MSK 1 - Shoulder and Scapula Flashcards
What does the shoulder girdle consist of?
scapula, clavicle and all muscles attached to these
Superficial muscles of posterior shoulder
- trapezius
- lattismus dorsi
Deep muscles of posterior shoulder
- levator scapulae
- rhomboid minor
- rhomboid major
Action and innervation of trapezius
- lifts arm above shoulder
- accessory nerve
Action and innervation of lattismus dorsi
- extends, adducts, medial rotation of arm
- thoracodorsal nerve
What innervates all of the deep muscles in the posterior shoulder?
dorsal nerve of the scapula
What do the rhomboid major and minor do?
retract scapula
Intrinsic muscles of the shoulder - action and innervation
- deltoid: abducts arm 15-90 - axillary nerve
- teres major: adducts shoulder - subscapular nerve
What does the axillary nerve supply in the shoulder?
- deltoid
- teres minor
Rotator cuff muscles
- subscapularis
- infraspinatus
- supraspinatus
- teres minor
Nerve supply of all but one of the rotator cuffs
SUBSCAPULAR NERVE
- teres minor: axillary nerve
Action of supraspinatus and infraspinatus
S: abduct arm 0-15
I: lateral rotation of arm
Which muscles laterally rotate the arm?
- infraspinatus
- teres minor
What does the subscapularis do?
medially rotates arm
Ball and socket joint of the shoulder allows what?
flexibility and RANGE OF MOVEMENT
Resting tone of posterior rotator cuff muscles allows..
head of humerus to be pulled into shoulder joint
What deepens the cavity of the shoulder?
glenoid labrum
What nerve can be damaged as a result of shoulder dislocation?
axillary nerve
- paralysis of deltoid
Humerus fracture will affect what nerve?
radial nerve - winds round spiral groove of humerus
