Place three fingers right at the tip-top of your sternum, just inside of where your collarbones end. Now, gently turn your head from side to side. When you feel your fingers move, you've found one of the points where your sterno-cleido-mastoid muscle (SCM) begins! The other is just a little bit farther out to the side, attached to the innermost third of your collarbone. It's a muscle that helps with rotation of the head, and also lowering the head, among other things. This tiny muscle is the HULK! Stick with me; knowing anatomy can help your practice, and can rock your sparring like a hurricane.
Why is this beautiful?
Life has created an incredible tool for itself!
The SCM is a muscle that:
- Connects to two different body parts
- The sternum, which holds your ribs together. That means the SCM is one of many muscles holding your rib cage in place so it doesn't tilt forward. Imagine what this means for big-chested people: the SCM connects at the back of the neck, the Emerald City gates of all neurological function. No wonder a breast reduction has serious beneficial implications on pain management.
- Changes direction
- Most major muscles have a "1 or 0" way of working. The simple bicep either contracts or it doesn't. The SCM is a muscle that everybody takes seriously. A little injury can cause a lot of trouble.
"And though she be but little, she is fierce."
-William Shakespeare, A Midsummer Night's Dream
- Facilitates movement in many directions
- Lateral rotation of the head (side to side)
- Turning to follow the opponent
- Rockin' your very best kata
- Flexion of the head (up and down)
- Bending your head down to protect your airway
- Lifts the rib cage
- The SCM does part of the work of lifting the rib cage up so that you can take a deep breath, the kind that goes to your abdomen and makes you feel really good.
- Sanchin Kata
- Tensho Kata
- Tai Otoshi (body drop)
It's interesting that we have large sheets of muscle on the tops of our skulls because those bones are fused. One would think it would be thick connective tissue, although there is plenty of that, too. From my inexperienced perspective, the explanation may include that the muscles of the skull help facilitate developmental fusion of skull segments in babies, or working connection with the facial and jaw muscles. I've got to be missing something, though.
When I was studying medicine I had a place for these ruminations to go. Since I won't likely become well enough to continue my studies, I'm grateful that karate provides an outlet for my thoughts on anatomy and physiology (A&P). Ehlers-Danlos Syndrome (EDS) is a giant anomaly of A&P, but because I live with it at all times it isn't the healthiest place to nest all my curiosities. The lens of having EDS also produces distortions and bias, whereas karate is practiced and studied by a diverse population, and provides for more well-rounded thinking.
This whole post is a little heady (*snicker*) for a Sunday morning, but still fascinating to think about!