Because of a flexible shaft and a heavy clubhead, both flung at a stationary ball at high speed, impact in golf does not lend itself to a simple description.
From the top of the backswing to impact about 1/5 of a second elapses. The accelerating, clubhead builds up a considerable amount of speed. It meets the ball with a force of almost 2,000 pounds and remains in contact with it for 0.0005 seconds. During that time, the clubhead travels from 3/4” to 1”.
The force of impact with a stationary object, the golf ball, immediately slows the clubhead down by about 25 percent.
Spin gets applied to the ball, about 3-4,000 RPM with a driver, and about four times that with a 9-iron.
The heavier clubhead was in front of the shaft near impact, giving the shaft a concave shape in relation to the target. The collision of the clubhead and the ball slows the clubhead down more than the shaft, so the shaft flips into a convex shape in relation to the target.
Centrifugal force built up at impact pulls on the player’s hands with a force of about 40 to 60 pounds.
The golfer feels the shock of impact, but not simultaneously with the event itself. The vibration takes 0.00067 seconds to travel up the shaft to the player’s hands. By this time the ball has already left the clubface. From there the nerve impulse takes 0.01 seconds to travel to the player’s brain, by which time the ball has separated from the clubhead by almost 12 inches. Were the player to react in some way to the feel of impact, by the time a correction could be applied, the ball would be almost fifteen yards down range.