and over.
I’m curious what hip mobility work you did. Currently I’m doing lots of hip flexor and rectus femoris stretching, static abductor and adductor stretches, bird dogs, fire hydrant circles, forward and side leg swings, dynamic hamstring stretches, and glute activation (bridges and x-band walks). It seems to be working alright, especially the glute activation. Three or four weeks ago my lockout would have looked horrendous.
Also, this may sound ridiculous, but do you think it’s possible to static stretch the lumbar erectors in order to inhibit them? It seems like static stretching might not be appropriate for all muscle groups, and I think the spinal erectors might be one such muscle group.