Scapular and Deltoid Regions ROTATOR CUFF Flashcards
Shoulder Region
where the upper limb attaches to the trunk
comprised of the:
clavicle, scapula, and proximal humerus
includes:
superficial back muscles that attach to and move the humerus
extrinsic and intrinsic muscles
superficial extrinsic Back and Shoulder
trapezius
latissimus dorsi
deltoid
Trapezius Origin
superior nuchal line
external occipital protuberance
ligamentum nuchae
C7-T12 spinous processes
Trapezius
Insertion
lateral 1/3 of clavicle
acromion
scapular spine
(origin for deltoid)
Trapezius
innervation
NOT INNERVATED BY the BRACHIAL PLEXUS
spinal portion of accessory nerve CN 11 (motor only)
ventral rami C3-C4 (sensory only)
Trapezius
Functions
upper fibers: elevate scapula
lower fibers: depress scapula
together: upwardly rotate scapula (with serratus)
middle: retract scapula
Latissimus Dorsi
origin
T7-T12 spinous processes
ribs 9-12
thoracolumbar fascia
iliac crest
Latissimus Dorsi
insertion
floor of inter tubercular groove of humerus
Latissiums Dorsi
innervation
Thoracodorsal nerve
ventral rami C6-C8
Latissiums Dorsi
Functions
medially rotates
extends
adducts humerus at the shoulder joint
fixed insert: raise body towards upper trunk as in hoisting the body
Deltoid
Origin
- lateral 1/3rd of clavicle
- acromion
- scapular spine
Deltoid
Inserts
convergent tendon into the deltoid tuberosity of humerus
Deltoid
innervation
axilary nerve C5-C6
Deltoid
Functions
Chief humeral ABductor (following initiation of abduction by the supraspinatus muscle; after about 15-20 deg flexion)
- Anterior: chief humeral flexor and medially rotates humerus
- Posterior: extends and laterally rotates humerus
- Middle: primary ABductor of humerus
Extrinsic Shoulder Muscles are:
Rhomboids
Levator Scapulae
Rhomboids Major
Origin
spions processes of T2-T5
Rhomboids Minor
Origin
spinous processes of C7-T1
Rhomboids Together Insertion
together along the medial border of the scapula from scapular spine to interior angle
Rhomboids
innervation
dorsal scapular nerve
C5
Rhomboids
functions
scapular retraction (squeeze shoulder blades together) downward rotation of the scapula
Levator Scapulae
Origin
posterior tubercules of transverse processes C1-C4
Levator Scapulae
Insert
superior angle and upper medial border of scapula
Levator Scapulae
innervation
ventral rami C3-C4
dorsal scapular nerve C5
Levator Scapulae
Functions
scapular elevation
downward rotation of scapula
Reverse actions:
fixed scapula: lateral flexion of cervical spine to ipsilateral contraction
billaterally assists is extension of the cervical spine
Intrinsic Shoulder Muscles:
originate off the scapula and insert on the humerus
SITS muscles: Rotator Cuff
Teres Major
Rotator Cuff Muscles
Supraspinatus
Infraspinatus
Teres Minor
Subscapularis
Supraspinatus
origin
supraspinous fossa of scapula
Supraspinatus
inserts
superior facet of greater tubercule of humerus
Supraspinatus
innervation
not sure yet
Supraspinatus
functions
initiates first 15-20 degrees of humeral ABduction
Infraspinatus
origin
infraspinous fossa of scapula
Infraspinatus
inserts
middle facet of greater tubercle of humerus
Infraspinatus
innervation
Suprascapular nerve
Infraspinatus
functions
external rotation of humerus
Teres Minor
Origin
teres minor fossa of scapula
Teres Minor
inserts
INNERvation
interior facets of greater tubercle of humerus
axillary nerve C5-C6
Teres Minor
functions
external rotation of humerus
Subscapularis
origin
Subscapular fossa of scapula
Subscapularis
inserts
lesser tubercle of humerus
Subscapularis
innervation
upper and lower subscapularis nerves
Subscapularis
functions
internal rotation of humerus
ADduction of the humerus
Teres Major
origin
posterior surface of interior angle of scapula
Teres Major
inserts
meidal lip or crest of inter tubercular groove of humerus
Teres Major
innervation
lower subscapular nerve
C5-C7
Teres Major
function
extension
ADductions
Medial rotation of humerus
humeral ADduction mechanics
large deltoid force plus
smaller supraspinous force equals
translation of the humeral head superiorly
prevention of humeral head from being driven to the coracoacromial arch and creating impingement
1.Subscap
2. infraspinatus
3. teres minor
exert downward translational force on humeral head
together maintain normal positioning for humeral head during ABduction and prevent impingement
Trapezius muscle is innervated by:
cranial nerve 11 (spinal portion of accessory nerve)
brachial motor to the muscle
Ventral rami C3-C4 convey sensory info from muscle to CNS
thoracodorsal nerve formed:
derives from:
innervates:
by ventral rami C6-C8
posterior cord of the brachial plexus
Latissimus Dorsi
Axillary nerve is:
C5-C6 terminal branch of the posterior cord of the brachial plexus runs posteriorly through axilla inferior to humeral head exits the quadrangular space
Axillary nerve supplies
teres minor first
then deltoid
Axillary terminates as:
cutaneous nerve
upper lateral brachial cutaneous nerve
supplies skin upper lateral arm
Suprascapular nerve
innervates:
C5-C6 supraspinatus first runs around scapular notch to infraspinatus runs posteriorly and inferior to the transverse scapular ligament
Suprascapular nerves orginiates and goes to:
upper superior trunk of brachial plexus
goes to transverse scapular ligament
Upper and Lower Subscapular nerves supply:
C5-C7
Subscapularis
Teres Major
derive from posterior cord of brachial plexus
blood to Trapezius
transverse cervical artery
branch of subclavian artery
blood to supraspinatus and infraspinatus
suprascapular artery over transverse ligament and suprascapular nerve goes under transverse ligament
(branch of subclavian artery)
Suprascapular artery travels:
with suprascapular nerve under the transverse scapular ligament to supply muslces:
supraspinatus and infraspinatus
posterior humeral circumflex artery
supplies and travels:
(branch of axillary artery)
supplies: teres minor & deltoid
travels: with axillary nerve to exit quadrangular space
Subscapular artery supplies:
(LARGEST branch of axillary artery)
latissimus dorsi
teres major
Collateral Circulation of dorsal scapular region:
see the next three cards
Supraspinous fossa supplied by:
suprascapular artery
Infraspinous fossa supplied by:
- dorsal scapular artery (transverse cervical)
- suprascapular artery
- circumflex scapular artery
Significance of Collateral Circulation of dorsal scapular region:
supraspinatus tendon frequently impinged in coracoacromial arch
tendons have poor blood supply
may be a factor affecting the capacity of muscle to repair following trauma or surgery
extrinsic muscles
originate somewhere else and insert in the area
intrinsic muscles
originate in the area and insert in the area
superior quadrangular space
teres minor
subscap
posterior quadrangular space
teres major
medial border of quadrangular space
long head of triceps
lateral border of quadrangular space
surgical neck of the humerus