Turn the Key, or How to Optimize Your Shoulder Alignment

When talking about shoulder alignment in yoga classes, the practitioner most often hears about the upper arm bone (the humerus) and the shoulder blade (the scapula). It usually involves some kind of language which instructs the practitioner to take the arm bone in the back plane of the body with the aim of positioning/keeping/securing the shoulder blade onto the back, that is, it deals with movement/articulation in the glenohumeral, or shoulder, joint, the place where the upper arm bone and the shoulder blade meet. This is true regardless of whether you weight bear directly on your hands or "just" have to keep your arms up or out to the side for example. This is true irrespective of the type of pose: forward bend, backbend, twist, arm balance, etc. If the shoulder blade is not optimally positioned on your back, then something above or below it will take the brunt such as your neck and head, elbow, hand, upper spine, ribs, even hips and sacrum. Optimal position of the scapula is beyond the scope of this post and I will leave that to the expert voice of Tom Myers.

What I want to draw attention to is the other shoulder bone, the collarbone (or clavicle), which forms the other shoulder joint or the acromioclavicular (AC) joint, which is the junction between the clavicle and the acromion of the scapula. If this already sounds like gibberish, here is a visual:

Shoulder from http://orthoinfo.aaos.org/topic.cfm?topic=A00394

The collarbones are largely forgotten in yoga class, besides the occasional instruction to broaden them during centering. In my experience, they are key to shoulder alignment. And I use the word "key" on purpose. Because the etymological root of clavicle means "key." It comes from the Latin clavicula, meaning small key or bolt. Doug Keller first drew my attention to this connection, and although I was impressed, it took a bit of time for me to make further connections. The same etymology goes across languages: ключица (klyuchitsa) in Bulgarian, meaning key bone; Schlüsselbein in German, meaning key bone; etc. This is also where clé or clef (key) come from in French. So, knowing the etymology was the first step to greater understanding. On an intellectual level, I understood that somehow the AC joint was instrumental in optimizing shoulder alignment, and the clavicle was like the key in the lock that unlocks that potential. This also made me remember the "broaden the collarbones" instruction  and practice it in a variety of poses.

Then, a couple of weeks ago, I was in yoga class doing jathara parivartanasana, let's say, taking my legs to the right, trying to will my left outer shoulder blade to stay on the floor, when I heard the teacher say, "Broaden from the right collarbone through the left collarbone," and it just worked like a beauty. Bringing my awareness to the collarbones brought about easier and more refined alignment to the arm bone-shoulder blade complex:

Jathara parivartanasana: revolved abdomen pose, from http://home.comcast.net/~raoulsch/bwy/bwy_prac.htm

Needless to say, I remembered all that Doug Keller had said about the "key" bone and went about exploring enthusiastically in my practice. The following muscles attach to the clavicle: trapezium, deltoid, the SCM, the pec major, the subclavius, and the sternoclavicular (or sternohyoid) plus a couple of ligaments. This would make the clavicle a key bony station in at least 3 of the 4 arm lines (see Myers above) as well as the deep front line via the sternohyoid.

To be clear, I am not saying to ignore the arm bone-scapula (shoulder) joint. This is the joint that primarily determines shoulder positioning and alignment. But I do think that the clavicle and its articulation at the AC joint with the shoulder blade is nothing to sneeze at if you are seeking refinement and more optimal shoulder alignment in your practice. As Wikipedia says about the AC joint: "The AC joint allows the ability to raise the arm above the head. This joint functions as a pivot point (although technically it is a gliding synovial joint), acting like a strut to help with movement of the scapula resulting in a greater degree of arm rotation."

So, in practice, what has helped me is to think of absorbing the distal edges of my clavicles into the body, in essence articulating my AC joint, plugging the key into the lock and turning it, so that I can then open wide the door of the shoulder (arm bone-shoulder blade) joint. Like a waving lucky cat when its paw is raised and facing forward. Doing that lucky cat wave (with the elbow bent) and having the fingertips of your other hand on your clavicle will show you what I am talking about (try having the fingertips at different points of the clavicle, starting from the center, closest to the sternum and then moving out towards the shoulder blade to get a sense of how the clavicle is indeed like a key that turns into a lock). So, when you bring your awareness to the clavicle and articulate at the AC joint, you are creating the conditions for the top chest to spread, lift, and broaden and for the shallow shoulder joint to express the mobility that it is known for (at least in theory). Think about absorbing the edges of your collarbones into the body next time you do pincha mayurasana (forearm stand) or set up for urdhva dhanurasana (wheel) and see how it goes and whether it helps you with moving your shoulder blades more fully onto your back. Then, start turning the key in other poses as well and see what doors it opens for you.