Trapezius - Muscle Physiology & Functional Anatomy

 

Anatomy

 

Origin:

  • Upper Fibers

    • Medial third of the superior nuchal line and external occipital protuberance of the skull

     

  • Middle Fibers

    • Spinous processes of vertebrae T1-T3 & C7

     

  • Lower Fibers

    • Spinous processes of vertebrae T4-T12

Insertion:

  • Upper Fibers

    • Lateral third of the posterior clavicle

     

  • Middle Fibers

    • Medial border of acromium process

     

  • Lower Fibers

    • Inferior middle spine of scapula



Major Artery:

  • Transverse cervical artery

 

Neural Innervation:

  • Accessory Nerve (motor function)

  • Cervical spinal nerves C3 & C4 (motor & sensory)

 

Trigger Points:

Trigger Points of the TrapTrapezius Trigger Points

 

Physiology

 

Concentric Functions:

  • Upper Fibers

    • Elevation of the scapula

    • Extension of the cervical spine

    • Extension, lateral flexion & rotation of the atlantoccipital & antlantoaxial neck

     

  • Middle Fibers

    • Adduction (rectaction), upward rotation and elevation of the scapula

     

  • Lower Fibers

    • Upward rotation, adduction (retraction) & depression of the scapula

    • Weak extensor of the thoracic spine

 

Eccentric Functions:

  • Upper Fibers

    • Decelerates cervical flexion, lateral flexion & rotation

  • Middle Fibers

    • Decelerates scapular abduction (protraction) & upward rotation

     

  • Lower Fibers

    • Decelerates scapular elevation

 

 

Isometric Function:

  • Upper Fibers

    • Assists in providing dynamic stability to the cervical spine and shoulder complex

     

  • Middle Fibers

    • Assists in dynamically stabilizing the scapula during functional movements

     

  • Lower Fibers

    • Assists in dynamically stabilizing the scapula

 

 

Related Muscles

Antagonists

 

Exercises:

 

 


More Images of the Trapezius Muscle

 

Trapezius


More Information about the Trapezius Muscle

The trapezius muscle is named because of its trapezoidal shape.

 

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