Overview
The rotator cuff is made up of four muscles that help move and stabilize the shoulder joint. damage to any one of the four muscle or their ligaments that attach muscle to bone can occur. When the rotator cuff is damaged, a variety of issues arise such as: pain and spasm limit the range of motion in the shoulder, the muscles do not make the small adjustments within the joint to allow the humeral head to move smoothly, fluid accumulation within the joint due to inflammation limits movement, arthritis and calcium deposits that form over time limit range of motion.
Causes
Acute injury
Chronic overuse
Aging (degeneration)
Chronic tear
Tendonitis
Symptoms
Sudden tearing sensation followed by sever pain shooting from the upper shoulder area down the arm toward the elbow
Decreased range of motion
Muscle spasm
Inability abduct (raise out to the side) the arm
Pain that is worse at night
Gradual weakness and decreased shoulder motion
Deep ache in the shoulder also felt on the outside upper arm over the deltoid muscle
Diagnosis
Physical examination and medical history consultation
X-rays
MRI
Arthrograph
Ultrasound
Treatment
Rest
Application of ice
Immobilization
Non-steroidal anti-inflammatory medications
Physical therapy
Steroid injections
Surgery
Source: http://www.emedicinehealth.com/rotator_cuff_injury/article_em.htm