Trapezius

Trapezius
The trapezius muscle (pl.: trapezii) is a surface muscle of back, shown in red above and below.
Details
OriginMedial one-third of superior nuchal line, external occipital protuberance, spinous processes of vertebrae C7-T12, Nuchal ligament[1]
InsertionPosterior border of the lateral one-third of the clavicle, acromion process, and spine of scapula
ArterySuperficial branch of transverse cervical artery or superficial cervical artery [2]
NerveAccessory nerve (motor)
cervical spinal nerves C3 and C4 (motor and sensation)[3]
ActionsRotation, retraction, elevation, and depression of scapula
AntagonistSerratus anterior muscle, latissimus dorsi, pectoralis major
Identifiers
Latinmusculus trapezius
TA98A04.3.01.001
TA22226
FMA9626
Anatomical terms of muscle

The trapezius[4] is a large paired trapezoid-shaped surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the spine and laterally to the spine of the scapula. It moves the scapula and supports the arm.

The trapezius has three functional parts:

  • an upper (descending) part which supports the weight of the arm;
  • a middle region (transverse), which retracts the scapula; and
  • a lower (ascending) part which medially rotates and depresses the scapula.
  1. ^ Rockwood, Charles A. (January 1, 2009). The Shoulder. ISBN 978-1416034278.
  2. ^ "Tufts". Archived from the original on April 22, 2003. Retrieved December 11, 2007.
  3. ^ Dalley, Arthur F.; Moore, Keith L.; Agur, Anne M.R. (2010). Clinically oriented anatomy (6th [International] ed.). Philadelphia [etc.]: Lippincott Williams & Wilkins, Wolters Kluwer. p. 700. ISBN 978-1-60547-652-0.
  4. ^ Lajtai, Georg; Applegate, Gregory; Snyder, Stephen J.; Aitzetmüller, Gernot; Gerber, Christian (March 11, 2003). "trapezoid"&pg=PA89 Shoulder Arthroscopy and MRI Techniques: 20 Tables. ISBN 9783540431121.