99% of adults over 40 have shoulder “abnormalities” on an MRI, study finds (Beth Mole, Feb 17, 2026, Ars Technica)
In a study published in JAMA Internal Medicine this week, 99 percent of adults over 40 were found to have at least one abnormality in a rotator cuff on magnetic resonance imaging (MRI). The rotator cuff is the group of muscles and tendons in a shoulder joint that keeps the upper arm bone securely in the shoulder socket—and is often blamed for pain and other symptoms. The trouble is, the vast majority of people in the study had no shoulder problems.
In other words, it’s normal.