Upper back collapsing in front squat
I'm pretty new to olympic lifting and have been having trouble with my front squat. My upper back is failing before my quads. On heavy sets of 3 I can usually do the first rep or two, but my upper back will collapse on the drive after that. However, once I had someone spot me, and all they had to do was slightly push my elbows up on the drive, and I could easily front squat the weight that I was just struggling with.
Is this a sign of a weak upper back? Weak core? Both? Is there any specific assistance work that will help this? Or is just more front squatting the answer.