Sports medicine physicians have raised concerns for years about pitching injuries affecting developing bones in high school athletes, and new research provides firm evidence that those concerns are justified.

The study, published Tuesday in the journal Radiology, found that high school and college-age baseball pitchers who threw more than 100 pitches a week were at increased risk for an injury that caused incomplete fusion and tenderness at the acromion. That’s the structure at the top of the shoulder formed from four bones that fuse during the teenage years.

“Over the years, young pitchers presented to us with shoulder pain, where we just saw fluid on the MRI, and we didn’t know what it meant,” said Dr. Johannes Roedl, a radiologist at Thomas Jefferson University in Philadelphia. He and his team reviewed MRI scans performed years later on 61 patients who had overuse injuries and found that more than 80 percent wound up with incomplete fusion in the acromion. By comparison, that problem was not found in pitchers who had shoulder pain caused by other problems.


“The take-home message here is that pitchers can avoid this overuse injury by making sure to not go above 100 pitches per week,” Roedl said. “It is important to limit stress to the growing bones to allow them to develop normally.” D.K.