Axio-appendicular Muscles of the shoulder region (Posterior region) MA Flashcards
Rhombodius Minor Muscles (Origin, insertion, innervation, main action)
(Deep muscle)
Origin: Minor: nuchal ligament and the spinous process of the C7-T1 vertebrae.
Insertion: Minor: medial border at the level of the spine
Innervation: Dorsal scapular nerve
Main actions: retracts and downwardly rotates the scapula; fixes scapula to the thoracic wall
Rhombodius Major Muscles (Origin, insertion, innervation, main action)
(Deep Muscle)
Origin: Spinous processes of T2-T5 Vertebrae
Insertion: Medial border of the scapula from the spine to the inferior angle
Innervation: Dorsal scapular nerve
Main action: retracts and downwardly rotates the scapula of the thoracic wall.
Trapezius Muscle (Origin, insertion, innervation, main action)
(Superficial muscle)
Origin: medial 1/3 of the superior nuchal line; external occipital protuberance, nuchal ligament, and spinous process of C7-T12 Vertebrae
Insertion: lateral 1/3 of the clavicle clavicle, acromion, and spine of the scapula
Innervation: Spinal root of accessory nerve (CN XI) (motor); cervical nerves (C3-C4) (pain and proprioception)
Main action: elevates (superior fibers), depresses (inferior fibers), retracts (middle fibers) and upwardly rotates.
Latissimus Dorsi (Origin, insertion, innervation, main action)
(Superficial Muscles)
Origin: Spinous process of inferior 6th thoracic vertebrae, thoracolumbar fascia, iliac crest, and inferior 3-4 ribs
Insertion: floor of the interbercular sulcus of the humerus
Innervation: thoracodorsal nerve (C6-C8)
Main actions: elevates and downwardly rotates the scapula
Levator Scapulae (Origin, insertion, innervation, main action)
(Deep muscle)
Origin: posterior tubercle of the transverse processes of the C1-C4 vertebrae
Insertion: superior part of the medial border of the scapula
Innervation: Dorsal scapular: nerve and C3-C4 spinal nerves
Main actions: elevates and downwardly rotates the scapula
