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Ground Reaction Force (GRF)
Newton's third law states that for every action, there is an equal and opposite reaction. In golf, the ground is your only source of leverage.
1. Horizontal (Shear)
The side-to-side force that shifts pressure back and forth, establishing the low point of the arc.
2. Torque (Rotational)
Pushing the trail foot backward and lead foot forward to rapidly spin the pelvis.
3. Vertical
Pushing straight down into the ground (posting up) to generate upward lift and maximum clubhead speed.
Timing is Everything
Force alone isn't enough; it must peak at the correct time. Vertical force must peak around lead arm parallel in the downswing. If it peaks at impact, you've missed the window to transfer that energy to the clubhead.
Use our Tempo Calculator to ensure your kinematic sequence has time to develop.