Extrinsic Back Musculature Flashcards
(35 cards)
Extrinsic musculature consists of ______ and _____ layers of the back
Extrinsic musculature consists of superficial and intermediate layers of the back
Extrinsic musculature innervated by ______ and develop (ventrally/dorsally)
Extrinsic musculature innervated by ventral rami (except trapezius) and develop ventrally
Superficial Extrinsic Back Muscles (Axio-Appendicular Musculature): List the (5)
- Trapezius
- Latissimus dorsi
- Levator Scapulae
- Rhomboid minor
- Rhomboid major
Identify this muscle
Trapezius
Insertion:
Action:
Innervation:
Trapezius
Insertion: acromion and spine of the
scapula
Action:
o Upper fibers (descending): Elevate scapula
o Middle fibers: Retract scapula
o Lower fibers (ascending): Depress scapula
o Upper + Lower: superior rotation of shoulder joint (glenohumeral joint)
Innervation: Spinal accessory nerve (Cranial Nerve XI)
Trapezius action
- Descending: elevation of scapula
- Middle: retracts scapula
- Ascending: depresses scapula
- Descending + ascending: superior rotation of shoulder joint (glenohumeral joint)
Trapezius innervation
CN XI: Spinal Accessory Nerve.
Identify this muscle
Latissimus Dorsi
Origin:
Insertion:
Action:
Innervation:
Latissimus Dorsi
Origin: Spinous processes of T6-T12, thoracolumbar fascia, iliac crest
Insertion: Intertubercular sulcus of the humerus
Action: Arm extension, adduction, and medial rotation of the humerus at the glenohumeral joint
Innervation: Thoracodorsal nerve (C6-C8) ventral rami
Latissimus dorsi action
extends, adducts, and medially rotates the humerus at the glenohumeral joint
Lastissimus dorsi innervation
Thoracodorsal nerve
Levator Scapulae
Origin:
Insertion:
Action:
Innervation:
Origin: Transverse processes of C1-C4
Insertion: Medial border of the scapula (superior to the root of scapular spine)
Action: Elevates the scapula, assists in downward rotation;
Innervation: Dorsal scapular nerve (C5) ventral rami
Identify this muscle
Levator scapulae
Levator scapulae action
Elevates scapula rotates
glenoid cavity inferiorly
Levator scapulae innervation
Dorsal scapular nerve (C5) of ventral rami
Origin:
Insertion:
Action:
Innervation:
Levator Scapulae
Origin: Transverse processes of C1-C4
Insertion: Medial border of the scapula (superior to the root of scapular spine)
Action: Elevates scapula rotates
glenoid cavity inferiorly
Innervation: Dorsal scapular nerve (C5) ventral rami
Origin:
Insertion:
Action:
Innervation:
Rhomboid Minor
Origin: Spinous processes of C7-T1 + nuchal ligament
Insertion: Medial end of scapula, at the level of the spine
Action: Retracts and stabilizes the scapula to the thoracic wall; inferior rotation of the glenohumeral joint
Innervation: Dorsal scapular nerve (C5) ventral rami
Identify this muscle
Rhomboid minor
Rhomboid minor and major innervation
Dorsal scapular nerve (C5) ventral rami
scapula translated laterally and downwardly rotated.
Trapezius palsy: “drooped shoulder”
scapula translated laterally and downwardly rotated.
Describe Trapezius palsy treatment:
surgically with muscle transfers of levator scapulae and rhomboids
scapula moved laterally and lower medial border and inferior angle are raised
RHOMBOID PALSY:
scapula moved laterally and lower medial border and inferior angle are raised
TREATMENT FOR?
TRAPEZIUS PALSY TREATMENT: levator scapulae is moved to the scapular spine, rhomboids moved to the posterior inferior scapula.
Nerves of the back:
- Spinal Accessory Nerve - CN XI
- Dorsal scapular nerve (C5)
- Thoracodorsal nerve (C6-C8)
- Cutaneous branches of posterior rami
