Why Your Shoulders Pinch During Shoulder CARs
A common experience when somebody first starts Kinstretch is experiencing pinching in their joints.
Most commonly we see this show up in the hips and in the shoulders.
We've already covered pinching in the hips (here), so today we're covering the shoulders — helping you understand what can cause pinching in your shoulders when doing exercise in general, or when doing exercises like shoulder CARs (controlled articular rotations).
Many people know that when they experience pinching in a shoulder CAR, it's not a normal finding. However, many people don't understand what is actually going on in the joint or what they need to do about it.
So let's deep dive into it.
What Causes Shoulder Pinching During Shoulder CARs?
When you're doing shoulder controlled articular rotations and you experience pinching — especially in an overhead position or when you are lifting your arm — this can be caused for various different reasons.
The most commonly discussed reason you'll find when you search for this is shoulder impingement.
But most people still don't know what shoulder impingement means, what causes it, or what to do about it after they get that answer. So let's go another layer deeper and help you understand shoulder impingement and how it can contribute to pinching during CARs.
Understanding Shoulder Impingement
There are a few different kinds of shoulder impingement, but the version most relevant here is subacromial shoulder impingement — impingement in the subacromial space at the front of the shoulder.
There is also internal shoulder impingement, which presents a little differently and generally causes pinching in the back of the shoulder rather than the front.
You don't need to understand all the anatomy behind those terms.
What you do need to understand is that subacromial impingement means we are running out of space in the front of the shoulder, and structures that shouldn't be getting pinched or compressed are getting pinched or compressed.
Something worth knowing is that it frequently doesn't start as pain — it starts as compression. This is often reported as “compression”, or even mild “congestion”, in the front of the shoulder when lifting their arm or working through a shoulder CAR in the overhead position.
It doesn't necessarily hurt, but there's a noticeable sensation of things being congested in that area.
Because it doesn't hurt, people assume it's fine (or good) to push through.
As someone who regularly sees people walk into my office after doing exactly that for extended periods, I would strongly advise against it as it can make things worse over time. Instead, we need to work around those range of motion.
I modify what many people call the closing angle pain rule to the closing angle sensation rule — I've included a video here that walks you through the difference in detail.
The short version is this: compression or congestion in a closing angle, even without pain, means we are likely experiencing contact where we shouldn't be, or dealing with abnormal joint function.
Pushing through it typically doesn't fix the underlying cause — it makes it worse — and this is often what eventually leads to actual pinching and unfavorable changes in our anatomy.
What Causes the Loss of Space in the Shoulder?
Once we understand that we're running out of space, the next question is why.
A number of different things can drive this.
Structural issues like bursitis and thickened tendons can take up more space and therefore contribute to pinching, but these rarely happen randomly or in isolation.
There's usually something else going on underneath them that has caused those structures to change over time.
Posterior Capsule Tightness
One of the most common underlying causes is posterior capsule tightness. Your shoulder capsule is a large connective tissue structure that holds your ball-and-socket joint together. When it gets tight — particularly in the back — it can drive impingement in the front of the shoulder, and cause compression of the rotator cuff tendon, biceps tendon, and the bursa.
This is how posterior capsule tightness leads to things like tendonitis and bursitis, which can themselves contribute to pinching on top of everything else.
When we look at an ultrasound, posterior capsule tightness often doesn't show up directly. What we may see instead are its downstream effects:
Bursitis
Rotator cuff tendonitis or tendinopathy
Calcification in the tendons
These are clues that something deeper is going on — and they often point us toward assessing the posterior capsule.
A common finding when the posterior capsule is restricted is a loss of shoulder internal rotation: the motion you'd use to reach behind you to pull up your pants, or to do up a bra strap.
The Shoulder Blade and Rib Cage Connection (The Most Commonly Overlooked Piece)
The contributors above are the more commonly discussed ones. But there are less commonly discussed contributors that frequently co-exist with everything above and often get missed — specifically, the shoulder blade, the rib cage, and the relationship between the two (joint called the scapulothoracic joint).
Your shoulder blade needs to move freely to accommodate normal rotator cuff function and overhead motion without pinching in the front of the shoulder.
When it can't — when it's expressing abnormal mechanics and doesn't have the freedom of movement it needs — this feeds directly into that anterior shoulder pinching that many people experience during shoulder CARs.
The Rib Cage as the Foundation
Going one layer (or set of bones) deeper, we have the rib cage.
Your shoulder blade, which forms the socket of your ball-and-socket joint, sits on top of your rib cage. The rib cage plays a critical role in determining where the shoulder blade sits in space and how well it moves.
We need what I'd call a congruent relationship between the two for the shoulder blade to slide and glide freely — which is what allows for normal shoulder or rotator cuff mechanics.
When we lose that — for example, when we've lost posterior rib cage expansion or the back of the rib cage has become quite flat over time — shoulder impingement tends to follow.
I see this most commonly in two groups of people. The first is those who have trained extensively in environments that emphasize keeping the shoulder blades pinned back — a high-alert or military posture — for extended periods. Over time, the posterior rib cage gets compressed, the upper back flattens, and those people become very good at keeping their shoulder blades back but lose the ability to let them move freely, separate, and protract.
The second group is ballet dancers, who are constantly coached to keep their chest up, shoulder blades back, and spine extended. When that position becomes the default off of the dance floor — it can come at the cost of normal shoulder mechanics.
In both cases, we've asked the spine to extend and the ribs to compress in the back so consistently that we've lost the foundation the shoulder blade and shoulder need to function normally.
The rotator cuff joint ends up paying the tab, and we feel it during shoulder CARs.
Shoulder Pinching During CARs Doesn't Always Mean Your Shoulder Is the Problem
This is one of the most important points here: shoulder pinching during shoulder CARs doesn't always mean your shoulder is the culprit.
It can mean your shoulder is paying a tab for something else in the system — and by system, I mean your body as a whole, because nothing functions in isolation.
When we do controlled articular rotations, we're trying to isolate a joint. But our inability to do so without symptoms doesn't necessarily mean the problem lives at that joint.
It means there's a problem somewhere in the system.
We start by looking at the joint in question, but we much pay close attention to what's immediately connected to it and influencing it.
These are not the only causes of shoulder impingement, but they are among the most common — and the most commonly overlooked.
What To Do About Shoulder Pinching During Shoulder CARs
If you're experiencing these symptoms, the first priority is modifying your shoulder CARs so they are pain-free. I've included a video here that walks you through exactly how to do that.
If you want to train the entire system by training your rib cage, shoulder blade, and shoulder together so your body can accommodate normal mechanics at each of those joints — you'll find entire classes and pathways in Operation Human First dedicated to exactly that process.
And if you're dealing with an acute injury, having a practitioner who can assess you and guide you based on your specific findings is invaluable.
If you need help finding someone trained in Kinstretch or well-versed in these concepts in your area, don't hesitate to reach out — we can point you in the right direction.
Frequently Asked Questions
Why does my shoulder pinch during shoulder CARs?
Shoulder pinching during shoulder CARs is most commonly caused by subacromial impingement, posterior capsule tightness, restricted shoulder blade motion, or altered rib cage mechanics. It's rarely one isolated issue and usually reflects a problem somewhere in the broader system.
Is shoulder pinching during CARs normal?
No. Pinching — or even just compression or congestion — during shoulder CARs is not a normal finding. It's a signal that something needs to be addressed and should not be pushed through.
What is the closing angle sensation rule?
The closing angle sensation rule is a modification of the closing angle pain rule. It means we treat feelings of compression or congestion just as seriously as pain — both signal abnormal contact or joint function that should not be pushed through.
Can the rib cage cause shoulder impingement?
Yes. The shoulder blade sits on top of the rib cage, and reduced rib cage mobility — particularly in the back — can directly alter shoulder blade mechanics and contribute to shoulder impingement.
What is the scapulothoracic joint?
The scapulothoracic joint describes the relationship between your shoulder blade and your rib cage. While not a traditional anatomical joint, the movement that occurs there plays a critical role in normal shoulder mechanics and overhead motion.
Written by: Alex Murphy | Physical Therapist, Kinstretch Instructor, FRCms, FRSC, FRAs, FR
This blog and content is for educational purposes only and does not constitute physical therapy, medical advice, or a patient-provider relationship. While the author is a trained physical therapist, nothing here should be taken as clinical guidance specific to your situation. If you're dealing with pain, please work with a qualified healthcare provider who can assess you directly.
