Well yeah but how do you translate the need for someone to plantar flex everytime they jump?
For example when I try to do consecutive vertical jumps of any kind (to the rim, backboard, over hurdles), I suck so bad at them because I ALWAYS land in a plantar flexed foot position after my first jump and I NEVER recover back. So I basically jump, land in a plantar flexed position, have to stop and reset, jump, land in a plantar flexed position, reset etc.
And it's terrible.
Can you post a video?
You are talking about a bunch of things that are pretty different. I was referring to single leg bounds, triple-jump second phase, etc. In all of these you have both horizontal speed and the other half of your body to propel you up and must learn with practice to attack the ground with the landing foot which itself will result in dorsi flexion. Because horizontal speed is so great you it will essentially suck otherwise. You can learn simply by practicing standing still. Stand on your left foot and jump up, kick your butt and accelerate the left leg to the ground. Repeat. Now start chaining them together. It might take awhile but I have seen pretty uncoordinated people pick it up this way eventually.
Now, double leg bounding (over hurdles or not) is a bit different because you have much less horizontal speed. It's also a little foreign for some people to accelerate their legs down together in a double leg bound. But again it's a learned skill. You plantar flex when you land because you jump too far. You can initially start with double legged bounding with your knees locked... all power comes from ankles, arms, a little hip pop. Should be easy to plantar flex throughout the duration of the rep. You can then move to bounds where you keep the distance short so that you can get your dorsi-flexion before landing. It really starts with the whole body... Which is why I hate the emphasis on plantar vs dorsi flexion. If you watch my double legs bounds at 35 seconds in the video (
http://www.youtube.com/watch?v=ImXLBmzCRXg&list=TLmaiQP-GpCJLcMA1CmMXJ9B3X8cX2GQ62 ) you will notice that in slow motion when I am descending I load my arms and legs up completely.... Focus on preparing for the next jump while you are still falling, not whether your toes are flexed or pointed... If you prepare for the jump in the air you will naturally flex your toes....
Finally... Consecutive vertical jumps are a very different beast all together. Consecutive vertical jumps don't have any horizontal speed to attack the ground with! Additionally if you are jumping just vertically you can't really attack the ground because your feet are already below your hips. Remember "attacking the ground" isn't really getting your foot to the ground faster... That is impossible, once you are airborne you are pulled down by gravity and can't get down any faster, what you can do is move one or both legs in front of your body and accelerate at the hip to swing it under the center of mass....
Thus, If you are trying to achieve short ground contacts on consecutive vertical jumps you will actually land on your toes and your heels will never hit the ground. If you try to accelerate the hips downward and dorsi-flex you will then fly forward instead of just up on the next jump. I could be wrong (would LOVE to see a counter-example) but I don't think there exists anybody who is actually so reactive that they can build up height with multiple full effort vertical jumps on a hard surface.... The ground forces from that height that you have to absorb are just too brutal... IMO if you could absorb the force you would be strong enough that you could have jumped higher than that! This is my experience with depth jumps for sure... I can get higher than my vertical with small boxes 12'', 24'', etc. But once I try to use boxes that approach my max jump it get's pretty difficult. Of course a depth drop to jump is much different from a max jump because you don't have to cycle through from extension back to flexion...
