As title says when i deadlift my hips always rise to quickly, and i end up doing a stiff leg deadlift. This only seems to happen when i go heavy or im fatigued, i did some reps with a lower weight and form was no longer an issue, my arse stayed down.
So i don;t think its an issue of flexibility or mobility (ive read all the articles on hip/glute activation) rather i think its a weakness such as weak glutes or hamstrings. I also fagely remember an article by jim wendler which suggested that hips rising to fast could be due to weak quads which help break the lift off the floor. Any thoughts? Are there any exercises you guys have found have helped with this problem?
Cheers guys
oh and here is a vid of my form (sorry about the angle) good bad?


