W7 (OIA’s) All Lateral Trunk Anterior

Pectoralis major (origin)

Clavicle, sternum and costal cartilages

Pectoralis minor (origin)

Ribs 3-5

External Intercostals (origin)

Inferior border of rib above

Internal intercostals (origin)

Superior border of rib below

Transversus thoracis (origin)

Body of sternum and xiphoid process

Serratus anterior (origin)

Ribs 1-9

Pectoralis major (insertion)

Lateral lip of intertubercular groove of humerus

Pectoralis minor (insertion)

Coracoid process of scapula

External intercostals (insertion)

Superior border of rib below

Internal intercostals (insertion)

Inferior border of rib above

Transversus thoracis (insertion)

Internal ribs 2-6

Serratus anterior (insertion)

Vertebral (medial) border of the scapula

Pectoralis major (action)

Adduction of arm

Pectoralis minor (action)

Fixates scapula

External intercostals (action)

Elevation of ribs for inspiration

Internal intercostals (action)

Depression of ribs for expiration

Transversus thoracis (action)

Depression of ribs for expiration

Serratus anterior (action)

Abducts scapula; elevates ribs