My Old Roommate ...and the Sternocleidomastoid Muscle.

This particular post is a shout-out to my awesome undergraduate roommate. I really miss him and wish that his daily activities were the background noise for my studying. I had pizza tonight and thought of his, Tony, and I's late-night pizza runs across the street (and I recall those trips to the $5 place across from our old apartment too). I want to wish my former roommate a great evening (but I'm sure he is having one because I know his favorite TV show is on tonight).

In Anatomy news...

Remember when you get drowsy and feel yourself "nodding off" while in class, reading a book, or watching a movie? Remember how funny it is to see someone else falling asleep in public, with their head sagging? You see their head tilt back and forth, and then eventually hang as they snooze. Well, the expression "nodding off" is appropriately named because when you start to drift into sleepy-land, your head starts to "nod" as it sags back and forth. When you do drift off, your head hangs as a result of the relaxation of the sternocleidomastoid (SCM) muscle. This muscle, which can be felt protruding slightly out, and on either side, of the neck, is responsible for holding the head in an upright position. Our head is not balanced on our neck properly; most of the weight of the skull is concentrated towards the back of the head. In order to keep our head balanced, the SCM muscle has to pull forward to keep the head upright. You are able to lift your head off the pillow in the morning due to the SCM muscle being "woken-up" and contracted. On the other hand, when you feel yourself falling asleep, the SCM muscle is relaxing too, hence the sagging, unbalanced head.


  1. Hey old roomie! Miss you too! Hope your studying is going well!

    A quick question: What is the best way to avoid relaxing this particular muscle?

    I find myself nodding off all the time, is there a specific way one should sit? I would like to stay awake when watching a movie or reading. Thanks!

  2. Well my SCM muscle relaxes alot in front of the TV!!!! - lol.

    This is so interesting because two of my housemates which aren't human,(animals lol) sleep with their heads upright so they must have a stronger or different muscle in their necks. Cool.

    BTW We all miss our former roomies too :(

    xoxoxoxo PJ & M

  3. Sorry, no way to prevent the muscle from relaxing. When it is relaxing, it means you are tired. So, the best thing to do would be to get some more sleep! It shouldn't relax in the middle of movie watching or reading... unless you are just too tired.


Thanks for your comment!