vault3rb0y wrote:willrieffer wrote:
I "blamed" myself, my lack of a coach, and time. And as much as you focus on the 'free take off' aspect, that still leaves the double leg, which I also experimented with and left behind.
Will
The exact same advice goes for the double leg swing as it does for the free take off. Countless reps in more controllable conditions are needed for it to be implemented in the vault. I just didn't specifically cite the double legged swing in my earlier post because I don't believe in training a double legged swing the same way I believe in training a free take off. BTB offers great commentary on the double leg swing, but I'll offer up why I don't train it for you, since I doubt you own a copy of BTB. If you don't, I would suggest getting a copy because even if you don't agree with all of it, it'll help you identify exactly WHAT you don't agree with, and it's the most comprehensive PV book ever written. But anyway...
1.) Technical reason: Time wasted. Most importantly, it takes time to drop the drive knee before beginning a double legged swing. The time between the pole making contact with the box and the start of the swing MUST be minimized, because any time spent on the pole that you are not actively converting energy from your muscles into the pole by a long and continuous inversion is WASTED time (a passive phase, as described by the 640m.com model of vaulting. Check that out, too! It's another amazing resource by Roman Botcharnikov). If a dropped knee and double leg swing adds more energy into the pole, it must MORE THAN make up for the energy lost by the addition of a longer passive time phase before inversion begins. I believe that it does not.
2.) Physiological reason: Less force production. A split position between the drive knee and trail leg increases the muscular stretch in the abdominal muscles and the hip flexors. This creates a stretch reflex that activates neurological muscle spindles, which automatically increase the force production of the muscle to protect it from injury from too much stretch. Also, a stretched muscle has an ideal length that it will produce it's maximal amount of force (This is the same reason your bicep is stronger when your elbow is at a higher angle when compared to a lower angle. This is yet a more complicated issue but I'll go into it if you like. *HINT* force = # of crossbridges formed). This allows the contraction of the muscle and inversion to happen sooner, and more forcefully, than if you drop the lead knee, which would take the stretch out of these hip flexor muscles. If a dropped knee and double leg swing adds more force to the pole, it most MORE THAN make up for the loss of force production that is created by a stronger stretch in the hip flexors. I believe it does not.
Now I realize that you said you experimented with the dropped knee and left it behind, and so you don't think the double leg swing is good after your experience. That's all good and well, but be careful not to assume that just because it gave you difficulty, that it must not be the ideal way to vault! I don't believe it is the ideal way, either. But my explanation is based on the reasons above, not on personal experience or distorted and over-complicated physics.
If you're going to dig into the deep and complicated elements of physics, biomechanics, and physiology to explain a model of the vault, you have a responsibility to do so clearly, simply, and in a way that is easily understood by the average PV'er or enthusiast reading it from their couch.
Well, even as I dropped, both, because I couldn't do them, I still look at both for possible advantages/disadvantages. The reason I could do neither, and dropped them, were all my own, and have nothing to do with whether I thought they were good or not. I get the information on them in the middle of a short track season with no coach, try them, and decided I didn't have time to relearn the vault with the season ending meet coming up. That's about it...