Serratus anterior

A.Prof Frank Gaillard and Dr Henry Knipe et al.

Serratus anterior arises from the lateral chest wall as eight interdigitations of muscle that run posteriorly around the chest wall, under the scapula to insert onto the medial scapula. 

  • origin: anterolateral ribs 1-8 or 1-9
  • insertion: medial border of the scapula
  • innervation: long thoracic nerve
  • action:
    • draws scapula anteriorly against the chest wall
    • when scapula is fixed, assists in respiration

Injury to the long thoracic nerve during axillary surgery causes winging of the scapula as serratus anterior no longer holds the scapula against the chest wall. 

  • attachment to the tenth rib
  • absence of attachments to the first rib
  • union with fibres of the insertion of the levator scapulae, external intercostals or external oblique
Anatomy: Upper limb
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Article information

rID: 23255
Section: Anatomy
Synonyms or Alternate Spellings:
  • Serratus anterior muscle

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