Posterior Thoracic Muscles

• Trapezius


  most superficial muscle of the posterior thorax

  flat + triangular

  upper fibres run inferiorly to scapula

  middle fibres run horiz to scapula

  lower fibres run superiorly to scapula

  
• Trapezius - Origin & Insertion


  origin - occipital bone, spinous processes of C7 + all thoracic vertebrae

  insertion - a continous insertion along acromion + spine of scapula + lateral 3rd of clavicle
• Trapezius - Action


  stabilises, elevates, retracts + rotates scapula

  middle fibres retract (adduct) scapula

  superior fibres elevate scapula (shrugging) + help extend head w scapula fixed

  interior fibres depress scapula + shoulder
• Levator Scapulae


  located at back + side of necklocated at back + side of necklocated at back + side of necklocated at back + side of neck

  deep to trapezius

  origin - transverse processes of C1-C4

  insertion - medial border of scapula, superior to spine

  
• Levator Scapulae - Action


  elevates + adducts scapula in synergy w superior fibres of trapezius

  tilts glenoid cavity downward when scapula is fixed

  flexes neck to same side
• Rhomboids


  2 roughly diamond shaped muscles lying deep to trapezius + inferior to levator scapulae

  rhomboid minor = more superior muscle