Look at the animation and graph above. See the four colored curves; they represent the turning speed of the hips, (red), and ribcage, (green), and the swing speed of the lead arm, (blue), and club, (brown), throughout the whole swing. The most interesting part is the downswing near the middle of the graph. Here you see each curve accelerate (go up) and decelerate (go down). In an efficient, world class swing, as this one is, you will see smooth, sequential acceleration and deceleration of each body part with each peaking higher and later than the previous one, with the club peaking last, exactly at impact. This is commonly known as “cracking the whip”.
The Kinematic Sequence can be used to analyze your swing and determine how efficient and powerful you are.