You're just plain too loose throughout, not just your back. Take more time to pull your chest up and stop dropping your hips.
General info:
Age: 22
Height: 185cm (6ft)
BW: 90kg (198lbs)
Hello everyone,
I have finally made the move to register on these forums to seek your help with my deadlifts. When I lifted 125kg (275 lbs) for the first time, I did so with abysmal form and a horribly rounded back. So I decided to not push the weight any further without getting my form straight. Then, I did what was probably the worst thing possibly and simply quit deadlifting for several weeks, dropping in power cleans and chin-ups. Now my squat, which I do not have any form issues with, is way ahead at 142,5kg (315 lbs). Now that the exams are out of my head, I am ready to tackle my form again and finally stop not doing the program. You may find a recording of my latest working set at 120kg (264 lbs) below. I do have to apologize for the clothing and the fact that my head isn't directly visible in lockout position. I cannot go back any further at my facility and it turns out the lighting was too poor for the smartphone camera, so even with a little editing there's little contrast between my clothes, which are the lightest in color I have. I tried making up for that by stuffing my shirt into my shorts directly below my waistline, but I'm afraid that didn't really help. Should the video be too poor to criticize my form on, please tell me right ahead.
YouTube
The main problem I have with my deadlift is my inability to properly set my lower back in the starting position. I do not have any problems maintaining lumbar extension in squats, but my thighs seem to get in the way when trying to set my back in the deadlift. Following the advice in the books and videos, I tried to widen my stance a bit and point my toes outwards a little more which I think helps but doesn't quite get me there yet. So currently I'm at the widest I can stand while keeping my arms straight with my current grip width. I am using a 4" belt for the latest working sets and I feel that it helps with my lower back. At least it looks (and feels) way worse without it. Could anyone evaluate my back setup and give advice on how to improve? There's two other things I have noticed when I watched the video. First, for whatever reason I am looking up way too high which I normally don't and second I seem to lose upper back tightness too soon on the descent.
Looking forward to your advice!
You're just plain too loose throughout, not just your back. Take more time to pull your chest up and stop dropping your hips.
Jeff's advice is sound. You may want to get some long stockings to protect your legs.
Second to Jeff's comments about the hips being low and squeezing your chest up while maintaining hip height.
I also see that you're moving the bar forward when you bring your shins to the bar. This is a no-no. Drop the weight back to maybe 225 lbs., keep a more vertical shin angle, and keep the hips high. Squeeze the chest, tighten entire back, and push the floor away from you.