BOOMER, you need to think about your reasoning a bit more. Perhaps if you were jumping vertically off of a 45deg platform it would be simlar to rowing, NOT jumping off a surface that is perpendicular to the direction you are jumping, as with jumpies.
Anyway this passage is from "Steve Fairbairn on Rowing," pp.
437-438. The last sentence has some bearing on this discussion.
Summary of Body movement
The body movement in slow motions would show something like this: just as the oarsmen is arriving at the full reach forward, the weight comes off the slide and gathers on the stretcher, and the feet push the behind away, and somewhat upward, and so stretch the body, and hang the weight on to the lower part of the back. Really that is putting the whole back into it. Then as the draw couples with the drive, the top part of the body is driven right back with all the weight applied, and the body carries further past the perpendicular than it can with the back held straight. The thought should be: come down on the stretcher and stand on it. Imagine that at the movement of the catch the oar and boat got fixed immovably, and the seat disappeared, and one had to hang there. To do that he would have to keep pushing the behind away. So in rowing one should use the behind as a propelling weight.
The more one thinks of holding the back straight and getting the shoulders over, the heavier one sits on the seat, and the less one uses the legs. Drive your behind to hit the rowing pin and stand on it, and row standing up; do not row for showy form which is rowing sitting down. As regards the use of the feet I have frequently heard a discussion as to whether one used the heels and the ball of the foot, or only the ball of the foot. Think only of coming up on to the stretcher, and springing off it, and our old pal, the Subjective Mind, will do the rest; and as you spring think of pulling, or, shall we say, hauling or heaving at an invisible rope. To get a true heave the heels must be put into the work. I used to get good results from "drive your heels through the stretcher."
The only bit which causes some problems is that when people try to "lift their body" by hanging on the handle, they tend to do that by driving off the toes. And once you lift your body, you limit the horizontal force capacity based on your bodyweight, we really do need to stay on the seat.
