If you’re jumping on tall boxes to be better at jumping on tall boxes, keep doing what you’re doing and enjoy being a skin donor from time to time.
If you’re jumping on boxes to improve athletic performance, you should follow these simple tips.
1) What matters most is the movement of the center of mass, not the height of the box. All you’ll need is a few 18, 24, and MAYBE 30 inch boxes.
2) The 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.
3) If you’re jumping to a very high box, all you’re really doing is testing how fast you can lift your feet up (hip flexion). The point of a box jump is to test explosive hip extension. Your knees should be only SLIGHTLY bent upon landing.
Know what you’re actually accomplishing when jumping to a box.
Easy as that.