What is the rotator cuff?
Your shoulder is a ball-and-socket joint. The “ball” is the head of the humerus (upper arm bone). It fits into the “socket” of your shoulder blade.
The rotator cuff consists of muscles and tendons that hold the ball in the socket. The rotator cuff allows the shoulder to rotate safely while staying stable.
Parts of the Rotator Cuff
What are the parts of the rotator cuff?
The rotator cuff contains four muscles:
- Supraspinatus controls internal rotation and lifting of the arm.
- Infraspinatus allows you to externally rotate your arm in the shoulder socket.
- Teres minor is a small muscle that helps rotate your arm.
- Subscapularis controls arm abduction (holding your arm out straight, away from your body).
The muscles start at the shoulder blade. Tendons (strong bands of tissue) attach the muscles to bones. The tendons wrap around the head of the upper arm bone, forming a cuff that keeps your arm in the shoulder socket.
Which muscle is not part of the rotator cuff?
The teres major muscle is not part of the rotator cuff, although it is frequently confused with other muscles in the rotator cuff. The teres major performs similar functions to some of the rotator cuff muscles. Its job is to help with internal rotation of your arm inside the shoulder socket.
Injuries to the teres major muscle are much less common than injuries to the rotator cuff muscles.
Frequently Asked Questions
Common Conditions & Disorders
What causes problems with the rotator cuff?
Age, overuse and injury can lead to inflammation or tears in the rotator cuff tendons. Rotator cuff injuries can be degenerative (from wearing down of the tendons over time). Or they may be acute (the result of a sudden injury).
What are common rotator cuff injuries?
Rotator cuff injuries are very common. The two most frequent injuries are:
Rotator cuff tendinitis (inflammation) often results from repetitive overhead motions such as throwing a ball, swimming or swinging a racket.
An acute injury — such as falling or lifting something heavy — can tear rotator cuff tendons. But in most cases, rotator cuff tears also occur gradually over time.
As we age, tendons thin out and wear down. Blood supply to the shoulder tendons also slows down. As a result, tiny tears don’t repair themselves as effectively. Playing a sport or doing a job that requires repetitive overhead motions can also lead to tears over time.
How are rotator cuff conditions diagnosed?
Your provider will begin with a physical exam, including checking your range of motion. If your provider suspects you may have a rotator cuff injury, you’ll have imaging tests, such as X-ray, MRI or ultrasound.
How are rotator cuff conditions treated?
Treatment for rotator cuff tendonitis or a rotator cuff tear varies depending on the severity of your injury. Minor injuries may heal with simple, at-home care, such as:
- Avoiding activities that cause shoulder pain.
- Applying ice or heat.
- Taking nonsteroidal anti-inflammatory drugs (NSAIDs) or other medications.
For more serious injuries, your provider may recommend one or more of the following as part of your treatment plan:
- Physical therapy to strengthen the muscles that support your shoulder joint.
- Steroid injections to reduce swelling.
- Surgery to repair torn rotator cuff tendons.
Caring for Your Rotator Cuffs
How can I keep my rotator cuffs healthy?
You can take steps to help avoid rotator cuff injuries, including:
- Exercises to strengthen your shoulder muscles.
- Gentle stretches to keep shoulders flexible and increase range of motion.
- Standing on a step stool or ladder to avoid prolonged reaching and overhead motions.
- Taking extra care to prevent falls that could injure your shoulder.
When to Call a Doctor
When should I call my doctor about rotator cuff problems?
You should call your healthcare provider if you experience:
- Pain that keeps you from doing your job or activities you enjoy.
- Sudden, intense shoulder pain — especially after a fall or other injury.
- Pain that makes it uncomfortable to sleep on the affected shoulder.
- Weakness in your shoulder.
What should I ask my doctor about my rotator cuffs?
You may want to ask your healthcare provider:
- What can I do to strengthen my rotator cuff muscles?
- When can I return to the activities that caused my rotator cuff injury?
- How can I treat my rotator cuff injury at home?
- Will I need surgery to repair my rotator cuff?
A note from Cleveland Clinic
The muscles and tendons that make up the rotator cuff help keep your shoulder joint stable while allowing it to rotate. Inflammation (tendinitis) and tears are common rotator cuff injuries. Minor rotator cuff injuries can heal with rest, physical therapy and anti-inflammatory medications. More severe injuries — such as rotator cuff tears — may need surgery.
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