High squat mobility, poor control. This is more common in females, but also in males who've played sports that demand extra mobility as a kid, or who have a lot of congenital joint laxity.
For these people, they need to focus on trying to control the movement more, which means slowing down and thinking about positioning and trying not to bounce through the movement.
How many Mondays have you been to the gym, anxiously awaiting your chest workout, only to find that you have to wait 45 minutes just to get on a bench? It seems that every guy in the gym trains his chest on Monday; it's a foregone conclusion.
We love the workouts that make you ache, the ones that make you shake your fist at the heavens above. This one involves doing one-rep maxes with 60-second negatives, followed by some nice drop sets.