Some of the causes of rotator cuff tears are degenerative in nature, meaning that they occur over time as a wear and tear phenomenon. This is typically seen in patients who use their arms over their head quite a bit, such as painters or laborers or even people that do cashier work or stock shelves. Typically, this is caused by one of two things: one of which as we age, the blood supply to the rotator cuff muscles in our shoulder becomes less and less. You can imagine blood brings in all the healing potential of the body. It brings in the nutrients and the proteins and all the things that our body needs to heal itself. Unfortunately, as the blood supply goes away, the ability of the body’s innate capacity to heal itself is also diminished and this can result in a tear. Other things that can cause tears are things like bone spurs in the shoulder. We know that as our shoulder, we use it for a number of years, you can develop some bone spurs that form in the shoulder blade. When this happens, every time you raise your arm above your head, that bone spur pushes down on the rotator cuff muscle and over time causes a tear. This is known as external shoulder impingement and is a known cause of rotator cuff tears. I call this the cheese grater effect where the bone spur is essentially pushing on the rotator cuff muscles, and every time you use it is grading it down slowly and slowly to where over time, this leads to a full tear of the shoulder.