The top box in the stack is either a 36 or 42 inch plyo box.
If you have either one, please put them away.
In fact, unless you are training some great athletes, put your 30 inch box away too. I have dubbed the big plyo boxes “Idiot Boxes”.
Idiot boxes are jumped on by young men ( it is always young men) looking to show off. I have begun to refer to them as “skin donors”. I can tell you something for sure, If CSI showed up and dusted the high plyo boxes for DNA most of these boxes would test positive.
There was a time when my athletes and I were foolish just like everyone else and did these foolish exercises. After coaching a few “skin donors” I realized that what mattered was the movement of the center of mass, not the height of the box. I no longer own a 36” box but, own lots of 18's, 24's and a few 30's.
Our rule is simple. Jimmy Radcliffe said it best; “Jump and land from the same position."
This means that take off and landing should look identical. If you jump from a ½ squat, land in a half squat.
I could post a few videos but, don't want to get sued. Just Youtube “box jumps” if you want to see foolishness in action.
Remember, jump and land from the same position.
PS- now that soft plyo boxes are a thing I still thing high box jumps are an ego inflating waster of time.