AeroVault wrote:agapit wrote:Pecs are the weakest link.
I must tell you that we did not measure the relative strength of the muscle groups that participate in the movement due to lack of funds and equipment available for pole vault research, however we have conducted an extensive empirical research that led us to believe that out of all muscle groups participating in the movement the pecs are the weakest link.
I believe I understand what the pecs are doing. Unlike the fly or dumbell press where your pecs pull your arms around the axis of your body, in the vault, your pecs pull along the axis.
Still, I think of the pecs as a strong muscle group and am curious what led you to believe they are the weakest link. Is it necessary for a vaulter be able to bring their hips to the horizontal bar from a dead hang with only their pecs? Without engaging the abs or hip flexors, the athlete's legs would be cantilevered considerably and would take a great deal of strength. That, which I've only seen in dedicated gymnasts (and then only rarely).
I am very rusty in anatomy, but the actions I describe goes something like this:
Initial Chest penetration: The top arm horizontally extends and laterally rotates backwards. The rear deltoid and lateral rotators are working concentrically and the pectorals, anterior deltoids and medial rotators are being stretched.
Recovery from Chest penetration: The arm horizontally flexes and medially rotates. This involves the pectorals, anterior deltoid and medial rotators working concentrically.
Moving the body from take-off to inverted position requires work of many different muscle groups. I do not know if at any time you can say that a particular muscle group is disengaged from the action. We are talking more about a dominant muscle group at any particular stage of the body rotation.
In simple terms my point is that muscles group involved in the rotation of the arm to shorten the distance between the top hand and the torso are much weaker than the muscle groups that participate in the puling action to, in the similar way, shorten the distance between the top hand and the torso. In addition the puling action is done over the shorter distance and therefore potentially quicker than rotation (so called rowing action).
You can ask here, why are you just focusing on the speeding up of the rotation of the body? Would it not put a vaulter in the position where this is done too quickly and the pole does not penetrate far enough because the center of gravity is rising too quickly (the main factor in the final clearance height)? I must say that to remedy this, the vaulter should attempt to perform this rotation/inversion with a straighter body therefore keeping the center of gravity on average lower for a longer time. In essence this vaulter would put more energy into rotation and control speed of the rotation automatically with the keeping the body as straight as to complete the pole penetration and bar clearance.
Will you be teaching any of your auto-corrective excercises at SRU this Summer? I really hope so!
