Internal Intercostals

Muscle Origin

Superior border of rib below to inferior border of rib above.


Rib – inferior border.

The inferior border of each rib overhangs and forms the costal groove , through which the intercostals vessels and nerves pass.


Contraction draws ribs together for exhalation.anatomy-model-inside-thoracic-052-edited 3

Innervation – Nerve control

Intercostal nerves.

The intercostal nerves are part of the somatic nervous system, and arise from the anterior rami of the thoracic spinal nerves from T1 to T11. The intercostal nerves are distributed chiefly to the thoracic pleura and abdominal peritoneum and differ from the anterior rami of the other spinal nerves in that each pursues an independent course without plexus formation. Wiki


Intercostal arteries.

The intercostal arteries are a group of arteries that supply the area between the ribs (“costae”), called the intercostal space. The highest intercostal artery (supreme intercostal artery or superior intercostal artery) is an artery in the human body that usually gives rise to the first and second posterior intercostal arteries, which supply blood to their corresponding intercostal space. It usually arises from the costocervical trunk, which is a branch of the subclavian artery. Some anatomists may contend that there is no supreme intercostal artery, only a supreme intercostal vein. Wiki

Antagonist muscles

Intercostales interni muscles.

These muscles are between the ribs, lying beneath the external intercostals. During expiration, they pull the ribs downward and inward, decreasing the volume of the chest cavity and contributing to a forced exhalation.

Pictures of Muscles


Trigger Point Referrals


Stretching Description








Additional Resources

Chandler Physical Therapy © 2014 Frontier Theme