Changed the weight increases, sets and reps. Previously was training 60kg x 2, then going straight into 75kg x 1, and depth on this was a struggle. Due to my back injury, Birds and I came to the conclusion that I need to have smaller weight increases, so my back feels comfortable with the heavy load. So now after the 60kg x 2, we've been training sets of 65, 67.5 and 70kg and I'm able to do the 75kg much more comfortably, even after way more sets and reps. In fact, last session I squatted 75kg twice, and built up to it by doing 2 reps of 65, 67.5, 70 and 72.5kg