Muscle Anatomy of the Shoulder and Arm

Interesting Facts About Shoulder Muscle Anatomy

The Deltoids - these consist of the anterior, lateral and posterior deltoids and are the muscles responsible for shoulder flexion. The anterior deltoids lift the arms above the head and to the front. The main function of the lateral deltoid is shoulder abduction and raises the upper arms upward and to the sides. And the posterior deltoids are responsible for shoulder extension.

The rotator cuff muscles are made up of four muscles and tendons that surround the shoulder, giving it support and allowing its wide range of motion. These are the Infraspinatus, Subscapularis, Supraspinatus and Teres Minor.

The action of the infraspinatus is to provide outward rotation of the shoulder. The subscapularis is responsible for the inward rotation of the the shoulder and upper arm and also plays a key role in overall shoulder stability. The supraspinatus is resonsible for raising the upper arm to the side and away from the side plus again it also plays a key role in shoulder stability. The teres major is responsible for external shoulder rotation, the transverse abduction, transverse extension and posterior shoulder stability.

Interesting Facts About Muscles of the Arm Anatomy

The remaining muscles of the arm are made of the latissimus dorsi, levator scapulae, pectoralis major, pectoralis minor, pronator teres, rhomboids, serratus anterior, subclavius, supinator, teres major and minor and the trapezius muscles. Plus biceps brachii, triceps brachii, coracobrachialis, brachialis, flexor digitorum superficialis, flexor carpi ulnaris, pronator quadratus. These are listings of muscles both at superfical and deep dissection. To see the benefits of excerise and sport on related muscle anatomy please click here.

Anterior superficial dissection

Anterior superficial dissection

Pectoral major muscle

Pectoral major muscle

Biceps brachii muscle

Biceps brachii muscle

 
Brachialis muscle

Brachialis

Flexor digitorum superficialis

Flexor digitorum superficialis

Flexor carpi ulnaris

Flexor carpi ulnaris

 
Flexor carpi radialis

Flexor carpi radialis

Brachioradialis

Brachioradialis

Biceps brachii

Biceps brachii

 
Pronator quadratus

Pronator quadratus