watch WMV video (70 KB)
watch RM video (34 KB)
A windmill overhead, more commonly called a sky hook overhead, should only be used in two circumstances:
- When you will be unable to meet the ball in front of yourself.
- When extreme wind or some other factor makes timing your overhead especially difficult.
As a general principle, the larger the radius of rotation in a tennis swing, the less precise your timing has to be. A swing that pivots at your wrist makes the angle of the racquet face change more quickly than one that pivots at your shoulder. A standard overhead is produced by a kinetic chain that translates leg and trunk energy into shoulder rotation, then faster elbow rotation, then very fast wrist rotation, all up and forward. A sky hook overhead is generated almost entirely by shoulder rotation, which makes its timing less critical.
With its greater forgiveness on point of contact and timing, the sky hook might seem a good candidate to replace the standard overhead altogether, but it has two disadvantages that make it clearly a second choice. Regularly swinging with a straight arm at overheads or serves is brutal to your shoulder, and you'll never generate nearly as much power as you can with the standard motion.
The next page details how to hit the sky hook overhead and contains links to the same video clips linked above.

