The rotator cuff tendons, especially Supraspinatus, is one of those spots in the body that is set up to fail. Why you ask? Well the tendon is located in a “watershed” area between two bones, the head of the Humerus below and the Acromion above with not great blood supply. Every time the arm is elevated, the blood supply is further impacted by the Humerus pinching against the Acromian. In people who have a “down sloping” Acromion, the pressure arrives on the tendon earlier than usual, and over time the tendon weakens in the area with poor blood supply, and the tendon can tear when loaded. I have seen so many people with surprising stories about how they ended up tearing the Supraspinatis tendon, from being pulled behind a boat while water skiing on one hand to playing basketball and catching an arm while shooting on the other.
A tear in the RC Cuff can be full thickness or partial thickness. A partial thickness tear can produce some shoulder pain, usually out on the lateral side of the shoulder, and it can “hide” being mostly pain free, or produce an achy shoulder from time to time. I had a partial thickness tear in my left shoulder from an gymnastics injury in high school when I was 17 years old, and it came and went for years until I tore it again playing basketball when I was 38 years old. At that point the tear was deep enough to bother me all the time, and especially at night. Night time shoulder pain is one of those “red flags” that implies that further testing is appropriate. If you are having hard time lifting things, opening your car door, and coping with unexpected movements, its time to see you doctor!
The good news is that an accromioplasty (shaving the underside of the acromion) and a rotator cuff repair (shaving off the torn part) is a quick recovery, but the full thickness tear is more work. Here is a good full thickness surgery repair blog
Even after the full thickness repair, a full recovery is completely possible…you can read more about recovering from injuries on my website here.