Definitions / Block 2 — Event Sequence
Free Jump
The effort of the takeoff leg during a free takeoff. It creates the takeoff angle — a balance between friction energy lost in the leg and a takeoff angle too flat, delaying immediate rotation acceleration.
The free jump is the effort of the takeoff leg during a free takeoff. It happens during the free takeoff, not after it.
It is a consequence of the free takeoff: the jump can only be free if the athlete is not actively resisting the pole while the foot is on the ground.
Its purpose is twofold. First, to create an optimal takeoff angle, so that the vaulter’s weight and impulse transfer to the pole with minimal energy loss. Second, to end in the position from which rotation acceleration can begin immediately.
The optimal angle is not a constant. It varies from athlete to athlete, from condition to condition, and from jump to jump. Identifying it is a balance: too steep and energy is lost to friction in the leg and muscle; too flat and the rotation acceleration is delayed while the pole is overloaded.
Related
Free Takeoff · Rotation Acceleration · Takeoff Point · Pre-Jump
The diagnostic use of this term, and how it is applied in coaching, is in the member vault.