Nick Faldo describes his sensations from the top of the backswing into the downswing and then impact. The sequence of movements that occur as you reach the top of the backswing into the start of the downswing is usually referred to as the transition. Ultimately every players transitional sequence will vary slightly but I think Nick Faldo does a great job in describing his feelings.
'' I liked to feel the left shoulder and left knee move away together and pull away from a resisting right side.'' He describes the movement as the moment of separation and states that ''it's crucial to unwind correctly.'' ''Once the weight has flowed back to the left the right shoulder, right hip and then right knee in that order can fire. If this separation is created at the beginning of the transition it gives the body room to rotate hard through impact. At the very last second the right shoulder, hip and knee fire through impact.''