rotator cuff disorders develop gradually, from aging,
continued overuse, repetitive activity, or a combination of these things.
The rotator cuff is a group of four tendons. These tendons
connect the main muscles of the shoulder-the supraspinatus, infraspinatus,
subscapularis, and teres minor-to the upper arm. The rotator cuff tendons and
muscles stabilize the
shoulder joint and allow you to raise and rotate your arm. Every time you raise
your arm above your head, the upper
tendon in the rotator cuff (supraspinatus tendon) and
bursa, which lies on top, glide on the underside of
the upper end of your shoulder blade (acromion). The undersurface of the
acromion may be rough or abnormally shaped and rub or scrape (abrade) the bursa
and tendon. Activities that require repeated overhead arm movements can result
in painful inflammation of the bursa (bursitis)
and/or the tendon (tendinitis).
the tendon may rub against the undersurface of the acromion, causing tiny tears
and bleeding, causing the entire rotator cuff to weaken. Finally, the tendons in
the rotator cuff can no longer balance the upward pull of the muscle in your
shoulder called the deltoid. This can lead to further damage to the tendon. The weaker the tendon
becomes, the more susceptible it is to partial or complete tears.
Without treatment, inflammation and tears can build up, resulting in pain and loss of function. This cycle of
inflammation, wear and tear, and limited use can lead to other shoulder
problems, such as stiffness or
frozen shoulder (adhesive capsulitis).
Rotator cuff tears generally occur when the related tendons become weak
from inflammation or fraying. Tears often result from slow,
progressive damage over time, often without a known injury. In older, less
active adults, even simple movements such as lifting a suitcase can cause a
It takes tremendous force to tear a healthy rotator cuff
tendon. This may happen while you are playing sports or during an accident or a