Muscle guide · Chest and shoulders
Also called SITS muscles, shoulder cuff
The rotator cuff is four muscles from the shoulder blade whose tendons wrap the ball of the upper arm bone and blend with the joint capsule: supraspinatus, infraspinatus, teres minor and subscapularis (SITS).
The shoulder is a shallow ball-and-socket joint, and the cuff's main job is to press the ball into the socket and keep it centred while the bigger muscles move the arm.
| Part | Starts at | Attaches to | What it does |
|---|---|---|---|
| Supraspinatus | The hollow on the back of the shoulder blade above its ridge | Top of the outer bump of the upper arm bone, under the shoulder tip | Helps start lifting the arm out to the side; the most often torn |
| Infraspinatus | The back of the shoulder blade below its ridge | Middle of the outer bump of the upper arm bone | Turns the arm outward |
| Teres minor | The outer edge of the shoulder blade near the armpit | Lower part of the outer bump | Turns the arm outward; resists the ball slipping forward |
| Subscapularis | The front surface of the shoulder blade, against the ribs | The small bump on the front of the upper arm bone | Turns the arm inward; the largest and strongest of the four |
Side-lying external rotation produced the most infraspinatus and teres minor activity of seven exercises; a thumb-up scaption raise ('full can') worked the supraspinatus as well as the thumb-down version with less deltoid; push-up plus and diagonal patterns worked the subscapularis more than plain internal rotation.
3D demoSide-lying external rotationBeginner · A dumbbell
3D demoStanding band external rotationBeginner · A band + An anchor point
3D demoScaption raiseBeginner · A dumbbell
3D demoIncline reverse fly with external rotationIntermediate · A dumbbell + A bench or box
3D demoBand internal rotationBeginner · A band + An anchor point
3D demoScapular push-up (push-up plus)Beginner · No equipmentIn a trial of people with tight shoulders, the cross-body stretch improved inward rotation by 20 degrees in 4 weeks; the sleeper stretch's gain was not significant.
A spectrum from irritated tendon to chronic tendinopathy and tears, typically felt as pain on the outside of the shoulder with overhead use, a painful arc as the arm rises, and pain lying on that side at night. Common in overhead athletes and workers.
Keep the shoulder gently moving; recovery can take six months or more.
Most tears involve the supraspinatus. Some follow a fall or a jerking lift, but most are wear-related and more likely after 40, and some cause no pain. Non-surgical treatment relieves pain and improves function in about 80 to 85% of people; a surgical opinion is suggested if symptoms persist after 3 months of good conservative care.
Each grade rates the evidence for the correction.
On MRI, 34% of people with no shoulder symptoms had a cuff tear, rising to 54% over 60. Across 6,112 shoulders, cuff changes rose from about 10% at 20 to 62% at 80 regardless of symptoms; the authors call it a normal part of ageing.
Thumb-up, thumb-down and lying versions worked the supraspinatus similarly; the thumb-up 'full can' used less deltoid, so it may be the better choice.
Source 14
It helps steady the joint but is not a cuff muscle; the cuff's 'teres' is the teres minor.
Source 6
A shoulder workout for all three heads: overhead press, lateral raises, reverse flyes, face pulls and rotations.
40 minIntermediate8 movesA band, A barbellEight gentle neck and shoulder stretches for desk stiffness, done standing or seated in ten minutes.
10 minBeginner8 movesA wallSupraspinatus, infraspinatus, teres minor and subscapularis, remembered as SITS.
It presses the ball of the arm bone into the shallow socket and keeps it centred as you move, and turns the arm in and out.
Side-lying external rotation worked the infraspinatus and teres minor most of seven exercises; a thumb-up scaption raise works the supraspinatus with less deltoid.
Usually not: non-surgical treatment helps about 80 to 85% of people. Tears are also common in people without any pain.
Anatomy and movement education, not a diagnosis or treatment plan. If you have pain that follows an injury, is severe or getting worse, or comes with numbness, weakness or swelling, get it assessed. Health disclaimer.
