Infraspinatus – Is one of the Rotator Cuff muscles, It externally rotates the shoulder at the Glenohumeral joint. It provides stability to the shoulder by bringing the Humerus toward to Glenoid Fossa of the Scapula.

The nerve to the muscle is the Suprascapular nerve which branches out from C5 C6

Its synergists are Teres Minor and the Deltoid

Below is a simple Theraband exercise which will help to strengthen the Infraspinatus