The spine holds incredible secrets for singers. If you know how to say the magic word....
Actually, if you know how to bend the thing!
First of all, there's C-1, or cervical vertebrae one. That's the top of your spine, the bone upon which your skull hinges. If you bring that vertebrae back ever so slightly (without raising your chin), you can double the space at the back of your throat or vocal tract. Especially if you raise your eyebrows in an "I don't think so!" type of facial gesture. Try it... I bet you feel your nose flare.
Then there's the spot in your upper back just below your shoulder blades. You can open your whole ribcage by pressing this spot and moving it inwards. This gives your diaphragm room to hold back, or control, breath. Students of mine often get a hoola hoop lesson to help them literally loosen up so this spot becomes more flexible. According to my chiropractor, Dr. Dwaine Allison, http://www.allisonchiropractic.com , this spot is in fact the accupressure point for the diaphragm, and so affects nerve impulses to the diaphragm as well as physical space. I highly recommend this doctor, by the way.
And lastly there's the lumbar spine. Think of the diaphragm as having a mushroom-like shape. The outer edges are connected along the bottom of the ribcage. The "stem" has fibers that attach to the lower vertebrae of the spine, which sit above the tailbone. It's important to think of the lumbar spine as support. If you bend too much here (at the waist), such as in a sway-back stance, you can cause breathing problems (as well as back problems). Flexibility in unlocked knees will keep the lumbar in a better position to support the voice from the pelvic floor and still allow much needed flexibility in the upper mid-back, as described above.
Here is a site you may find interesting about anatomy and breath. Notice, however, that they are talking about regular breathing, not singing- which requires more control and thus a lifted and open ribcage during phonation. http://www.authentic-breathing.com/abdominal-breathing.htm
I try to visit my chiropractor before every major vocal. I found that a spinal alignment could make a significant difference when I needed maximum voice. Also, feel the dance in your spine, the beat in your legs, sway the groove with bent knees, etc. ...do what it takes to let flexibility into your spine. You might be surprised at how much this can help your vocal cords! (the hip-bone's connected to the jawbone... eventually!)
Do you have trouble with flexibility? What helps you loosen up? Click on "comment" below.