A new study has shown for the first time the effect of rotator cuff tendon overuse, or tendinopathy, on surrounding tissues.
The rotator cuff is a group of four muscles and tendons in the shoulder, connecting the upper arm (humerus) to the shoulder blade (scapula). Overuse is among the major causes of shoulder pain and discomfort in athletes, manual workers, older people, and those who use a repetitive overhead motion in daily activities.
Left untreated, tendinopathy can lead to full or partial rotator cuff tendon rupture, which may require surgery.
For the study, researchers at the W.H. Coulter Department of Biomedical Engineering at Georgia Institute of Technology & Emory University School of Medicine used rats in order to better understand the time course of tendon protease activity, as well as determine the effects of 10 weeks of overuse on humeral head articular cartilage.
They observed both degeneration of the shoulder tendon and osteoarthritis-like changes to neighbouring cartilage.
According to the researchers, their work may help clinicians determine the optimal type and timing of treatment for tendon overuse injuries to reduce further damage.
“This is an exciting finding as it is the first demonstration that overuse injuries may impact more than just the shoulder tendons. Thus, this study may provide motivation for further research in humans to better protect the shoulder joint as a whole from these types of injuries,” said senior study author Dr Johnna Temenoff.
The results of the study have been published in the Journal of Orthopaedic Research.