muscles of the posterior axioappendicular shoulder

Question 1

Latissimus Dorsi O/INS/A/INN

Answer 1

Latissimus dorsi is a superficial posterior axioappendicular muscle
Origin - Spinous processes of T7-T12, thoracolumbar fascia, inferior 3-4 ribs and iliac crest
Insertion - Floor of bicipital groove of humerus
Action - Extension, adduction, internal rotation of humerus
Nerve supply - thoracodorsal nerve

Question 2

Trapezius O/INS/A/INN

Answer 2

Trapezius is a posterior axioappendicular muscle. It has 3 parts superior, middle and inferior
Origin - Medial 1/3 of the superior nuchal line, external occipital protuberance, nuchal ligament, spinous processes of C7-12
Insertion - Lateral 1/3 of the clavicle, acromion, spine of the scapula
Action - Superior aspect: elevates scapula
Middle aspect: Retracts scapula
Inferior aspect: depresses scapula
Nerve supply - Accessory nerve

Question 3

Rhomboid major and minor O/INS/A/INN

Answer 3

Rhomboids are a posterior axioappendicular muscle deep to trapezius. It has 2 parts rhomboid major and minor
Origin - minor: spinous processes of C7 & T1
major: spinous processes of T2-5
Insertion - minor: medial border of scapula above the spine of the scapula
major: medial border of scapula below the spine of the scapula
Action - Retraction and medial (downward) rotation of scapula
Nerve supply - dorsal scapular

Question 4

Levator scapulae O/INS/A/INN

Answer 4

Levator scapula is a posterior axioappendicular muscle deep to the trapezius.
Origin - Medial border of scapula, superior to the spine of the scapula
Insertion - transverse processes of C1-4
Action - Elevates and downwardly (medially) rotates scapula, extension and lateral flexion of cervical spine
Nerve supply - dorsal scapular nerve