Frederick Alexander came up with the Alexander Technique in the 1890s when he found that a loss of voice during public speeches was bothering him quite a bit. When he got down to the root of it, he discovered that the underlying lack of confidence was brought upon by dissonance between his vocal cords, his mouth, and his lungs. They weren't functioning as one.
To alleviate this effect, the Alexander Technique was born. By making corresponding body parts as one, any task could be performed better. Take something as simple as turning your head around. When you simply twist your neck, you are causing a dissonance between your torso and your head. Gradually this is what leads to aching necks and a tired mind later on as time progresses. So how do you counter this? Not turn your head at all?
It's simple. Instead of turning your head only, move your entire torso along that direction. Say, you're turning to the right. Do not twist your neck muscles that way, but instead, tilt your entire torso in that direction so that the upper body moves as a single unit, along with your head. This makes the simple task of moving your head more efficient and elegant, and prevents neck strains.
One of the most important functions of the Alexander technique is correcting what people of this generation are plagued with: bad posture. As little as slacking your back for an hour while you browse through your phone can throw your posture off completely. A bad posture decreases blood flow and constricts the flow of fresh oxygen into the lungs. Essentially it is worsening your physical condition. Furthermore, a slumped back usually indicates a lack if athleticism, and can make you look unattractive.
Common methods that people use to correct their posture is to jut their chest forward, as if that somehow neutralizes the backwards slump. It doesn't, and it usually doesn't make things any better. An incredulously jutted chest is bad posture too.
Once again, the Alexander Technique shines with its beacon of hope. It says, "Hey! How about, instead of jutting your chest forward, creating that awful dissonance between your head, chest and abdomen, you try putting your whole upper body in a single frame?"
The idea is to not treat the back like an individual body part, but a lower extension of your head and an upwards extension of your abdomen. Try putting your whole upper body in a correct posture. Your head chest and abdomen are on the same level and facing the same direction. There is no strain, no dissonance, just everything working efficiently in harmony.
If you're ever running, when you're about to press one foot on the ground, treat the entirety of the body, except the other leg, as one, and put all your load in that leg, and thrust yourself. Then the other leg, and so on it goes.
Little by little, changes brought on by the Alexander Technique can bring physical happiness into your life.
But wait! There's always a psychological side to things too!
If you're a student, you know how messy your schedule seems to be, if you even have one. You always seem to be striving for time to do one thing or the other, and that leaves you feeling emotionally exhausted. In such a case, try thinking of the whole day as one single unit, where one thing goes into this time slot and the other in that. By treating the whole day, or the whole week, or month, or year, as one, you're creating an internal schedule that doesn't contain any dissonance, and everything fits right where it should, like a jigsaw puzzle. Mental stress goes boom. Now you're doing things in an order that feels natural and not contrived, and consequently you have more mental energy to spare for other things.
The applications of the Alexander Technique are vast and varied. After all, Frederick Alexander himself ended up writing four books on the whole subject, constantly making developments along the way. So it is safe to assume that practicing the Alexander Technique is an ever-evolving process, where you'll discover something new for everyone. There is no right way to do things. Everyone has a different way of singing, for example. But the Alexander Technique will help you find the way that fits you best. You can learn more about this wonderful topic from the Internet. Or anywhere, really. The world, just like the technique itself, is full of ever-evolving ideas on what the technique means.