Both of these pictures show a maximal involvement of the posterior chain when squatting. The posterior chain is what drives the human body, it is the true core. It consists of the hamstrings, glutes, spinal erectors, and even to some extent the lats. If you want to improve performance this area of the body has to be strong and in sync. One way to maximize posterior chain strength is with box squats as pictured above. The main points here will be the use of a wider than usual stance with the toes slightly pointed outwards. From here, keep the chest high, elbows pulled back, knees pushed maximally outward, and sit the hips as far back as possible onto the box. Notice the perpendicular, almost past perpendicular, shins in relation to the floor. Once on the box, temporarily relax the hip flexors (keeping the lungs and lower abdomen full of air at all times) and then with all your might (like you would in the split jerk we practiced last night) contract forcefully by first pushing your traps into the bar followed by applying great force into the ground with the cue in your mind of the feet spreading the floor back into the standing position. I know that is a lot to think about but just read it again and picture each little thing in your mind. When you get here tonight will use that picture you have in your mind to help you perform elite box squats with a heavy load.

WOD
For Time
Box Squat
10-9-8-7-6-5-4-3-2-1 reps
Burpees
1-2-3-4-5-6-7-8-9-10 reps

Focus as though this was a max effort day and pick the heaviest load you can handle as the reps do drop thus making the exercise easier as the workout progresses. As for the burpees, YOU MAY NOT, I REPEAT, MAY NOT BREAK THE REPS UP. I don't care what you feel like inside, muster everything you have not to break the reps up. Can accept and follow through with this challenge?