Learning How to Stop

FM Alexander developed his technique around a demand. The demand was essentially, "Do Something!"
In his case it was the demand to get on stage and project his voice in an acting career. As his voice deteriorated, he learned that what was happening to him was the natural result of the conditions present, and those conditions were being created by HIM. So what do you do? Just change the conditions!
The difficulty here lies in the fact that those conditions have become an ingrained habit...and how do you change a habit? Just stop! The Nike commercial becomes a remedial education commercial with the addition of one word, "JUST DON'T DO IT!"
But then what is a person to do if you're not to do?
Alexander's key was that he stumbled onto the principle in vertebrate physiology called the primary control (his term). Simply, it is the fact that what happens in the head/neck relationship with the back determines how well things work for the rest of the body.
So when FM says "Stop," it means, "stop interfering with the right head/neck relationship."
Just one Alexander lesson can open your eyes to what he means there, but to get it fully, it's a good idea to have a few lessons.
It's not chiropractic, and it's not physical therapy, although it enhances the results in both of those fields. Just remember, the goal with Alexander technique is to help you retrain yourself to avoid habits that interfere with the best outcome.