A 16 year old athlete boy was diagnosed with an isolated avulsion fracture of the lesser tubercle of the humerus. It is caused by the forceful contraction of which of the following muscles ?
High-Yield Explanation
The subscapularis muscle is inseed on the lesser tubercle of the humerus. Forceful contraction of subscapularis muscle to resist the abduction and external rotation of the shoulder may cause an isolated avulsion fracture of lesser trochanter. Ref : Gray's Anatomy The Anatomical Basics of Clinical Practice 41e pg 806.