First off, it is not the "rotary cup." I actually hear it called that fairly often, but I usually let it slide.
The Four Muscles
The rotator cuff is a group of four muscles that work together to stabilize the shoulder joint. They are:
- Supraspinatus — initiates arm elevation and helps lift the arm away from the body
- Infraspinatus — the primary external rotator of the shoulder
- Teres minor — assists with external rotation
- Subscapularis — the primary internal rotator of the shoulder
What It Does
The rotator cuff's main job is to keep the head of the humerus (upper arm bone) centered in the glenoid (socket) during arm movement. Without the rotator cuff, the larger muscles like the deltoid would pull the arm bone upward, impinging the structures above it.
Why It Matters
The rotator cuff is critical for overhead athletes, weightlifters, and anyone who uses their arms. When it's weak or irritated, you may experience pain with reaching, sleeping on your side, or lifting overhead.
If you're dealing with shoulder pain, book a free phone consultation and let's figure out what's going on.
— Dr. Caleb