Muscles of Scapular Region Flashcards
Proximal—> distal attachments of the deltoid muscle
from clavicle, acromion & spine of the scapula TO the deltoid tuberosity of the humerus
Actions of the deltoid
(anterior) - flexion and medial rotation
(middle) - abduction of humerus
(posterior) - extension, lateral rotation, horizontal extension
What is horizontal extension?
Bring arms into 90 degree abducted position parallel to the ground.
bring arms forward so that palms become closer together (while maintaining arms parallel to the ground)–> horizontal flexion
bring arms back to the original position so that they are in line with the frontal plane–> horizontal extension
Innervation of the deltoid muscles
axillary nerve
C5-6 anterior, middle, and posterior portions
Proximal–> distal attachments of the supraspinatus
from the medial 2/3 of the supraspinous fossa–> superior facet of the greater tubercle of the humerus & the shoulder joint capsule
Actions of supraspinatus
initiates humeral abduction & laterally rotates humerus; stabilizes glenohumeral joint (reinforcement of the superior aspect of joint capsule)
Innervation of supraspinatus
suprascapular nerve
C4-6
Proximal—>distal attachments of infraspinatus
from the medial 2/3 of the infraspinous fossa —> the middle facet of the greater tubercle of the humerus & to shoulder joint capsule
Actions of the infraspinatus
lateral rotation of humerus; stabilization of glenohumeral joint
Innervation of infraspinatus
suprascapular nerve
C5-6
Proximal–>distal attachments of teres minor
from the upper 2/3 of the dorsal surface of the lateral border of the scapula –> the inferior facet of the greater tubercle of the humerus & to shoulder joint capsule
Actions of the teres minor
lateral rotation of humerus; stabilizes GH joint
Innervation of teres minor
axillary nerve
C5-6
Proximal–> distal attachments of subscapularis
from the subscapular fossa —> the lesser tubercle of the humerus
Actions of subscapularis
medial rotation of humerus; stabilizes GH joint
Innervation of subscapularis
upper & lower subscapular nerves
C5-6
Proximal–> distal attachments of teres major
from the dorsal surface of the inferior angle scapula & lower 1/3 of the lateral border of the scapula —-> medial lip of the intertubercular sulcus of the humerus
Actions of teres major
humeral adduction, medial rotation, & extension
Inn. of teres major
lower subscapular nerve C5-6
C5-6
spinal cord segments of deltoid muscle
C5-6 (anterior, middle, and posterior portions)
spinal cord segments of supraspinatus muscle
C4-6
spinal cord segments of infraspinatus
C5-6
spinal cord segments of teres minor
C5-6
spinal cord segments of subscapularis
C5-6
spinal cord segments of teres major
C5-6
What surrounds the axillary artery, vein and cords of the brachial plexus?
The axillary sheath
–> a piece of fascia
