Pectoralis major

Origin

Clavicular head: medial half of clavicle.

Sternal head: sternum, cartilages of upper six ribs.

Pectoralis major

Insertion

Lateral lip of bicipital groove of humerus.

Pectoralis major

Action

Adduction, horizontal adduction and medial rotation of humerus.

The pectoralis major also assists in other humeral movement.

Pectoralis major

Palpation

Along anterior border of axilla.

Pectoralis major

Innervation

Clavicular head: lateral pectoral nerve (C5, 6, 7).

Sternal head:  medial pectoral nerve (C8, T1)

Pectoralis minor

Origin

Anterior 3, 4, 5 ribs.

Pectoralis minor

Insertion

Coracoid process of scapula

Pectoralis minor

Action

Protraction (abducts) depression, downward ratation of scapula

Pectoralis minor

Palpation

Difficult to palpate.

Pectoralis minor

Innervation

Medial pectoral nerve (C8, T1)

Pectoralis minor

The pectoralis minor forms a bridge over the brachial plexus of vessels of the arm.

Subclavius

Origin

First Rib.

Subclavius

Insertion

Inferior shaft of clavicle

Subclavius

Action

Stabilises the clavicle

Subclavius

Palpation

Cannot palpate.

Subclavius

Innervation

Nerve to subclavius (C5, 6)