Originally Posted by Finster
Does having a vertical tossing arm automatically put you into the ideal trophy bow-shaped pose? One thing that is also hard to do is to be in that pose, up onto your toes which, if you're not used to it, will throw you off balance. Look at all pics of the pros -- they are on their toes, their arms straight up in the air, their bodies in this "cocked" bowed shape. Is this a pose that is doable for us mere mortals? The more I try to get up onto my toes like that, the more I feel I'm going to topple over.
One thing to remember in looking at still photos is that it is a mere few milliseconds in time. The trophy stage is still pretty fluid, unless your toss is so high you need to wait for it (which can cause a hitch and impair the easy flow of kinetic energy into the motion). You shouldn’t be in that pose long enough to have to hold it there.
Another thing to note in the photos you are seeing is the shift in the center of mass/gravity in the body, which starts on the front foot, shifts rearward and comes back to the front all in the same motion, in time with any leaning that is done. The rising to the toes is often proportional to (and compensates for) the degree of knee flexion to maintain balance, but also aids in release of kinetic energy.
I’ve found that taking the arm to vertical after release of the toss serves two purposes: one, it creates and maintains the shoulder tilt that allows for the forceful reversal in the shoulder over shoulder “tumble” that is part of a mechanically correct serve. If your shoulders are level, then the upper part of your racquet arm will need to elevate above the plane of the shoulders, which can lead to injury with force and repetition.
Second it helps create and maintain your stored kinetic energy for release. Raising your arm to vertical with your weight back will tend to force your hip forward to maintain balance, creating the “archer’s bow “ It also helps keep the trunk rotation and your hitting arm back a bit longer for a more forceful release. Dropping your tossing arm too soon invariably costs you your rotational energy, and many pros will tell you to leave it up as long as possible.