Rotator cuff injuries may be grouped into two major areas: traumatic injuries and degenerative injuries. While traumatic injuries are one-time events—often unforeseeable accidents—degeneration occurs over time.
People with degenerative rotator cuff injuries tend to have one or more of the following risk factors:
- Overuse. Degenerative rotator cuff injuries are more common in people who engage in repetitive overhead shoulder motions, such as hammering, painting, swimming, playing tennis, or pitching a baseball.
- Shoulder arthritis. People with shoulder arthritis are more likely to develop shoulder instability, muscle weakness, and bony cysts, called osteophytes. All of these factors can put more stress on the rotator cuff, making it more prone to injury.
- Older age. Degenerative rotator cuff injuries tend to occur in people over 401 and become increasingly more common as people age. Experts estimate that 15% to 30% or more of people over age 70 have rotator cuff tears.2,3 These injuries do not always cause symptoms and may not require treatment.
While older age is a risk factor, rotator cuff injuries are becoming more common in younger people as the emphasis on intense training and year-round sports for young people has increased.4