The greatest amount of power within a golf swing comes from the torque created within the body.
When loading up during the backswing it is essential to make the proper amount of shoulder turn - up to 90 degrees. If a 90 degree turn can be achieved then your back should be facing directly toward the target at the top of your swing. This creates power as the body is coiled up and then released through the downswing motion. Strong legs, back and abdominal muscles will help increase the strength of this uncoiling process.