altius wrote:....., like Tim, I believe that vaulters MUST learn to use the left arm very precisely throughout the plant and into the take off. My observation of large numbers of young vaulters in the US over the last few years along with discussion with their coaches indicates that few really understand how the lower arm/wrist/hand should be used in this phase. I remember Petrov did an hour lecture on this topic at Reno a few years ago and I sensed that most of the audience were left bemused because what he was presenting was so different from their practice; in essence they did not understand why this very specific method was critical to the take off and swing into inversion.
I realised some time ago that I had not adequately clarified this issue in BTB because I had tended to take it for granted - should not have done so because it is very important.
Great topic - So lets have it....how should the bottom arm be used properly? I wasn't present for Petrov's lecture - I'm all ears I've heard/read advice like: "the top arm bends the pole, not the bottom arm", "its pole vaulting, not pole bending", "make space with the bottom arm", "arms go elastic", or "don't lock out the bottom arm - it kills with swing". None of these (other than the last one) are very specific instruction for the vaulter in what the role of the bottom arm should be in the plant and take-off phases of the vault. But without proper use of the bottom arm, the vault is doomed.
I've attached an example that I think shows improper use of the bottom arm. (Note: The top hand is about 7'10" or 2.39m above the runway at takeoff, and the grip height on the pole is 12'0" or 3.66m - so the pole angle is pretty steep to start with.) This vaulter is not using the bottom arm well, so his body swings from the top hand like a pendulum and is on his back too soon. I've also seen examples of too much bottom arm. or blocking, which is bad too. How do we coach this aspect (use of the bottom arm) of the plant & take-off?
Using this vaulter as a case study, how do we fix this? What drills will correct this? What should we tell a vaulter with this issue to focus on at plant & take-off so that the bottom arm is used correctly?
This vaulter goes to the other extreme - locking out the bottom arm at plant and take-off to get the pole to have a big bend. As you can start to see in the last frame, he has to break the lock on the bottom arm in order to swing his legs up. However, he also has to break at the hips as well and tuck because so much of his swing was blocked by his lower arm in the take-off & drive phases.
Likewise, with the bottom arm blockers - how do we fix this? What drills will correct this? What should we tell a vaulter with this issue to focus on at plant & take-off so that the bottom arm is used correctly?