What is it?: You rotator cuff is actually four muscles in your shoulder. The tendons for these muscles come together and form a common “cuff” that wraps around the head of your
humerus and keeps it tight in the shoulder socket. While the primary motion of these muscles is internal and external rotation (like in throwing, arm wrestling, and tucking your shirt in in the back) the primary responsibility of these muscles is to control the movement of the humerus (arm bone) on the shoulder blade. When things are firing 100% normal you have a healthy, pain-free shoulder. When the mechanics of the shoulder are off a little bit (most of the time due to either a range of motion deficit or muscle insufficiency) this can result in a microtrauma to these tendons as they’re being used. Repeat this for long enough (i.e. repetitive movements or even just daily wear-and-tear) and you can develop inflammation in this area. As I’ve mentioned previously, anytime you hear the suffix “-itis” on the end of a word it’s indicative of inflammation… “tendonitis” is therefore an inflamed tendon.
Rotator cuff weakness: In my opinion this is probably the #1 cause of shoulder pain; especially in the world of health and fitness. It’s been my experience that lots of us spend a lot of
time on the “look good, feel good” muscles and exercises including bench press, military press, deltoid raises, etc. However most of us neglect the very most important muscle in the whole shoulder complex – the rotator cuff. If these muscles aren’t strong enough to support your shoulder through these motions and stresses are placed on areas that are too weak then you will develop pain in these areas. Rotator cuff weakness is (in my opinion) the most likely cause of your shoulder pain.
By Jared Beckstrand