The breathing cycle is a beautiful and complex mechanism, which when used consciously in a natural way, gives us immense control over our phrasing, tone, pitch control and dynamics. Used unnaturally, problems arise such as shortness of breath, excessive nerves, hyper-ventilation while playing, fatigue and the numerous symptoms of those misuses in our playing; erratic phrases, out of tune pitch and strident or hollow tone.
Breathing correctly, or naturally, comes naturally, if you let it happen without unnecessary interference. (Inhibiting unnecessary interference is the engine which drives the Alexander Technique.) Unfortunately, most wind players have interfered with the beautiful and natural inborn cycles of breathing muscles in their attempts to improve it or master it.
The link below takes you to an animation of a child respirating. Children use themselves naturally for the most part, until they are instructed to do something another way, when the pernicious issue of self-consciousness comes into play, often causing misuse which may never be corrected.
I recommend watching this cyclical animation of breathing for numerous cycles, breathing along with it to experience your own breathing cycle.
To begin the demonstration, click "start", then, to get the animation going, click "next" several times to see each phase of breathing. After that it should continue automatically. Be sure to also click "show ribs", which shows the beautiful elasticity of the rib cage expanding up and out, and contracting down and in. Notice how the top of the lungs and rib cage expand just as much as the bottom.
An unfortunate limitation of this animation is that it doesn't shows the surrounding body moving along with the ribs and lungs.
Watching someone breathe naturally is really mesmerizing, as the torso expands and contracts, rises and falls, seemingly independent from the head and neck. The shoulders, resting on the rib cage, only rise and fall as a consequence of the rib cage doing so, not from their own effort. Novices learning to breath consciously often think the shoulders should "be raised" when breathing, which creates tension in the neck and distortion of the natural cycle.To create inhalation, the diaphragm contracts, pulling down, creating negative space in the lungs, which then pull in air. As the same time, the ribs moves up and out (excursion) at the 24 (12 on each side) joints of the ribs along the spine, with the aid of the External Intercostal Muscles. The ribs also expand (excurse) at the cartilage tissue connecting the ribs to the sternum. Some of the neck muscles also help with inhalation, namely the scalene muscles of the neck, which connect to the top ribs and help them raise on inhalation.
Do not confuse these neck muscles with the Trapezius, right near by. These are the muscles used when you shrug your shoulders. At times it seems helpful to use these shoulder muscles to pull a bigger breath, but these create more tension than inhalation.
On exhalation, the diaphragm is passive, the lungs are eager to spring back to their smaller shape, just as a balloon released pushes air out, and the ribs pull in and down with the aid of the Internal Intercostal Muscles. Under exertion or while speaking or laughing or singing or playing a wind instrument, various abdominal muscles are used to push the diaphragm up and the air.
These abdominal muscles are:
-Transverse - the main muscles that hold your body insides ... inside
-Rectus - this is the "six pack" area
-External oblique - the left and right side "twisting" muscles
-Internal oblique - inner muscles that counterpart the externals to help with twisting
Instead of attempting to describe exactly how these muscles are used, which is not only difficult to verbalize, but also nearly impossible to enact consciously, it is better to turn to the instinctual use of these muscles, as in speaking or laughing. when the subtle use of abdominal muscles is observed, they may be seen to contribute to smooth exhalation with a "group effort". Here again, the concept of "inhibition" so often mentioned in the Alexander Technique is critical. Observation of our "natural" patterns often creates other misuses and un-helpful effort.
One of the best analogies I have heard to date to indicate how the abdomen feels when properly supporting is from Robert Marcellus, who said it feels like there is a tire around your abdomen pushing in from all around. Nothing else should be involved, not your neck, not your back (except lower), not your legs, not your shoulders, not your jaw, not your tongue, not your throat.
An easy exercise to help observe our natural support abilities is to put your hands on the sides of your waist and say soft laughing "ha" sounds with a little gasp between each. Notice how the whole torso is involved without tensing. Now increase volume. Keep the "tire" image in your mind as you feel the various muscles around your abdomen work in tandem to exert the huffing "ha" sound.
I also had success with one student with the following exercise. From a standing position, release your knees as you bend at the waist. Put your forearms on your knees to support this stance as you relax your torso and back, letting your butt go out behind you as your head and back become parallel to the floor. Take slow deep breath, letting your butt relax away from your torso toward what ever is behind you, let's say the wall. As your ribs round out and to the side, your head and neck remain relaxed, which allows the spine to "gather". Let this expanding torso/gathering spine movement continue until you are gently full... then exhale, letting your a) butt continue relaxing away from you as your b) head moves the opposite way and your c) spine lengthens and your d) torso (combination abdomen and ribs) squeezes in. Your spine feels like a soft stretchy necklace of beads in the middle of a balloon. When the balloon expands around the springy bead necklace, the beads pull closer together. When the balloon contracts, the beads move farther apart.
The emphasis here is to notice the involvement of the butt area as it expands to accommodate the viscera being pushed down and out, and then how it becomes the "spring" point from which the team of abdominal muscles and rib muscles push the air up and out. After a few breaths like this, slowly begin to move to standing, letting your head come up and forward, keeping knees bent and butt moving away from your head. Keep awareness of the freedom of your butt!!
Enjoy breathing deeply! Don't over think it. Just remember, breathing naturally really does come naturally. You don't have to learn how to do it, just learn how to control it with out interfering with it.