There are four rotator cuff muscles whose tendons surround, or cuff, the head of the arm bone and form the notorious 'Rotator Cuff'. These muscles are responsible for rotating the arm, inward and outward. Hence, they are called 'rotators.'
All rotator cuff muscles also stabilize the arm bone in its socket. Left untreated, the symptoms of most RC injuries will become progressively worse. In most cases, the Supraspinatus tendon first becomes damaged in some way (tightness, trauma, inflammation). This leads to the overlying bursa becoming inflamed. Normal function of the shoulder is then impossible due to impingement of the tendon.
Let's look at each of these muscles and their tendons.
#1: Infraspinatus, which means "inferior to the spine" (of the scapula),
lies right over the scapula. See the image on the right. The "Infra"
rotates your arm out at the shoulder joint and stabilizes your arm bone
in its socket.
When "Infra" contracts, your shoulders are pulled back and your arms rotate out as in the common "Good Posture" movement, i.e. straighten your slouch.
When you hunch over, the "Infra" is stretched taut like a drum. Overtime it loses its strength and elasticity. That's why it's so easy to slouch!
Sometimes we hear our clients say: "Ouch! You know exactly where to press!" Here is a little trade secret: it's not so hard if you know where the "Infra" is located. It's painful on most people within most of its fibers.
The "Infra" becomes injured when pulled or tugged beyond its natural length.
The muscle attaches to the whole surface of the scapula, narrows into a tendon behind the shoulder joint, and inserts on the head of the arm bone. This insertion, together with 3 other muscles, forms the notorious "Rotator Cuff" that cuffs, or surrounds, the head of the arm bone.
It's at this insertion point that most serious injuries occur. The "Infra" tendon tears off the bone attachment, sometimes completely, but usually only partially. This is where all that scar tissue builds up.
Our work as therapists is to remove the scar tissue, deactivate the trigger points, and send you to a good trainer or PT who can show you how to strengthen this muscle.
#2: Subscapularis. While the Infraspinatus is full of painful trigger points that make you jump off the massage table, the Subscapularis is one of those ultra-sensitive muscles that, upon pressure, makes you turn white, stops your breath, and you immediately want to hit your therapist. Please don't! There is hope...
The "Subscap" is a common culprit for shoulder injuries and pain. To access the Subscap can be difficult due to its location underneath the scapula, and a client's shoulder blade mobility.
Therapists are able to access the attachment of the Subscap on the arm bone (see image).
The Subscap attachment is deeper than the chest Pec muscles. So your therapist must gradually 'melt' through the Pecs to work on the Subscap.
Working at the attachment helps to break up scar tissue associated with any micro tears in the muscle. The scar tissue usually builds up around the attachment.
Often, it's the muscle itself underneath the scapula that needs work. That's where all the trigger points hide and send painful sensations down the arm, up to the neck, or the front of the shoulder.
We free up the tissue in the back surrounding the scapula first, and then try to traction the scapula out as in the photo. This way, the lateral fibers of the Subscap become available for compression and friction.
Pain here can be very sharp and shoot into the neck, or
the front of the shoulder.
Pressing into the trigger points helps to flood them with blood flow and release the pain.
In some people, the Scapulae are glued to their backs. Sometimes we can't even tell where the scapula is. It's especially difficult to release the Subscap muscle for those people.
Typically it takes a few massage sessions just to create adequate mobility in the scapula first. Then, we can focus on releasing the trigger points, and removing any scar tissue.
What can you do to help the process?
Make your scapulae more mobile. Stretch it. Strengthen it all around. Explore (gently) all movements that involve the shoulder and the scapula.
#3: Supraspinatus means above/superior to the spine (of the scapula), and sits right inside the groove above the shoulder blade. See image.
Its tendon dives under the shoulder bone (acromion) and attaches on the arm bone.
When you carry heavy bags when traveling or moving, your Supraspinatus may get strained.
The "Supra" helps to lift your arm out to the side (abduction). It actually starts that movement to about 20-30 degrees up, until the Deltoids take over.
When the arm is slightly lifted off to the side of the body, it's mostly all Supra. Once you get it up to be parallel to the floor, the stronger Deltoid muscles control the movement.
When you carry a heavy bag, your Supra is working extra hard. It's a small muscle and easily fatigues.
The Supra may also get strained when bag straps are hung over it. Heavy bags stretch its fibers beyond its comfortable limit. If strained for a long period, as in traveling, the muscle will go into a chronic spasm.
Usually, it feels really sore when pressed right on top - over the spine of the scapula.
Cross your arm over the opposite shoulder and dig your fingers into
the groove right over and all along the bony spine of scapula. Picking
through different fibers may send a sharp radiating sensation to your
neck or down the arm - you've hit a trigger point!
But why do it yourself?!
Let a professional massage therapist figure out where those triggers
The attachment of the Supra on the arm bone gets strained and torn, too.
Its tiny fibers tear off the arm bone attachment when loaded unexpectedly - as in picking up a heady load quickly.
The best technique to treat the tears and scar tissue is cross-fibering across that attachment but first you would need to know how to locate it among the other 4 rotator muscle attachments. There is an easy way to do that, but again that is why you would come here to get it worked out.
How to Avoid Straining the Supraspinatus?
- Use a rolling suitcase
- Don't pack too heavy - let your bags be light enough to carry
- Warm up the shoulder joint before lifting with some simple range of motion arm swings and circles.
#4: Teres Minor gets overlooked because it gets overshadowed by the stronger muscles around it like the Infraspinatus and the Teres Major.
Yet, to be able to do a handstand, you would need to have a strong Teres Minor. Even though Teres Minor is small and the weakest of all 4 rotator cuff muscles, it plays an important role in balancing and stabilizing your arm and shoulder when you are upside down on your hands if you ever tried such a feat.
Teres Minor attaches at the lateral border of your shoulder blade, and inserts at the arm bone to form the rotator cuff. See the anatomy image.
When it contracts, it rotates your arm out (external rotation). It performs the exact same movement as the Infraspinatus.
This muscle may get injured and torn when stretched beyond its limit as in swinging a tennis racket overhead without any warm up, or doing a handstand without preparation.
To treat Teres Minor, we work through all of its fibers including the attachments to remove any possible scar tissue and restore blood flow.
How to Avoid Straining or Tearing Teres Minor?
- Warm up with basic arm and shoulder range of motion exercises before any exercise.
- Before attempting a handstand, make sure you can hold Downward-facing Dog for 2 full minutes. We use very similar muscles there. See the image.
- Build up to 10 pulls up on a high bar - if you can do 10, your Teres Minor is strong enough!