Any criticism or advice would be well appreciated. Thanks!
Get your back more flat and don’t let your knees track forward. I’d also suggest not dipping into a sumo pull. I used to do that and recently made the switch based on recommendations I got on here, my form since has been much more consistent.
I agree that you should focus on having a flat back. For some, packing the neck and looking slightly downward can help with holding that neutral spine position. Doing RDLs can also help with creating the muscle memory to hold the correct position throughout the lift. If you do RDLs, start off with light weights and make sure you don’t go so low that you lose upper body tightness.
Nothing but red lights after the first rep. To help with the lock out, squeeze your ass at the top of the lift like your trying to hump the bar (gayest sentence I have ever written).
The weight doesn’t look too heavy for you, I just think your going about it a little haphazardly. Get your back tight, push your knees out (spread the floor). Focus on technique and don’t worry about the weight until competition.
Not a bad start, try pulling your shoulders down and getting your chest up. Be a little more patient getting the weight off the ground so you dont sacrifice your starting position. The sumo pull is very technical and requires you to commit to the pull and keep your positioning. If the weights were heavier I believe you would have been in a worse position so your strength lies in technique.
The movement should be through the HIPS, not the spine.
I agree with matias95 that you will need to learn to hip hinge. You can do this by placing most of your weight on your heels and pushing the hips back to generate tightness in the hips during the hinge movement.
Like I mentioned in my previous post, you can practice this by using RDLs to maintain upper body tightness while hinging and only using a ROM that allows you to keep a rigid torso. Your ROM and torso strength will increase over time to the point where you will feel strong in the start position when pulling from the floor. It might even be best to stick to only RDLs for a month or two instead of competition DLs to ingrain this technique and allow your mid back strength to catch up.