The latest scientific studies between average golfers and skilled golfers show that there is a large discrepancy in the speed of the hips.
Good golfers are able to demonstrate much greater hip strength and power, which allows them to shift and turn more powerfully. This leads to higher clubhead speed, more distance, and generally lower scores.
Rory McIlroy is a great example of this. He has one of the fastest and most powerful hip movements on tour as measured by degrees per second. Watch:
The navel area, being the center of the body’s mass, is at the heart of the kinetic chain. The large muscles of the glutes, thighs, and hips cause the navel to move first to get the whole bullwhip action started.
When the hips can move fast, the torso responds by unwinding and carrying the arms around the arc with it automatically. The arms will simply feel relaxed and supple – reactive to the trunk and legs.