Back Muscles Flashcards
Latissimus dorsi Origin
O: spinous processes of lower thoracic and lumbar vertebrae, iliac crest, sacrum
Trapezius Origin
O: External occipital protuberance, superior nuchal line, ligamentum nuchae, spinous processes of c7 and thoracic vertebrae
Levator scapulae Origin
O: Transverse processes of upper cervical vertebrae
Rhomboid major and minor Origin
O: Spinous processes of lower cervical and upper thoracic vertebrae
Splenius capitis and cervicis Origin
O: Ligamentum nuchae, spinous processes of C7 and upper thoracic vertebrae
Erector Spinae Origin
O: Sacrum, iliac crest, ribs, spinous and transverse processes of vertebrae
Semispinalis capitis Origin
O: Transverse processes of lower cervical and upper thoracic vertebrae
Trapezius Insertion
I: lateral 1/3 of clavicle, acromion, spine of scapula
Trapezius Innervation
I: Accessory nerve
Trapezius Action
A: Superior fibers elevate and laterally rotate scapula; midline fibers retract scapula, inferior fibers depress and laterally rotate scapula
Latissimus Dorsi Insertion
I: Intertubercular groove of humerus
Latissimus Dorsi Innervation
I: Thoracodorsal nerve
Latissimus Dorsi Action
A: Extends, adducts and medially rotates the humerus
Levator Scapulae Insertion
I: Superior angle of scapula
Levator Scapulae Innervation
I: Dorsal scapular nerve
Levator Scapulae Action
A: Elevates scapula
Rhomboid Major and Minor Insertion
I: Medial border of scapula
- Rhomboid minor superior to the spine - Rhomboid major inferior to the spine
Rhomboid Major and Minor Innervation
I: Dorsal scapular nerve
Rhomboid Major and Minor Action
A: Retracts and medially rotates scapula
Splenius Capitis and Cervicis Insertion
I: Capitis - mastoid process and superior nuchal line
Cervicis - transverse processes of upper cervical vertebrae
Splenius Capitis and Cervicis Innervation
I: Dorsal rami of spinal nerves
Splenius Capitis and Cervicis Action
A: Bilaterally - extend the head and neck
Unilaterally - rotate the head to one side.
Erector Spinae Insertion
I: Spinous and transverse processes of vertebrae, ribs, skull
Erector Spinae Innervation
I: Dorsal rami of spinal nerves
Erecter spinae Action
A: Bilaterally - extend head and trunk
Unilaterally - bend trunk laterally
Important in controlling flexion
Semispinalis capitis Insertion
I: Occipital bone near nuchal lines
Semispinalis capitis Innervation
I: Dorsal rami of spinal nerves
Ereector Spinae Action
A: Bilaterally - extend head
Unilaterally - rotate head to one side
