The Rotator Cuff and The Shoulder Explained

Do you have a bad rotator cuff? How about a “torn” rotator cuff?

Do you know what the heck the rotator cuff is?

There’s a lot of confusion about the rotator cuff out there. Heck, people will even get a diagnosis from a doctor and have surgery without understanding the anatomy of the shoulder or what their problem actually is.

Let’s clear up the mystery once and for all.

We’ll talk about shoulder anatomy, the muscles of the rotator cuff, and some common issues and treatments for rotator cuff symptoms and injuries.

Image courtesy of: Central Coast Orthopedic Medical Group

The shoulder joint is a work of art. Well done God. It’s complex, elegant and provides the most versatile range of motion of any of the joints in our body.

At its most basic level, the joint is a ball and socket configuration that consists of bones, ligaments, tendons, muscles, nerves, blood vessels, and bursa.

The bony makeup of the shoulder includes 3 different bones:

1. Humerus (upper arm bone),

2. Scapula (shoulder blade)

3. Clavicle (the collar bone.)

The top of the shoulder joint is formed by the tip of the scapula called the acromion.

These bones make up 4 different joints:

1. Glenohumeral Joint - The ball and socket joint where the “ball” of the humerus sits in the shallow recess of the scapula called the glenoid

2. AC Joint - The small joint where the clavicle meets the acromion

3. SC Joint - The connection where the clavicle meets the sternum on the front of the body

4. Scapulothoracic Joint - a “false” joint supported by the shoulder muscles where the shoulder blade glides against the rib cage on the back of the body

Cartilage covers the ends of the bones to provide a slippery surface that allows the bones to absorb shock and glide smoothly against each other in the joint.

Ligaments in the shoulder connect bone to bone and form a water tight capsule between the humerus to the glenoid to provide stability to the shoulder and keep it from popping out of alignment. They also attach the clavicle to the acromion in the AC joint.

A special, unique ligament forms a structure inside the “socket side” of the scapula (glenoid) called the glenoid labrum. This labrum attaches around the outside socket that provides the “cup” that the humerus head rotates in. Pretty rad, right?

Tendons connect muscles to bones and make the joints move.

In the shoulder, the biceps tendon crosses over the head of the humerus, through the top of the shoulder joint and then attaches to the labrum inside the back of the joint.

4 other tendons connect the “rotator cuff” muscles to the humerus. These 4 tendons join together to form a single tendon as the attach to the humerus. We call this the rotator cuff.

There are 4 muscles of the rotator cuff:

1. Supraspinatus

2. Infraspinatus

3. Teres Minor

4. Subscapularis

These muscles help raise and rotate the arm. They also serve to stabilize the joint by holding the head of the humerus tightly in the glenoid socket of the clavicle.

The deltoid (outer shoulder muscle) is the largest muscle of the shoulder. It provides the power to lift the arm out to the side once it’s outside the body, like when you do a lateral raise with a dumbbell.

4 main nerves innervate the shoulder sending the electrical signals to the muscles:

1. Radial Nerve

2. Ulnar Nerve

3. Medial Nerve

4. Axillary Nerve

These nerves connect the brain to the muscles sending messages in both directions. One direction allows the brain to control the muscle and the other direction tells the brain that there is sensation like pain or temperature.

In between the tendons of the rotator cuff and the deltoid muscle are bursa. Bursa are fluid filled sacks that provide a cushion against friction where two surfaces in the body that need to move come together.

Whew!

I know that was a lot to get through but I think it’s important to know the anatomy of the shoulder so that when you hear terms or diagnoses thrown around you can visualize what’s going on or know if someone doesn’t know what they are talking about.

Obviously, it’s a complicated joint and things can go wrong.

Let’s talk about some common injuries of the shoulder/rotator cuff.

1. Tendinitis of the rotator cuff tendon(s) - This is an inflammation of one of the tendons of the cuff (or the main cuff tendon itself). This is typically the result of a traumatic injury or an overuse of the tendon from repetitive use. An example of this would be a mechanic who works over their head for many hours or a baseball pitcher who performs the same task over and over. Typical symptoms of tendinitis in the shoulder would be acute pain at the site of the tendon attachment to the bone and pain in the shoulder when passing the arm through specific ranges of motion. Oftentimes, muscular function is inhibited with severe cases of shoulder tendinitis.

2. Bursitis of the shoulder - This is an inflammation of the bursa sack in the shoulder. This can also be caused by overuse of the joint and the symptoms are similar to tendinitis. When the bursa is inflamed it does a poor job cushioning the joint and instead causes pain.

3. Labrum Tears - Remember that the labrum provides the “cup” that the head of the arm moves around in. The edges of that cup can tear. A tear above the middle is called a SLAP tear. A tear below the middle is called a Bankart tear. Less common is a tear to the rear of the labrum called a Posterior Labrum Tear. - Symptoms of a labral tear can include catching, grinding, or popping of the shoulder while moving, acute pain, and decreased range of motion. Labral tears vary in degree and severity and can be caused by both acute trauma and overuse.

4. Tendon Tears - Remember that there are 4 tendons/muscles (plus the bicep tendon) that make up the rotator cuff. These tendons can sustain tears of varying degrees and thickness in them at different places along them. Symptoms of a torn tendon can include localized pain, loss of strength, and pain when moving the arm through a range of motion.

5. Arthritis - This is when the smooth cartilage that provides the “glide” between the bones deteriorates causing a painful friction in the joint. Arthritis can both be caused by the aging process and as a result of an auto-immune disorder.

Alrighty then. As you can see, it’s pretty danged complicated. When someone tells you they have a “torn shoulder” or a “bad rotator cuff”, it can mean a whole lot of things.

It seems like keeping the shoulder healthy is pretty important since there are so many things that can go wrong with it. But what does that mean, and what does that look like in real life?

WHAT YOU CAN DO TO HELP YOURSELF

If you look back at the most common injuries there was a common theme. Overuse.

If you do a repetitive motion with your shoulder joint such as reaching up or out as part of your job, you should consider limiting that specific range of motion in other parts of your life. If you’re exercising and training with weights (you should be!) your training program should take overuse of specific movement patterns into consideration. With the shoulder, the most notorious things we see are overdoing movements like the overhead press and the bench press. We are NOT saying that you should avoid these movements, but rather not OVERDO them. If you’re repeating the same movement pattern 5x per week, you’re probably overdoing it.

Now that overuse is out of the way, another thing we can be actively doing to help ourselves build and maintain shoulders is to strengthen ALL of the muscles surrounding the joint.

I emphasized ALL, because some of the smaller muscles of the rotator cuff like the supraspinatus may become weak and underdeveloped in relation to the larger muscles like the deltoid, and the “pushing” muscles of the chest. You don’t need to design your entire workout program around keeping these muscles strong, but you should include some exercises like face pulls, band pull aparts and band external rotations in your warm-up a few times per week in addition to your training. Some other popular exercises for shoulder health are snow angels, T’s, and Y’s with light weights.

Another way to help yourself have healthy shoulders is by maintaining good flexibility and range of motion in both of your shoulders, arms, and upper back.

Again, these can just be a part of your warmup a few days per week. Keeping the thoracic spine from getting excessively arched forward over time with some foam roller stretches can feel great. Door jamb stretches to keep the chest from being tight work well. Stretch your triceps with this stretch also.

WHAT IF YOU’RE HAVING PAIN NOW?

We can’t assess you with a lot of reliability over the internet, but we have some helpful guidelines that you can use if you’re already having shoulder pain.

First off, if you’ve suffered an acute injury or are having intense pain you should see a doctor or go to the hospital ASAP. If you’re suffering with more of a chronic nagging issue that just won’t seem to go away, here are some steps that you can take.

1. Stop doing things that hurt and/or make it worse. If you have an inflammation-based condition like bursitis or inflammation you need to let the area chill out a bit. Do similar movements that stimulate the nearby muscles and tissues but do not aggravate the injury. This might be as simple as rotating your hands at a different angle to change the direction that the arm is moving. Another idea is to test out using bands like Thera-bands for resistance vs. weights.

2. Soft tissue like tendons and ligaments are notorious for having poor blood flow which is a bummer cause blood brings healing to injured tissue. That being said, it’s still important to continue using the affected areas in a progressively challenging manner to stimulate blood flow and thus healing. Add resistance and volume (more reps) as you can. Let pain be your guide. Work toward the goal of surpassing your pre-injury strength level.

3. Strengthen the supporting muscles around the injury and work to correct imbalances. Consistent strength around the whole shoulder joint is key as it’s crucial for the humerus to remain centered in its socket for optimal shoulder health. We do this by having strong and balanced musculature around the joint as well as working to maintain correct posture which includes keeping the shoulders “back” vs rolled forward.

We’ve been able to help countless people resolve shoulder pain following these principles.

You might be thinking “What about tears? Don’t I need surgery?”

A 2014 study done at Harvard University looked at the prevalence of shoulder abnormalities (including tears) in 4331 aging patients. The authors found a “high rate” of abnormalities in both symptomatic and asymptomatic participants, with the highest percentage in the 30 years old and up range. What does this mean? It means that whether you have shoulder pain or not, if you have an MRI done of your shoulder you might have things like inflammation and tears present.

I know, I didn’t answer your question yet. “Don’t I need surgery?” Maybe, maybe not. A 2017 meta-analysis of 3 studies (a combination and subsequent review of all studies combined) compared the effectiveness of rotator cuff repair surgery to more conservative rehabilitative efforts. At a one-year follow-up, there was no clinically significant difference in pain between the people that had surgery and those who didn’t. With the risks associated with any surgery we always recommend people think long and hard as well as exhaust all other options before going under the knife. Sometimes it’s necessary, but sometimes it’s not.

THE BOTTOM LINE

Let’s summarize what we’ve learned about the shoulder, shoulder injury, and shoulder health.

1. The shoulder is an extremely mobile ball and socket joint supported by a series of small tendons and muscles that make up what is called the “rotator cuff”.

2. Keeping these muscles strong helps keep the shoulder in proper alignment which can help prevent injury.

3. Maintaining a normal range of motion along with strength can help prevent imbalances, overuse due to compensation and other injury.

4. Once an injury is sustained it must be evaluated. Take a conservative approach following a “progression over time” model.

5. Limit the risk of injury with balanced training that avoids overuse of movement patterns.

Hopefully, you’re walking away from this article with a better understanding of the shoulder. It’s not simple, and when you hear people use non-specific terms like “I tore my shoulder” or “I have a bad rotator cuff” you’ll know now that there’s more to the story.

If you need a training program to come back from a shoulder injury send us an email. We can help.