Shoulder pain may not seem like too big of a deal, but it is a common and debilitating issue. Up to 70% of people will deal with shoulder pain at point in their life. The effects depending on the injury can limit your function, keep you from doing the activities you want to do, and decrease your quality of life.
I'm not about that. As a Physical Therapist, I pride myself on giving you the tools to know what the shoulder does, what this complex body part is made from, how these parts can go wrong, and how you can treat it effectively. Keep reading to learn more about this complex part of your body!
The Shoulder: Troubleshooting Guide
When a computer has trouble running, the IT person knows the most common reasons for breaks down. Similar to that, Physical Therapists know the most common reasons why and how your shoulder hurts. During this portion of the blog, I'm going to list a few ways this dynamic joint can go wrong and why it happens. To do this, we need to review the anatomy of the shoulder first so you don't get lost. But if you do get lost, take a couple seconds to google these muscles or joints, so you can picture them better!
First step, let's rule out the serious stuff.
Most of you are healthy other than your painful shoulder and your goal is to get back to the gym. If you start having shoulder pain "out of the blue" and can't reproduce the painful arm movement, we want to make sure it's not referred pain. Your heart refers pain when it's not getting enough oxygen. Referred pain can happen in the left shoulder, chest, neck, and even upper back.
See your primary care physician if:
- You can't reproduce the pain with arm motions, and/or;
- You have any shortness of breath, heavy chest, dizziness, fatigue, or nausea.
Let's make sure your symptoms aren't more than muscle and joint pain.
Now that we got that out of the way, lets get to the nitty-gritty. The shoulder has some of the most dynamic movements of any body part, period. In order to do all of these movements, the shoulder needs many coordinating working parts. Your golf swing, shoulder press, rows machine, and grabbing that can of soup from the top shelf may use 15 to 20 different joints, which are all moving together.
For now, let's cover the main ones.
1. Glenohumeral Joint
The glenohumeral joint or the ball in socket joint - is the star the show. And is normally where everyone points to when I say "can you show me your shoulder"? The upper arm, called the humerus, makes half of this joint and it's ending acts as a ball. This "ball" sits in a "cup" called your glenoid, that is part of your scapula, also called your shoulder blade. This perfect fit allows the shoulder to move in almost any direction.
But the trade-off for such a well moving joint, is that it isn't very stable. Ball in socket joints are naturally less stable the other joints, so they need other back up systems to keep everything secured. Your shoulder is surrounded by ligaments that passively keep your glenohumeral joint tight in its socket. These ligaments are located in the front, back, and top of your ball in socket joint and make the "cup" deeper for your shoulder to sit in.
By passively, I mean these ligaments only pull a certain amount of force no matter the movement and do not actively contract. If they get stretched out, they may not be able to re-tighten. The main way these ligaments become stretched out is by dislocating your shoulder or shoulder instability. Instability happens when your shoulder isn't staying in that "cup" as tightly as before.
There are quite a few directions this can happen but typically the shoulder dislocates forward or downward, because these are the weakest and the most injury prone areas. Dislocation can lead to the humeral head or "ball" slipping out of the socket so hard, it can fracture or break off bone from the shoulder socket.
Ligaments aren't the only system that stabilizes your shoulder. Luckily your body knew that we need something else that wraps around the shoulder joint similar to ligaments, to automatically stabilize during the most strenuous shoulder movements.
These structures, just like your ligaments, attach to the top, front, and back of the shoulder. They are known as your rotator cuff muscles and we have four of them. These muscles start by covering most of the front and back of your shoulder blades and also wrap around the shoulder. Not only do they help the shoulder rotate in and out, but they also keep it from rolling out of the socket. Sounds important right?
These muscles aren't very big, but if they get irritated they can feel like someone is poking a sharp knife in the back of your shoulder. This can happen from reaching out while falling, lifting something that is too heavy, sudden jolting movements, or with general wear and tear.
When these injuries happen, our shoulders aren't as supported. The rotator cuff muscles don't pull on the humeral head as it moves causing the shoulder to become more unstable and painful. This creates more pain with overhead motion and limited strength when lifting objects.
So you may be thinking: are all of the issues with the shoulder coming from the joint moving too much? Mostly, but there is one major shoulder condition that actually causes the opposite effect - causing the shoulder to get stuck.
Your shoulder is what we call a synovial joint, which is what most of your major joints are classified. A synovial joint has a "capsule" that the joint sits in, this capsule is full of fluid and lined with cartilage. The cartilage makes the endings of the joint nice and smooth and the fluid acts like how oil works in your car engine. The combination of the cartilage and fluid creates the most supported, smooth running joint that handles a ton of wear and tear.
The joint lining is where this condition called frozen shoulder occurs. This can happen for multiple reasons, but it always involves the shoulder capsule getting inflamed to the point where it starts creating scar tissue.
2. Scapulothoracic Joint: Your Shoulder Blade
We talked about several conditions that happen with the first and main joint of the shoulder. But as you now know, the shoulder joint sits like a golf ball on a tee. If the tee is out of alignment, it effects how stable that shoulder is.
This "tee" is actually part of your shoulder blade or scapula. The scapula sits on top of your rib cage and connects to a whole host of different muscles. This lets it glide and rotate over the top part of your back. Just roll your shoulders or raise your arm overhead in front of a mirror and you can see what I'm talking about. The scapula and thoracic spine, or the spine that attaches to your ribs, has an indirect connection through all these muscles.
What muscles attach to the shoulder blades you ask? Your pectoralis muscles, trapezius, rhomboids, rotator cuff muscles, latissimus dorsi, and parts of your biceps and triceps, to name a few.
Your shoulder blades act as a mobile base for all of these muscles to attach, creating stability in the shoulder. But this mobile base can quickly become limited into a forward shoulder posture. We all become accustomed to this posture at our desk jobs, watching TV, or looking at our phones.
This change in mobility in our shoulder blades can lead to certain muscle attachments becoming strained or overused, causing pain in or around the shoulder blades. This can also lead to certain rotator cuff muscles becoming pinched, irritated, and even tearing. This is why your shoulder blade mobility is so important.
Now I mentioned before that your shoulder blade also attaches to your ribs and mid-spine, also known as your thoracic spine. This is where the shoulder changes from a simple joint to a complicated one. Through muscles and ligaments, your shoulder blade pulls on over 12 thoracic spinal joints, the 12 ribs and their joints, the chest attachments of those ribs into the front, all 7 of your neck joints, and your skull.
I may be missing a few, but we are at 37 joints right now that are connected and affected by the shoulder blade. An issue with the shoulder blade could be felt in the shoulder, low back, ribs, or neck. It could also cause headaches, numbness, tingling, painful breathing, pain in between the shoulder blades, or chest pain. Officially complicated as hell, right? My head is spinning just writing this.
Your thoracic spine is primarily responsible for almost all the turning or rotation of your trunk. Believe it or not, there really isn't a time that you raise your arm and don't rotate at least some of your thoracic spine. Your ribs are similar and can spread or collapse on each other. This isn't only for adequate breathing and oxygen intake, but to allow the shoulder more flexibility with various overhead or reaching tasks.
If these two structures become sprained, strained, fractured, or just become stuck, it could limit up to half of your shoulder motion.
This is why if you do have pain in between the shoulder blades, it pays to have a professional look at all of these connect joints. This includes mobility, posture, daily requirements of the shoulder, muscle performance, and range of motion. The number one priority is to figure out the primary cause of your shoulder blade pain. This is a difficult one to figure out on your own!
3. Collar Bone or Clavicle
The other part of your shoulder that is probably the least mentioned is your collar bone or the clavicle. Your collar bone attaches to your sternum in the front of your chest wall. It also runs overtop and protects the nerves responsible for moving as well as sensation down your arm. Most people don't think the shoulder has two ball and socket joints, but if your follow along the attachment of your collar bone to your chest, you will feel a mini ball in socket joint called the sternoclavicular joint, that rolls upward, downward, and side to side as your raise your arm.
Through this joint your shoulder attaches to the chestbone and front of your ribs. Another key attachment of the clavicle is to your pectoralis major (pecs). This powerful muscle not only is responsible for pushing, but also elevation and stabilizes across your entire upper chest wall. Your pectoralis even has indirect pull into your core through your body's connective tissue.
Your collarbone also attaches on the other end into the scapula or shoulder blade through a bony outgrowth called the acromion. The clavicle attaches through multiple ligaments to create you acromion clavicular joint or AC joint. This joint amazingly allows your shoulder blade to be able to do even more movements like rotation and even tilting forwards and backwards!
This joint has a lot of small but important ligaments to keep it stable but flexible. Unfortunately, this joint has a weakness, which is exploited when you fall directly onto your shoulder. This direct force can lead to rupture of these ligaments or of the joint.
There are different grades of sprains relating to how many ligaments are torn. If the injury is minor, you may be able to get away with rehabilitation, but if it gets bad enough surgery may be needed.
4. The Unofficial Part of Your Shoulder: Cervical Spine
I wanted to dedicate a small section of this blog to your neck, because even though it technically isn't part of your shoulder joint, it might as well be one. The connections between your neck and your shoulder are so vast that any practitioner who isn't ruling out a neck issue with shoulder pain is missing a huge piece of the puzzle.
Your neck is essentially seven spine segments that rotate, bend, extend, side bend, and stabilize to provide a solid base for your shoulder to move. It also supplies the nerves that are responsible for moving all of the muscles in your arms, and all of your feeling in your arms. Oh, and by the way, it also protects your spinal cord, keeping you from becoming a quadriplegic. Not bad right?
Your cervical spine could be a whole separate blog, but I thought it was at least worth a mention here!
As I said earlier, this guide is meant to increase your knowledge of the shoulder joint and how it connects and functions all as one. With this being said, the shoulder is a lot of moving parts. To make it even more confusing, these these parts can refer pain into different regions of the body. What you're feeling may be occurring at the specific area that hurts, but it could also be referred from a different part of your body.
If it has been a few weeks and you still haven't made headway or don't know what this issue is, it pays to have a Physical Therapist evaluate you. Hell, even a medical professional, like me, sometimes needs a second pair of eyes to understand what is actually going on.
A trained Physical Therapist is truly a movement expert. We can evaluate your motion, strength, posture, joint mobility, and test all of these body parts I previously mentioned. Want to learn more? Send us an email at firstname.lastname@example.org!