There is nothing wrong with your back position in this deadlift. Your hips are a too low/knees too forward/bar forward of the mid-foot, thus the huge curve in the bar path off the floor. But your low back remains in extension.
Youtube
I have a big issue deadlifting, in the video it is clear that my back gets the opposite shape that the normal one: low back shoots out becoming one single curve with the glutes while the upper part stays pefectly straight. And I really feel it while pulling, I feel that no matter how much i try to focus the stress on glutes, quads and hams the only part I feel working is the low back, which in fact also gets a pump at the end of each set. Is it only a hamstring strenght problem, so that I will maintain my low back straight if i can get them to be strong enough? I am really at a dead end having tried various methods.
There is nothing wrong with your back position in this deadlift. Your hips are a too low/knees too forward/bar forward of the mid-foot, thus the huge curve in the bar path off the floor. But your low back remains in extension.
Thanks for the reply, so how can i address the intense fatigue in the lumbar region during sets?
Get stronger.