Back muscles

While working on neck muscles. Let's remember the back muscles.

Great round muscle (TERE MAJOR, TMA)
Little round muscle (TERES MINOR, TMI)
Infraspinatus muscle (IS)

These are the main muscle that is responsible for turning and rotating the arm. The adduct and medially rotates the arm, extends a flexed arm. TMA and TMI both adduct the arm but are antagonists for rotation of the humerus. TMA rotates it towards the body, TMI rotates it to the side. Infraspinatus muscle (IS) rotates the arm and stabilizes the shoulder joint from behind by holding the head of the humerus in its socket.

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