Casey's Blog


Mar 12, 2021

There are very few muscles I actually “treat” directly, but the sternocleidomastoid (SCM) is one of them.

The SCM has a direct relationship with some vital structures and impacts movement in a multitude of joints including the neck, shoulders and jaw. The SCM attaches to the manubrium of the sternum and the medial third of the clavicle and the mastoid process of the temporal bone and the lateral half of the superior nuchal line of the occiput. It’s innervated by cranial nerve XI, the spinal accessory nerve and gets sensory supply from C2 & C3 for proprioception.                                                 Image by Joe Muscolino 

Image by Joe Muscolino

The SCM does the following joint movements:

  • extends the head and upper neck

  • flexes the lower neck

  • laterally flexes the head and neck

  • contralaterally rotates the head and neck

  • elevates the sternum and clavicle

Each muscle has a common referral pain pattern, the SCM’s referral pattern is around the eye, cheek, jaw, teeth, forehead and lower part of the back of the head.

This essentially means, it contributes to everything wrong with your neck and plays a huge role in your headaches.

I have two questions though before I treat an SCM:

  1. Why is it all jacked up?

  2. How do I fix it so it doesn’t just come back?

Here are a few reasons the SCM could be going bananas:

  • it’s stuck to the underlying structures

  • the accessory nerve is compressed

  • you have shitty posture

  • you have shitty breathing

  • your lymphatic system is blocked (the bottom attachment at the throat is where your body’s fluid drain is)

  • you’re stressed out

  • you’ve been injured (whiplash, shoulder injuries, clavicular issues, etc.

  • your SCM is compensating for other structures, like your abdominal muscles (neck get sore when you do sit ups?)

  • the head and neck aren’t moving enough

  • the head and neck are moving too much

  • you had dental work, a sinus or ear infection, a concussion

Here are a few reasons why your SCM issues need to get resolved:

  • your carotid artery and jugular vein, the blood vessels to and from your brain, run right underneath it (also why you should see a professional)

  • your ear is right in front of it and tension can cause ear infections or ringing in the ears

  • your vagus nerve, that innervates you heart, lungs and almost every organ south of the diaphragm, and is the primary parasympathetic (chill out) nerve runs beneath it

  • it affects the flow of the lymphatic system, which is a primary filtration system

  • it affects the position of your head in relation to your neck, which affects how your spinal cord exits your skull

  • it affects the neck and how the nerves that affect your shoulders and arms exit the neck

  • the little bugger is giving your very clear grief in terms of headaches

Now get yourself a pair of balls, treat your own SCM and see a manual therapist to make sure all of those essential structures are moving to keep your head, neck and jaw healthy and pain free!