Yeah well in the past I was definitely a reactive jumper with all that it implies... I was jumping at an established speed with a long run-up at ~7-10 steps I suppose. All I was doing was pre-contract isometrically before my jumping leg was hitting the ground and then just extend at the hip...
I still do some of those things now but it's obviously a strength jump because jumping to a rim, that's higher than you and you need to "reach" towards it makes you become such a jumper.
i can't jump at all going a constant speed.. if i'm not accelerating into it, i can't jump.. i have been trying to do that though, working on it.. working on longer run ups too.. when i do longer runups i have a smaller penult, but my jump height suffers.. i just can't transfer it to vertical, i get much more horizontal..
You could try what I was suggesting to Nightfly (and what I'm going to do myself): a 5 step acceleration followed by like a 10 step constant speed and a submaximal jump over a low rope (high speed approach). You can also use a sprint into a submax jump. The idea is for the jump to occur at a constant speed so the muscles aren't forced to voluntarily create concentric power, just contract isometrically and absorb the shock.
In time you can get the rope higher as you get more efficient. One important thing to keep in mind though is that full hip hyperextension should occur (should be the focus of the jump) regardless of the jump height (well, that's important too but not as important as the hip extending properly).
