Infraspinatus

·         Connects from the medial border of the scapula, running under the scapular spine to the greater tuberosity of the humerus.

·         Contraction allows the arm to rotate externally.

·         The other rotator cuff muscle which assists in external rotation is the teres minor.

·         The infraspinatus is the 2^nd most commonly injured rotator cuff muscle.

Testing:

·         Bend the elbows to 90 degrees

·         Slightly abduct their shoulder, roughly 30 degrees, while keeping both elbows bent at 90 degrees

·         Place your hands on the outside of their forearms.

·         Have the patient push their arms outward (externally rotate) while you resist.

·         Tears in the muscle will cause weakness and/or pain.

The following website has nice photos of all of the tests for the various rotator cuffs:

http://meded.ucsd.edu/clinicalmed/joints2.htm

Linda Regan, MD FACEP

Program Director, Emergency Medicine Residency

Johns Hopkins Medical Institutions