You're seeing the spinal flexion because you're not setting your back hard enough. You're rushing through step 4. What cues are you giving yourself to set your back?
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this was my last backoff set on heavy day, so this is about as fatigued as I ever am throughout the training week.
these are alright, right guys? Nothing big to be worried about, right?
In terms of minor things, I see that the first rep jumped forward a centimeter or two as it broke off the floor, probably because I jerked it a tad. Also a fair bit of spinal flexion, but probably not enough to be worried about.
You're seeing the spinal flexion because you're not setting your back hard enough. You're rushing through step 4. What cues are you giving yourself to set your back?
I just sort of focus on squeezing my shoulder blades together and tilting my pelvis forward ever-so-slightly, just until everything feels nice and lined up.
What cue would you have me use?
The cues are "squeeze chest up" and "take the slack out of the bar". Thoracic extension is the goal, not scapular retraction.
Check the technique sticky. "We need to see where you put your feet / hands / knees..." Posting to the Technique Forum
The pull is starting with your shoulders too far forward. which results in the bar moving forward and hips moving back as the bar breaks. "Rock back" to midfoot before the pull. Note: before the pull and not to initiate the pull.
Wasn't trying to be an ass, but the cues you listed above of "squeezing my shoulder blades together" and "tilting my pelvis forward ever-so-slightly" did not sound like anything I have seen mentioned in the books or anywhere on this forum for deadlift setup cues so I assumed you had not seen it. I generally think about "chest up" or pointing my chest at the wall for thoracic extension and now (thanks to the video I posted above) try to shove my belly between my knees to produce lumbar extension. I would certainly not describe this movement as "ever-so-slightly" tilting my pelvis as I find it very difficult to get tight and into this position at the bottom of the pull.