Intrinsic Back Muscles Flashcards
Insertion of the Splenius Capitis
- Superolaterally to the mastoid process of the temporal bone
- Lateral 1/3 of the superior nuchal line of the occipital bone
Common origins of Splenius Capitis and Cervicis
- Nuchal ligament
2. Spinous process of C7-T6
Insertion of the Splenius Cervicis
Tubercles of transverse processes of C1-C3 or C4 vertebrae
Innervation of the Splenius Capitis
Posterior rami of spinal nerves
Main action of Splenius when acting alone
Laterally flex neck and rotate head ipsilaterally
Main action of Splenius when acting together
Extend head and neck
Origin of Semispinalis (Capitis, Cervicis, and Thoracis)
Transverse processes of C4-T10
Insertion of the Semispinalis (Capitis, Cervicis, Thoracis)
- Occipital bone
2. Spinous processes of the upper thoracic and cervical region spanning 4-6 segments
Nerve supply of Semispinalis (Capitis, Cervicis, and Thoracis)
Posterior rami of spinal nerves
Main actions of Semispinalis (Capitis, Cervicis, and Thoracis)
Extends head, thoracic, and cervical regions of the vertebral column and rotates them contralaterally
Origin of the Multifidus
- Posterior sacrum
- Posterior Superior Iliac Spine of ilium
- Aponeurosis of erector spinae
- Sacro-iliac ligaments
- Mammillary processes of lumbar vertebrae
- Transverse processes of thoracic vertebrae
- Articular Processes of C4-C7
Insertion of the Multifidus
- Thickest in the lumbar region
2. Entire length of spinous processes 2-4 segments superior to the origin
Nerve supply of the Multifidus
Posterior spinal rami of spinal nerves
Main actions of the Multifidus
- Unilateral contraction rotates to contralateral side
2. Stabilizes vertebrae during local movements of vertebral column
Common origin of Rotatores (Longus and Brevis)
Transverse processes of vertebrae
Insertion of Rotatore Brevis
Junction of lamina and transverse process or spinous process immediately to vertebrae of origin
Insertion of Rotatore Longus
Junction of lamina and transverse process or spinous process 2 segments superior to vertebra of origin
Nerve supply of Rotatores (Longus and Brevis)
Posterior rami of spinal nerves
Main action of Rotatores (Longus and Brevis)
- Functions as organs of proprioception
- Stabilize vertebrae
- Assist with local extension
- Rotatory movements of vertebral column
