Take-off Mechanics

Speed conversion and the optimal angle

The take-off is the moment of truth where the parabolic trajectory of the jump is defined.

The objective is to convert the horizontal velocity of the run into vertical velocity, without losing too much progress.

Although theoretically a projectile reaches its maximum distance at 45 degrees, the human body, due to entry velocity and biomechanics, optimally takes off at a much lower angle, between 18 and 22 degrees (or 20-25 depending on the source).

Attempting to jump too high slows the athlete down; jumping too low shortens the flight.

The takeoff should feel like running "out and up," using the leverage created by the forward leg to catapult the hips into the air

The locking action and stiffness.

For energy conversion to be efficient, the swing leg must act like a stiff spring, not a soft shock absorber.

Upon impact with the board, the knee should flex as little as possible (minimizing knee flexion).

If the knee gives way and bends excessively (damping), the energy is dissipated in the muscles and the athlete sinks, losing the rebound effect.

The jumper must attack the board with an active downward and backward "clawing" action, creating instant ankle, knee and hip stiffness.

This stiffness allows the use of the elastic energy stored in the tendons (Achilles and patellar) to be repelled from the ground explosively in less than 0.2 seconds, insufficient time for a full voluntary muscle contraction.

Full extension and the use of free segments

As the swing leg locks and extends, the free segments (arms and free leg) play a vital role in generating vertical momentum.

The knee of the free leg should be aggressively driven upward until the thigh is parallel to the ground, locking in that position. Simultaneously, the opposite arm is forcefully raised.

This coordinated upward "drive" action helps to raise the center of mass and reduces the load on the swing leg.

The take-off ends with a full "triple extension" of the supporting leg, while the torso remains upright and neutral.