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Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Injuries to muscle-tendon units are called strains and are classified by the amount of damage to the muscle or tendon fibers. Grade I strains involve stretching of the fibers without any tears. Grade II injuries involve partial muscle or tendon tearing, and grade III injuries are defined as a complete tear of a muscle or tendon.

The muscles and tendons in the rotator cuff group may be damaged in a variety of ways. Damage can occur from an acute injury (for example from a fall or accident), from chronic overuse (like throwing a ball or lifting), or from gradual degeneration of the muscle and tendon that can occur with aging.

• This injury can develop from sudden powerful raising of the arm against resistance or in an attempt to cushion a fall (for example, heavy lifting or a fall on the shoulder).



• The injury requires a significant amount of force if person is younger than 30 years of age.

• Found among people in occupations or sports requiring excessive overhead activity (examples, painters, baseball pitchers)



• The chronic injuries may be a result of a previous acute injury that has caused a structural problem within the shoulder and affected the rotator cuff anatomy or function (for example, bone spurs that impinge upon a muscle or tendon causing inflammation).



• Repetitive trauma to the muscle by everyday movement of the shoulder

• Degeneration (wearing out) of the muscles with age



• This usually occurs where the tendon attaches to bone. The area has poor blood supply and a mild injury may take a long time to heal and potentially lead to a secondary tear.

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