with contributions by Keith Wittenstein. Special thanks to Sarah Court, Dinneen Viggiano and Trina Altman for editing and feedback
This article is Part 3 in a series on shoulder biomechanics.
Last time, I discussed the dissonance between scapuloclaviculohumeral rhythm and the common cue of scapular depression during shoulder flexion.
Instead of attempting to draw the shoulders down while simultaneously trying to flex the shoulders, consider ways to work and cue upward rotation of the scapula. A cue such as “Lift your outer shoulder blade up as you move your inner shoulder blade down” will facilitate more ease of movement and a safer position for the soft tissues of the shoulder Admittedly, this cue is far more nuanced than cues that take the whole shoulder blade in one direction, like “pull your shoulder blade down” or “lift your shoulder blade up”. However, if taught verbally – but then also reinforced tactilely by feeling the shoulder blade and its different angles and borders, and visually by seeing the shoulder blade upwardly rotate in a demonstration – can work to help students find and engage the muscles that upwardly rotate their shoulder blades to gain better command of this movement. Upward rotation makes it so the shoulder blade can push the humerus into the overhead position via its connection to the socket, or glenoid fossa. More on the scapula as a ‘pusher’ of the humerus rather than a ‘puller’ later!
The last need-to-know shoulder joint player is the scapulothoracic joint. It functions as the slide and glide interface between the scapula and the rib cage. It is the interface at which the scapula can do its action of upward rotation, or spin like a turntable, when the arm goes overhead. This joint is purely functional in that it does not have a joint capsule surrounding the articulating surfaces of its bones, as opposed to the other joints listed above. However, many powerful muscles act on this joint making it a biomechanical nexus of shoulder mobility and stability. We will explore one of these muscles in detail in later blog posts.
If it weren’t for all of these joints, the AC joint, the SC joint and the scapulothoracic joint, the humerus would move a measly 30-60 degrees forward or out to the side from the glenohumeral joint alone – that’s well below shoulder level – before coming to a screeching halt. This is because its glenoid fossa (that’s the shoulder socket) would not be able to progress into the upward-facing position that it needs to be in to continue cupping the spherical head of the humerus in the overhead position.
In other words, the humerus would have to dislocate to continue its trajectory upward (not a humorous thought)! Luckily this extreme example is really only to help you visualize the function of upward rotation of the scapula, and not something that actually happens thanks to the exquisitely designed co-movement between the scapula, clavicle and humerus. This co-movement is probably best described by the term scapuloclaviculohumeral rhythm (say that ten times really fast!), coined by the anatomist Joseph Muscolino. This term is not only fun to say, but also helpful to understand shoulder movement by reminding us that there are three bones involved in shoulder movement, the scapula, the clavicle and the humerus. The following video illustrates this co-movement and refers to the movement as ‘shoulder kinematics’.
In the video, notice specifically how, along with flexion of the humerus (upward reach of the arm), the AC joint – where the clavicle and scapula connect – must also move upward toward the head. Specifically this co-movement, or rhythm of clavicular elevation and scapular upward rotation is what permits the humerus to move overhead. Quite plainly, you’re best to go with this rhythm, not against it.
Now, you feel the beat!
Feel your own rhythm by placing your right hand’s middle and index fingers on the end of your left collar bone. Press down and rub around a little on the end of your collar bone and you might feel a Frankenstein-type bump. That’s where your collar bone articulates at the AC joint. Now raise your arm overhead. The end of your collarbone, or your AC joint, lifts upward along with your arm. That is the result elevation of our collarbone and upward rotation of your shoulder blade.
Keep tuning in this month for the rest of this series, Uplifting News for Depressed Shoulders!
Enjoyed this article? Read Reset Your Shoulders with Yoga Tune Up Therapy Balls.
The video that accompanies this blog is amazing and so helpful! Your clear description, along with the visual, really helped this lesson come alive. Thank you; I get it!!
This series is fantastic! Your description along with the video has allowed me to really wrap my head around the position of each of the joints throughout the full range of motion of the shoulder. Thanks!
Hear, hear! First of all, your writing is all at once clear, accurate and precise while also being very funny, which makes it super accessible to the average reader. This is an easy feat given the complexity of the joint you are writing about. You have also painted a really clear image about what exactly the risk is at the AC joint for those students overdoing the shoulder blade depression in shoulder flexion and how it just doesn’t make any good biomechanic sense to keep doing this. The video you linked to provides an awesome visual and I loved the… Read more »
Thanks for sharing the italicized paragraph at the bottom – that will help me with my wording for my clients. Video was a great visual too!
Love your humorous narration style (or humerus? You got me all confused now). The video is brilliant. Palpation suggestions are always a good idea in a class, they allow students to explore their so familiar and so infinitely intricate bodies.
New found respect for the shoulder joints. TO think of how much happens in that tiny area is fascinating and fills me with sheer amazement at human creation. I particularly like the palpation on the student allowing the inner lining of the scapula to move down and the outer lining to rotate upward. This makes it clearer. The video of course ties it all in together and the difference is quite obvious in the important of the upward rotation of the scapula to allow for a greater movement in the humerous and the joint overall.
Thanks for so clearly explaining the bone placement in shoulder flexion and how unhealthy a cue to “drop your shoulders” is. I also appreciate the video included – really helps visualize what you’re describing.
Thank you for another great article describing the relationship between these three bones of the shoulder girdle. The video is awesome- such a great visual aid. I also like that you included a tactile, self study practice so that I could immediately feel my own scapuloclaviculohumeral rhythm!
Then why do teachers from so many disciplines cue to lower the scapula when in shoulder flexion? Is it because they are not aware of this co-movement orchestration taking place? Knowing that this rhythm exists is changing the way I execute this motion and it makes me feel more invested in the quality of conscious effort I give to a movement that up until now, I did without paying much attention to.
OMG Yes!!! Thanks you for making this distinction. Where were your 10 years ago when I too enthusiastically followed the advice of a well-meaning pilates teacher to “get my shoulders out of my ears”? That, combined with a rotator cuff tear that made me afraid to push anything overhead, left me with chronically depressed shoulders. For the last few years, I’ve been trying to “fix” them by doing shrugs etc. to strengthen them in elevation, but still locking them down reflexively during normal abduction. Reading your post was exactly the “dope slap” I needed! Despite knowing the anatomy, I’d never… Read more »
The video was a great visual complement to your already clear and accessible explanation. I am wondering if you can share what additional cue you might give to a student who doesn’t have the body awareness to differentiate between inner and outer shoulder blades, and to someone whose tendency is to just hike the shoulders up with unnecessary muscular tension (in a group class setting where it may not be possible to demo or to give tactile hands-on feedback to all).
The video was a nice complement to your already clear and accessible explanation. Thank you for sharing. I love your cue, and wondering if you can share what additional cue you might give a student who doesn’t have the body awareness to differentiate between inner and outer shoulder blades, and to someone whose tendency is to just pull the shoulders up with unnecessary muscular tension (in a group class setting where it may not be possible to demo or to give tactile hands-on feedback to all). You may cover this in your future blogs in this series, which I am… Read more »
The video was a nice complement to your already clear and accessible explanation of the movements involved in the overhead arm position. And thank you for sharing your great cue. I would love to hear what additional cue you might give to a student who may not have the body awareness to differentiate between inner and outer shoulder blades and to someone whose tendency is to just to hike the shoulders up to the ears with unnecessary muscular tension (in a group class setting where you can’t stop and demo or give hands-on tactile feedback to all). You may cover… Read more »
This is great stuff Laurel. The video was excellent in its detail of how much each element contributes to the journey upward to shoulder flexion. It’s really amazing how many things have to coordinate for this rhythm to be smooth. I liked the embodied play with the distal end of the collarbone. That helped me start to really feel the difference between my “good” shoulder and the not so cooperating shoulder. Now if I could just teach the challenged shoulder a better sense of rhythm. Maybe one day!
Wow. Finally I have a visual of the scapulohumeral rhythm. Gobsmacked.
I love the suggestion of cuing upward rotation of the scapula! Playing with this direction in my own body, I feel so much more ease of movement, verses the general instruction of lifting & lower the shoulders in a more linear approach.
I definitely need to connect more with the muscles of my shoulder girdle. I admit, attempting to lift my outer shoulder blade up as I move my inner shoulder blade down, is not computing, but I am working on it. I found the video very informative. It is hard for me to visualize the actions, it took seeing the video to understand that the clavicle is moving too! It still blows my mind because when I am touching my own clavicle I don’t feel that movement.
Great little video! It’s been such an embodied epiphany to find natural scapular movement, not only in yoga asana and exercise, but in all aspects of day to day life. It’s amazing how many students (and musicians) think that shoulder blades just sit there!
I love the scapula spining upward like a turn table.
– Scapuloclaviculohumeral rythm – Scapula, clavicle and humerous – hey, I might try saying it in class someday 🙂
Reading your posts as I go.. this is all starting to make sense now. Total newbie at this stuff. You are very informative! Thank you!
Marin! Yes, protraction of the shoulder blades is a coupled action of external rotation of the arms while the arms are in flexion – SUPER improtant direction of movement that I did not dive deeply into in this post. The shoulder girdle complex is quite complex, isn’t it? As the arms go overhead, the shoulder blades glide in protraction, along a horizontal trajectory. In addition, they spin, like a turn table in upward rotation. Their lateral borders spin to face superiorly and their medial borders spin to face inferiorly.
Unfortunately, I read this series out of order. Now Part 4 makes a lot more sense. 🙂 This information is so helpful, and I will begin to introduce the cue you suggest at the beginning of the post. The video really helps, too.
I absolutely loved this post, especially the video – it’s such a clear explanation of how the joint is designed to work and how the common “melt your shoulders down your back” cue in yoga simply goes against nature. In watching the video and testing out my own shoulder flexion, I found that, by consciously moving the lower part of my scapula out away from my spine, I was able to achieve full flexion without pain!
I like: “Wrap the shoulder blades around the sides of your body.” Promotes safe, strong external rotation of the arms and engaging the serratus.
Love this series! YTU blog is the only one I read!
Very informative. Love the cue, for more direction. I often say lift, roll acknowledge squeeze. Now I will try yours