Tilte

HOW GRF IS APPLIED TO THE SWING

Set up

  • Possibly more pressure on the left side, providing the opportunity to push off the left foot (shear force) to transfer the pressure to the right foot.

Top of backswing

  • An important point to note is the change of direction has already started by this point “top of backswing” is only a reference

  • COM has not move much

  • COP approx. 80% on the right foot (normally towards the heel)

  • A lightening of pressure under the left foot, mostly towards the heel.

Transition – Left arm parallel to the ground in the downswing

  • 80% Pressure transfers to the left side in 3 ways

-Fall to the left (Gravity)

-Shear forces off right foot moving the COM forward – This force will help both COP transfer, and rotation (understand this force in 3D)

-Pushing up from the left foot, as the left leg starts to straighten.

  • Maximum pressure on the left foot is reached at this point, up to 1/3 more than the players body weight (normally towards the front of the foot)

  • Often great players lose height in this stage (down to the left)

Impact

  • These forces will start pre-impact. Again we use the term “impact” as a approx. reference.

  • A pushing up and away from the target, counteracting the forces from the club. This may vary club to club, generally speaking a lot more with the driver.

  • Understand the direction of the shear force in 3D, and how it affects the COP and rotation speed.

GRF Drills