The rotator cuff is a group of muscles and tendons that are responsible for the
glenohumeral (shoulder) joint’s stability while it moves and rotates.
The rotator cuff includes the
Supraspinatus, Infraspinatus, Teres Minor, and the Subscapularis muscles as well as their associated tendons. Of these, the supraspinatus and infraspinatus tendons are the most commonly injured.
When healthy, these tissues surround the shoulder joint and keep the head of the humerus (upper arm bone) in place during movement.
As a result, injuries to the rotator cuff are usually related to sports that require excessive shoulder rotation, such
as swimming, baseball, or bowling.
Problems with rotator cuff muscles are generally classified into two categories:
inflammation of structures in the joint, or tears of the tendons and muscles.
Acute Rotator Cuff Tears
Acute tears of the rotator cuff usually result from a quick, sudden, and powerful movement such as following through on a baseball pitch or a sudden thrust with a canoe paddle.
Symptoms of an acute rotator cuff tear may include:
- A sudden tearing/ripping sensation on the shoulder followed by severe pain
- Pinpoint tenderness over the point of rupture
- Limited movement due to pain or spasms
- Severe pain for a few days
- In severe cases, inability to raise arms outwards without help.
Chronic Rotator Cuff Tears
Chronic rotator cuff tears develop over an extended period of time and may be caused by repetitive motion or overuse. These tears usually occur at or near the tendon due to the tendon rubbing the overlying bone, causing fraying of the tendon and potentially a larger tear if untreated. Chronic tears tend to occur on the dominant side, and are more common in people aged 40 years or older.
Symptoms of a chronic rotator cuff tear may include:
- Pain is worse at night; may affect sleeping
- Pain becomes gradually stronger while arm becomes gradually weaker
- Arm is eventually unable to be lifted outwards without help