Rotator cuff tendonitis is one of the most common conditions affecting the shoulder. It is generally caused by overuse or overload.
Overuse or overdoing shoulder exercise can happen in sports like swimming or during throwing sports, where the repetitive motion
of the arm causes irritation to the cuff. Tensile overload is when the shoulder experiences a sudden pull or jerk and can
lead to rotator cuff tendonitis. An example of tensile overload to the shoulder is when a person is walking a dog and the dog pulls
hard on the leash, resulting in a sudden jerk or pull to the shoulder. The rotator cuff muscles are four very small, fragile muscles named supraspinatus, infraspinatus,
subscapularis and teres minor. The purpose of these four muscles is to help the arm attach and move properly in the shoulder socket. Of the four muscles, supraspinatus is the
most important and the most commonly injured.