Muscles Practical: Back, Shoulder

Trapezius

*

Latissimus Dorsi

origin: lumbodorsal fasica, spine of 6 thoracic vertebrae, lumbar vertebrae, iliac crest

insertion: teres major, interbubercular suclus of humerus

action: mover of arm extension and rotation

innveration: thoracodorsal nerve ( C6-8)

erector spinae group

serratus posterior inferior

teres major

*

supraspinatus
origin: supraspinous fossa of scapula

insertion: superior part of greater tubercle of humerus

action: initiates abduction of the arm

innervation: suprascapular nerve

*

Infraspinatus

origin: infraspinous fossa

insertion: greater tubercle posterior to the insertion of the supraspinatus

action: rotates arm laterally

innveration: suprascapular nerve

*

subscapularis

orgin: subscpular fossa

insertion: lesser tubercle

action: rotate arm medially

innervation: subscapular nerves (C5-7)

teres minor

*

Levator Scapulae

origin: transverse processes of C1-C4

Insertion: medial border of the scapula

Action: elevates and adducts scapula

innervation: cervical spinal nerves and dorsal scapular nerve (C3-C4)

rhomboid major

rhomboid minor