Teres Major vs. Teres Minor Confusion

Meg Trahan

When the arms fall forward during an overhead squat - how is the teres major short and overactive, but then the rotator cuff is listed as underactive?  Is it more specifically one of the muscles that can be tight in the rotator cuff, but the rotator cuff as a whole underactive?

Brent Brookbush

Thank you for being brave enough to post this…  This is a trap that everyone learning anatomy and kinesiology has fallen into.  Your confusion has nothing to do with the overhead squat assessment or the solutions tables. The real question is “what is the difference between the “teres major and teres minor.”

The teres MAJOR has an origin at the lower third of the lateral border of the scapula and inserts into the bicipital groove on the front side of the humerus - very close to the insertion of the latissimus dorsi.  It will do the same joint actions the latissimus dorsi will do at the shoulder.  It is often termed the "lats little brother."  The lats and teres major are both internal rotators and extensors of the humerus, hence they are tight if the arms fall forward during an overhead squat assessment - indicating upper-body dysfunction.

The teres MINOR is a muscle of the rotator cuff and although it originates just above the teres major on the lateral border of the scapular it wraps around the posterior aspect of the humeral head and inserts into the lower portion of the greater tubercle of the humerus.   The teres minor, along with the infraspinatus, does external rotation.  When the