What Is It?
Four tendons attach muscles from the shoulder blade and ribs to the upper arm bone (humerus). Because these tendons help to rotate the arm within its socket, this sleeve of tendons is called the rotator cuff.
Tendons in the rotator cuff can be injured easily because they move within a tight space. When the shoulder is turned or lifted at the limit of its natural range of movement, the tendons in this tight space are moved, too. Occasionally, the rotator cuff tendons can bump or rub against a bony knob (the acromion) above them or against a ligament at the front of the shoulder.
To continue reading this article, you must log in.
Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.
- Research health conditions
- Check your symptoms
- Prepare for a doctor's visit or test
- Find the best treatments and procedures for you
- Explore options for better nutrition and exercise
I'd like to receive access to Harvard Health Online for only $4.99 a month.Sign Me Up
Already a member? Login ».
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles.
No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.