Back Muscles Flashcards
Upper Trapezius Insertion and Origin
Origin:
*External occipital protuberance and superior nuchal line of occipital bone
* Ligamentum nuchae
* Spinous process of C7
Insertion:
* Posterior aspect of lateral 1/3rd of clavicle
* Acromion of scapula
Middle Trapezius Insertion and Origin
Origin:
* Spinous processes of C7-T4
Insertion:
* Acromion of scapula
* Medial ½ of spine of scapula
Lower Trapezius Insertion and Origin
Origin:
* Spinous processes of T5-T12
Insertion:
* Medial ½ of spine of scapula
The action of Upper, Middle, and Lower Trap
Upper:
* Elevation of scapula
* Retraction of scapula
* Upward rotation of scapula
* Lateral flexion of neck and head
* Extension of neck and head
Middle:
* Retraction of scapula
Lower:
* Depression of scapula
* Retraction of scapula
* Upward rotation of scapula
Innervation of Trapezius
Cranial nerve XI (accessory nerve)
Latissimus Dorsi Origin and Insertion
Origin:
* Spinous processes of T7-T12
* Ribs 9 to 12
* Thoracolumbar fascia
* Iliac crest
Insertion:
* Floor of intertubercular sulcus (groove) of humerus
Action and innervation of Latissimus Dorsi
- Adduction of humerus
- Medial rotation of humerus
- Extension of humerus
Thoracodorsal nerve
Rhomboid Maj. and Min. Insertion and Origin
Maj
Origin:
* Lower part of ligamentum nuchae
* Spinous processes of C7-T1
Insertion:
* Medial border of scapula adjacent to spine of scapula
Min
Origin:
* Spinous processes of T2-T5
Insertion:
* Medial border of scapula inferior to spine of scapula
Innervation of Rhomboid Maj & Minor
Dorsal scapular nerve
Levator scapula Origin and Insertion
Origin:
* Transverse processes of C1-C2
* Posterior tubercles of transverse processes of C3-C4
Insertion:
* Superior angle of scapula
* Medial border of scapula superior to spine of scapula
Action and Innervation of Levator scapula
Unilateral action:
* Elevation of scapula
* Downward rotation of scapula
* Lateral flexion of neck (ipsilateral)
Bilateral action:
* Extension of neck
Anterior rami of cervical spinal nerves
* Dorsal scapular nerve
Serratus Posterior Sup. & Inf. Origin and Insertion
Sup:
Origin:
* Ligamentum nuchae
* Spinous processes of C7-T3
* Supraspinous ligaments
Insertion:
* External surfaces of 2nd to 5th ribs
Inf:
Origin:
* Spinous processes of T11-L2
* Supraspinous ligaments
Insertion:
* External surfaces of 9th to 12th ribs
Action and innervation of Serratus Posterior Sup. & Inf.
Sup.:
* Elevation of ribs #2-5 at costovertebral joints (aids in respiration)
Inf:
Depression of ribs #9-12 at their costovertebral joints (aids in respiration)
Anterior rami of thoracic spinal nerves
Splenius Origin and Insertion, Innervation
Origin:
* Ligamentum nuchae
* Spinous processes of C7-T3 or T4 vertebrae
Insertion:
* Splenius capitis: fibers run superolaterally to mastoid process of temporal bone and lateral third of superior nuchal line of occipital bone
* Splenius cervicis: tubercles of transverse processes of C1-3 or C4 vertebrae
Posterior rami of cervical nerves
erector spinae: from lateral to medial
I Love Shamay
Iliocostalis
longissimus
Spinalis
erector spinae: Origin and insertion, innervation
Origin:
* Broad tendon from posterior part of iliac crest, posterior surface of sacrum, sacro-iliac ligaments, sacral and inferior lumbar spinous processes and supraspinous ligament
Insertion:
* Iliocostalis (lumborum, thoracis, and cervicis): fibers run superiorly to angels of lower ribs and cervical transverse processes
- Longissimus (thoracic, cervicis and capitis): fibers run superiorly to ribs between tubercles and angles to transverse processes in thoracic and cervical regions and to mastoid process of temporal bone.
- Spinalis (thoracis, cervicis and capitis): fibers run superiorly to spinous processes in upper thoracic region and to cranium.
Posterior rami of spinal nerves
Semispinalis OI
Thoracis
Cervacis
Capitis
Origin:
* Arises from transverse processes of C4-T10 vertebrae
Insertion:
* Fibers run superomedially to occipital bone and spinous processes in upper thoracic and cervical regions, spanning 4-6 segments.
Multifidus OI
Origin:
* Posterior superior iliac spine
* Dorsal surface of sacrum
* Mammillary processes of lumbar vertebrae
* All transverse processes of thoracic vertebrae
* Articular processes of C4-C7
Insertion:
* Span between 2-4 vertebrae to insert into spinous processes of lumbar, thoracic, and cervical vertebrae
-present throughout vertebral column
-best developed in the lumbar region
Rotatores IO
Origin:
* Arise from transverse processes of vertebrae
Insertion:
* Brevis: laminae and spinous processes of thoracic vertebrae 1 vertebral segment above
* Longus: laminae and spinous processes of thoracic vertebrae 2 vertebral segments above
- present throughout vertebral column
- best developed in the thoracic region
Innervation of transversospinales
Posterior rami of spinal nerves
Minor Deep Layer of intrinsic back muscles
interspinales
Best developed in cervical and lumbar regions – sometimes absent in thoracic region
Intertransversarii
Intertransversarii muscles are present throughout vertebral column
Levatores costarum
Interspinales OI
Origin:
* Superior aspect of spinous processes along vertebral column
Insertion:
* Inferior aspect of adjacent spinous processes along vertebral column
Intertransversarii IO
Origin:
* Transverse processes of cervical, thoracic and lumbar vertebrae
Insertion:
* Transverse processes of vertebra superior to origin
Levatores costarum IO
Origin:
* Transverse processes of C7 and T1-11 vertebrae
Insertion:
* Superior border of rib 1 level below origin
Action of Interspinales, Intertransversarii, levatores costarum
Interspinales, Intertransversarii:
Stabilization of vertebral column
levatores costarum
Unilateral action:
* Side flexion of vertebral column (ipsilateral)
* Rotation of trunk (contralateral)
Bilateral action:
* Elevation of ribs during inhalation
Innervation of Interspinales, Intertransversarii, levatores costarum
Interspinales, evatores costarum:
posterior rami of spinal nerve
Intertransversarii:
anterior and posterior rami of spinal nerves
