Here is a fascinating video from Harvard University on the Mechanics of Throwing, along with the human history of throwing things.
Finally, a video on the biomechanics of kicking a ball:
Piano playing happens in much the same way. In fact, every musician should be doing the same thing. A conductor gives the pick-up to the first downbeat, thus preparing the entire orchestra for their entrance, giving them the tempo of the piece, and giving the musicians a chance to get their first notes prepared. Imagine a conductor starting with his/her hands raised and suddenly dropping them for the downbeat. The sound would be harsh, rushed, and not synchronized. Imagine a wind player would start without inhaling...actually that is impossible. Equally impossible would be a percussionist initiating a stroke without raising the mallet.
As pianists we must therefore think about these motions as well. I believe we think about depressing the keys far too much and not nearly enough about our motions AWAY from the keys, moving upwards and not downwards.
Why is this? For one it lies, I believe, in the nature of the instrument. The piano is in essence is a big hunk of furniture. We have little intimate connection with it. We don't caress it like string players do with their instruments and we surely don't put it in or on our mouths. How much more intimate can it get than with wind instruments? And so, piano players, especially young ones, find themselves concerned with "hitting" and depressing the keys. And for better or for worse, we can achieve a rather decent tone without concerning ourselves too much with these various directions of motion.
Another reason could lie in the fact that many pianists are not reliant upon other musicians. Therefore they do not have to rely upon starting together, breathing together, etc. All that matters, or so they think, is what is going on in their head. They know when the downbeat occurs and that is suffice. Unfortunately it is not.
Finally, much of what I am advocating involves motions away from the keys. And while I am not saying that we should lift our hands way off the keyboard, the thought of losing contact with the keys can be scary. However it does not have to be. But this fear keeps us from moving freely across our instruments, it keeps us stuck to the keys and it forces us to "push" from the keys, thus generating a lot of uncontrolled force into the keys. This in turn causes an unpredictable, uncontrolled, and often harsh sound.
In the next article, I will be demonstrating these athletic concepts as they should occur at the keyboard.