Chest Muscles

There are five important chest muscles to be familiar with. The ones we will learn are:

Diaphragm

Pectoralis Minor

Serratus Anterior

Internal Intercostals

External Intercostals

Below are the study aids for massage therapy students.

Diaphragm

Insertion is central tendon.

Action--expands thoracic cavity during inspiration (breathing in).

Diaphragm is the prime mover of inspiration.

Pectoralis Minor

Insertion is coracoid process of scapula.

Actions--assists in forced inspiration, depresses scapula, protracts scapula, downwardly rotates scapula.

Along with the Scalenes, Pectoralis Minor is also known as the neurovascular entrappers.

Serratus Anterior

Insertion is anterior medial border of scapula.

Actions--upwardly rotates scapula and protracts scapula.

Serratus Anterior with Triceps Brachii is also known as the boxer's muscle. They enable a boxer to give a straight punch.

Paralysis of this muscle produces winged scapula. This makes it impossible to lift the arm laterally above 90 degrees.

Internal Intercostalis

Insertion is inferior border of rib.

Actions--maintains intercostal spaces and depresses rib cage during exhaling.

External Intercostalis

Insertion is superior border of rib.

Actions--maintains intercostal spaces and elevates rib cage during inhalation.

Return from Chest Muscles to Muscles