Different camera angles give us different perspectives on what is happening for a tennis stroke. I like the side view on the forehand to show how the mass of the double bend lifts up and pushes through the ball as the hand and racket hold back. In is only from a front angle, however, that we see just how fully the arm and racket come ACROSS the body, with the finish ending WAY across your body.

With this full arc ACROSS your body, how do you hit through the ball? The torso rotation and the lifting arm are all you need to get enough of a push through the ball. The rest of your energy will be in lifting and turning the arm in a rainbow like path.

It is absolutely essential that you keep your wrist back as you drag through and up and across the ball in your wiper motion. I drew the red lines in the Somdev clip to show how the wrist holds back as the arm starts its rainbow path through the ball. Well after contact, the wrist is still holding back. This allows the MASS of the arm, from the shoulder to the hand, to come through the ball. And this is why the arc of the racket stays on the right side of the body so long. As the arm lifts up and across, the wrist and racket hold back.

A great exercise is to practice drawing this full rainbow in front of a mirror. Make sure your wrist stays back like Somdev's as you draw the rainbow. The wrist can relax well after contact, as Somdev's does. Finish with the arm all the way across the body, touching your chin to your shoulder.