Author: Dr Peter de Souza
Last modified: 23 November 2023

The pectoralis minor muscle is a thin triangular shaped muscle which lies deep to the much larger and more powerful pectoralis major muscle.

Origin

  • Anteromedial surfaces of ribs 3-5

Insertion

  • Coracoid process of scapula

Action

  • Depresses shoulder
  • Protracts scapula
  • Stabilise scapula against the chest wall

Innervation

  • Medial pectoral nerves

Blood Supply

  • Clavicular branch of thoracoacromial trunk