When I do reps, towards lockout it turns slow. Other than that how can I improve my deadlift form and technique?
Your thighs and feet are not in line.
Your pulling with the bar out in front. Sit back further. If your shins get too bloody, wear hgh socks.
Stop dropping the bar between reps. Descend slowly, briefly pause at the floor and pull maintaining the same position every rep. Doing this will build the glutes, hamstrings, adductors, and quads.
Throw the chuck taylors in the garbage. They are too squishy. Get some wrestling shoes, gymnastic slippers, chinese "kung fu slippers, or water shoes.
Grip the bar low in the fingers and when initiating the pull let the shoulder blades hang as low as possible. This raises the back angle and shortens the pull.
Finally, the secret weapon taught to me by Steve Scialpi, who at the time I trained under him, was one of only 4 198’s who had done 4x bodyweight. Load the bar with 35 lb plates, and perform high reps (40-50 reps over 4-5 sets) without touching the floor. Begin with 50% of your 1RM and add 5 lbs a week over 8 weeks. Lower the bar as close as possible to the floor without touching. After the 8 weeks are done, go back to 45 lb plates for three to four weeks, ramp the weight up and watch the PR’s fall.
The only thing i would suggest is at the top concentrate more on squeezing your glutes and driving your hips forward. Should help with the funky knees locking and hitch thing you got going on. Otherwise, looks fine.
You’re at the end of what you can do for reps with 375 with decent form. Don’t overcomplicate it.
Control the weight better on the eccentric. Lower it under control. Use a lighter weight and lower it under control to just below the knee then pull it back up again. Do reps like that. If you’re gonna drop the weight the way you are, just do singles. Block pulls can also help with doing reps.
To your point 6.) is this done like in a normal deadlift or more stiff leg ?
Exactly the same position as the sumo. Do NOT stiff leg these. My recommendation is to perfect your technique off the floor first under the eye of a sumo master. Seek one out and go train with them. Your technique needs to be dialed in before doing this because you will be doing so many reps that if your technique is not on, you will end up reinforcing bad movement patterns.
Thank you for response.