This is an excerpt from Tennis Drill Book-2nd Edition, The by Tina L. Hoskins-Burney & Lex Carrington.
Thrust Launch Serve Technique
To take the basic flat serve to new levels by adding powerful lower-body technique to the mix.
While tossing the ball and shifting body weight forward, players step up to the baseline with the back foot and launch up and into the ball with both legs together. This action helps generate a tremendously powerful serve.
Players take a position at the baseline or the service line center (T) and start from the natural service ready position. They mirror the steps of the flat serve but after transferring body weight forward, they simultaneously step up with the back foot while tossing the ball, place the back foot next to the lead foot, bend both knees, and launch up and out with the legs together. This sequence produces tremendous power from the lower body. Players strike the ball at the peak of the toss for net clearance and control, and then land on the lead foot. They complete the follow-through and recover.
The accuracy of the toss is especially important when adding fancy footwork to the serve. After players toss the ball, it essentially stays stationary, but the body will be moving all over the place. Players must therefore place the toss in the same location every time. They must practice tossing the ball at least as much as they practice serving the ball, if not more. A great way to learn how to hit up on the serve is by sitting or kneeling on the baseline or service line next to the center (T). This type of positioning forces a player to really extend the racket head up and into the ball before swinging out to the service-court area. Players who crave more pace and depth on the serve should try exhaling to help prevent a choked stroke and to smoothly accelerate up and through the ball.
Learn more about Tennis Drill Book, Second Edition.