OK, I know sometimes I say things that really don’t make sense…but this isn’t one of those times.  As you learned in my last post, the muscle that feels like it’s your armpit, your Serratus Anterior, keeps your scapula (shoulder blade) attached to your ribcage, helps stabilize it, and helps the whole shoulder move properly.  Now, what does that have to do with your spine?

Let’s think about it in simple terms.

Your spine is attached to three major structures – your pelvis, ribcage, and head.

So, when any of those move, your spine moves.

And, your scapulae (yes, that’s the plural…) sit on the back of your ribcage.

And your ribcage is curved side-to-side and top-to-bottom.

So, when your scapulae move, they should glide around the surface of your ribcage in an appropriate range.  But, it’s not a big surface…there’s only so much space between your spine and the side of your body, and there’s only so much space they can travel up or down before they shift the position of your ribcage.

Try it:

  • Shrug your shoulders.  At some point, the scapulae start tipping the top of your ribcage forward which will round your back and “crane” your neck.
  • Then pull your shoulders down your back, and within a short range, they will start pushing the bottom of your ribcage forward making your “ribs pop”.  And this motion pulls your spine into a bit of a backbend and likely won’t feel good on your low back.
  • Now, squeeze your scapulae together, and again, your ribs “pop” when you hit their end range.
  • And, then widen your shoulder blades, and again, you’ll find yourself rounding your spine (and probably shrugging your shoulders again).

So, when I talked about the importance of the Serratus Anterior, it’s partially because it keeps your scapulae moving in a range that does not affect the position of the ribcage if that’s what your movement calls for.  And, if you should be moving the ribcage, it’s part of the system that controls the movement.

And remember, I said that when your pelvis, ribcage, or head move that your spine moves?

Here we’re talking about your ribcage moving, right?  So, we’re inherently talking about your spine moving as well.  And keeping your spine moving in appropriate and proper ways/ranges is a big part of spinal safety.

The nice thing, though, is that your body is designed to try to help keep your movement safe – there are mechanisms in place to help you move well.

In this case, your Serratus Anterior inserts on the front of your ribcage right where your external obliques originate.  And, your external obliques (working bilaterally) hold your ribcage in place – well, they pull it downward and toward your midline, which corrects the “rib pop”.

(photo from www.daviddarling.info)

So, when you use your Serratus Anterior to stabilize your scapulae, your external obliques take the cue from that and pull your ribcage down and together in the front to prevent you from “popping” your ribs which generally will hyper-extend and/or compress your lumbar spine.

That is how your armpits help keep your spine safe.

Our bodies are amazing, aren’t they?!?