L5.5.5.1: Upper Back

• UPPER BACK MUSCLES

  [a] Trapezius

  [b] Infraspinatus

  [c] Teres Major

  [d] Splenius Capitis Cervicis

  [e] Levator Scapulae

  [f] Rhomboideus Minor

  [g] Rhomboideus Major

  
• Trapezius

  ○ Most superficial muscle of the posterior neck and upper trunk

  ○ When seen together, they form a diamond or kite-shaped muscle mass

  ○ Each muscle runs from the occipital bone of the skull down the vertebral column to the end of the thoracic vertebrae, then flare laterally to insert on the scapular spine and clavicle

  ○ Extend the head

  ○ Movements:

  ■ Extend the head

  ■ Elevate, depress, adduct, and stabilize the scapula
• Infraspinatus

  ○ Thick triangular muscle

  ○ Occupies much of the infraspinous fossa of the scapula

  ○ Member of the rotator cuff known as the SITS

  ■ S - Supraspinatus

  ■ I - Infraspinatus

  ■ T - Teres Minor

  ■ S - Subscapularis
• Teres Major

  ○ Thick but flattened rectangular muscle

  ○ Extends from the inferior posterior scapula to the medial lip of the intertubercular groove of the humerus

  ○ Functions synergistically with the latissimus dorsi to extend, adduct, and internally rotate the humerus
• Splenius Capitis Cervicis

  ○ Thick flat muscle at the posterior aspect of the neck arising from the midline and extending superolaterally to the cervical vertebrae

  ○ Comprise the superficial layer of intrinsic back muscles
• Levator Scapulae

  ○ Posterior axio-appendicular muscle

  ○ Connects the upper limb to the vertebral column

  ○ Lies in the posterior triangle of the neck

  ○ Superior aspect is covered by sternocleidomastoid and its inferior part by trapezius
• Rhomboideus Minor

  ○ Cylindrical muscle

  ○ Originates at the ligamentum nuchae and C7 and T1 vertebra

  ○ Inserts at the scapula’s medial border near the base of the spine of the scapula
• Rhomboideus Major

  ○ Quadrangular muscle located inferior to the rhomboid minor

  ○ Originates from the spinous processes of the 2nd to 5th thoracic vertebrae (T2-T5)