Back Muscles

• General rules of movement

  Bilaterally: extend vertebral column

  Unilaterally: lateral flexion, rotation
• Splenius muscles - capitis and cervicis


  Origin: nuchal ligament, spinous process C7-T3/4

  Insertion: Mastoid process (temporal bone), occipital bone, transverse process of C1-C3/4

  Action:

  Bi- extend neck

  Uni- rotate/laterally flex neck
• Rotatores 


  Origin: transverse process of Vertebrae

  
  

  Insertion: lamina and tranvserse or spinous processes of vertebrae
• Interspinales 


  Origin: spinous processes of vertebrae

  Insertion: spinous process of vertebrae superior to origin

  Action:

  Bi- extend vertebral column

  Uni- laterally flex vertebral column, rotate vertebral column
• Innervation


  Dorsal rami spinal nerve