Dr. BradyShoulder pain can affect every action of the day, from combing your hair and getting dressed, to getting in and out of the car and going to sleep at night. The rotator cuff is the set of four muscles that come together at the top of the shoulder, attached to the bones by tendons. If one of those tendons develops a tear, which is common in people over the age of 50, everyday activities can become very painful.“A rotator cuff injury can be caused by all kinds of things, like bone spurs or injuries. People develop rotator cuff tears over time, or sometimes from a single event,” said Dr. Paul Brady, an orthopedic surgeon at Parkwest Medical Center.