How does the rotator cuff get injured?
Your shoulder is made up of three bones: the upper arm bone (humerus), the shoulder blade (scapula), and the collarbone (clavicle). The shoulder is a ball-and-socket joint: The ball, or head, of the upper arm bone fits into a shallow socket in the shoulder blade.
When one or more of the rotator cuff tendons is torn, the tendon becomes partially or completely detached from the humerus.
There are different types of tears.
- Partial tear. This type of tear does not completely detach the tendon from the bone. It is called partial because the tear goes only partially through the thickness of the tendon. The tendon is still attached to the bone, but it is thinned.
- Full-thickness tear. With this type of tear, there is detachment of part of the tendon from the bone.
- When only a small part of the tendon is detached from the bone, it is referred to as a full-thickness incomplete tear.
- When a tendon is completely detached from the bone, it is referred to as a full-thickness complete tear. With a full-thickness complete tear, there is basically a hole in the tendon.