L33 Shoulder Flashcards
What are the anatomical regions of the upper extremeties?
Shoulder (pectoral, scapular, deltoid regions)
Arm (brachium)
Forearm (antebrachium)
Hand (palmar/dorsal)
What are the bones of the shoulder (pectoral girdle)?
What bone makes up the arm?
Forearm?
Hand?
Clavicle and scapula
Humerus
- ulna (medial)
- radius (lateral)
- carpals (in wrist)
- metacarpals (in palm)
- phalanges (in digits)
How is UE Deep Fascia named?
Based on region (e.g. Deltoid fascia)
Deep fascia is continuous with
intramuscular septa that form
fascial compartments
intramuscular septa connects to bone
What are the dermatomes of the UE
C5-T1
What is the UE cutaneous innervation?
What nodes make up the superficial lymphatics?
Cubital Nodes: drain to humeral nodes
Deltopectoral nodes: drain to apical axillary nodes
These are superficial to deep fascia and follow superficial veins
What nodes make up the deep llymphatics?
What is the flow pattern of lymph?
Pectoral, Subscapular, Humeral, (central axillary and apical axillary?)
Located deep to deep fascia, follows deep veins
What are the bony features of the Scapula?
Scapular Spine: posterior superior ridge
Infraspinous fossa: Posterior body of scapula, inferior to spine
Supraspinous fossa: superior body of scapula
Subscapular fossa: anterior body of scapula
Coracoid process: “hook” projection on lateral edge of superior anterior scapula, helps stabilize stabilize should joint along w/ acromion
Acromion process: lateral end of spine, joins to clavicle, stabilizes shoulder joint
Glenoid cavity: site of articulation w/ head of humerus
Suprascapular notch: On superior anterior edge of scapula, medial coracoid process
What is the AC joint?
Acromioclavicular joint: connects clavicle to acromion. -synovial plane joint (rotation)
-partial articular disc process.
Stabilized by:
coracoacromial lig.,
acromioclavicular lig.,
coracoclavicular ligaments: trapezoid (lateral) and conoid (medial)
What is the SC joint?
- *Sternoclavicular (SC) joint**: connects clavicle to sternum
- synovial ball & socket
- articular disc
- strong
Stabilized by:
- *Interclavicular lig** (over jugular notch)
- *Ant/Post sternoclavicular** ligs
- *Costoclavicular** lig
Only joint between UE and body
How is the humerus joined to the scapula?
What are the joint’s components?
- *Glenohumeral (shoulder) joint**: head of humerus to glenoid cavity
- synovial ball in socket
- most freedom of any joint
Components (from exterior to interior):
Rotator Cuff tendons, Coracohumeral lig.
Glenohumeral ligs.
Glenoid Labrum: fibrocartilage
-extends socket
Shoulder joint summary of movements
SC
AC
Glenohumeral
Sternoclavicular (SC) joint
-circumduction
Acromioclavicular (AC) joint
-rotation
Glenohumeral (shoulder) joint
-flexion/extension, abduction/adduction,
medial/lateral rotation, circumduction
Extrinsic shoulder muscles: attachments
outside the UE, but act on UE; “axioappendicular”
trapezius: elevate, depress, retract
scapula
latissimus dorsi: extend, adduct, medially
rotate humerus
levator scapulae: elevate scapula, inferiorly
rotate glenoid cavity
rhomboids: retract scapula, inferiorly
rotate glenoid cavity
Pectoralis major: adduct, medially rotate humerus
Pectoralis minor: stabilize scapula
Serratus anterior: protract scapula
trapezius
PA: sup. nuchal line, EOP,
nuchal lig. Sp C7-T12
DA: clavicle, acromion process,
scapular spine
Act: elevate, depress, retract
scapula
Inn: spinal accessory n (CN XI)
latissimus dorsi
PA: sp T7-T12,
thoracolumbar fascia,
iliac crest
DA: intertubercular sulcus
Act: extend, adduct, medially
rotate humerus
Inn: thoracodorsal n
levator scapulae
PA: tp C1-C4
DA: medial border of scapula
Act: elevate scapula, inferiorly
rotate glenoid cavity
Inn: dorsal scapular n
rhomboid major & minor
PA: sp T2-T5, nuchal lig. (maj)
sp C7 & T1 (min)
DA: medial border of scapula
Act: retract scapula, inferiorly
rotate glenoid cavity
Inn: dorsal scapular n
pectoralis major
PA: clavicle, sternum, costal cartilage 1-6
DA: intertubercular sulcus
Act: adduct, medially rotate humerus
Inn: medial & lateral pectoral nn
pectoralis minor
PA: ribs 3-5
DA: coracoid process
Act: stabilize scapula
Inn: medial pectoral n
serratus anterior
PA: ribs 1-8
DA: medial border of scapula
Act: protract scapula
Inn: long thoracic n
Intrinsic shoulder muscles:
all attachments are within the
UE, “scapulohumeral”
Deltoid: abduct, medially rotate humerus
Supraspinatus: initiates abduction of humerus
Infraspinatus: laterally rotates humerus
Teres minor: adducts and laterally rotates humerus
Teres major: adducts and medially rotates humerus
Subscapularis: medially rotates & adducts humerus
Deltoid
What muscle aids deltoid action?
What is the deltoid a common site for?
PA: clavicle, acromion, scapular spine
DA: deltoid tuberosity
Act: abduct, medially rotate humerus
Inn: axillary n
Deltoid is aided by supraspinatus for first 15°
of abduction, remainder is primarily deltoid
and upward rotation of the scapula
Intramuscular injections, 2-3 finger breadths below
acromion process
supraspinatus
PA: supraspinous fossa
DA: greater tubercle of humerus (superior facet)
Act: initiates abduction of humerus
Inn: suprascapular n
infraspinatus
PA: infraspinous fossa
DA: greater tubercle (inferior facet)
Act: laterally rotates humerus
Inn: suprascapular n
teres minor
PA: lateral border of scapula
DA: greater tubercle (inferior facet)
Act: adducts and laterally rotates humerus
Inn: lower subscapular n
teres major
PA: inferior angle of scapula
DA: intertubercular sulcus
Act: adducts and medially rotates humerus
Inn: long thoracic n
subscapularis
PA: subscapular fossa
DA: lesser tubercle
Act: medially rotates & adducts humerus
Inn: upper & lower subscapular nn
Rotator Cuff: function and components
Increases stability of the shoulder (glenohumeral) joint
Rotator cuff muscles (SITS):
supraspinatus
infraspinatus
teres minor
subscapularis
Degenerative tendonitis of the rotator cuff:
What might lead to a tear?
Where is injury most common?
How is this injury tested?
Repetitive use → inflammation → impingement on coraco-acromial arch
Sudden strain on degenerating cuff
may lead to rotator cuff tearing
Injury to supraspinatus most common
Test: cannot initiate abduction; if fully
abducted, arm falls in an uncontrolled
manner during slow adduction
What are the major arteries of the shoulder (not including axiallary branches)?
Subclavian a. gives rise to:
Thyrocervical trunk which gives rise to:
-inferior thyroid a.
-transverse cervical a.
(w/ spinal access. n.)
-suprascapular a.
(w/ suprascapular n.)
Dorsal scapular a.
(w/ dorsal scapular n.)
Axillary a.
“Army over Navy”
What artery, nerve, and ligament is involved and how are they oriented?
- *Suprascapular a. courses superior** to the superior transverse scapular ligament
- *Suprascapular n. courses inferior** to the superior transverse scapular ligament
superior transverse scapular ligament covers suprascapular notch
Axillary a.
What are it’s boundaries and branches?
- *First part**: boundary = 1st rib to (pec minor?)
- *single branch: superior thoracic a**
- *Second part:** (beneath pectoralis minor?)
- *Two branches:**
- thoracoacromial a.:
- pectoral branch
- clavicular branch
- acromial branch
- deltoid branch
- lateral thoracic a.
- *Third Part:** Superior boundary = teres minor, inferior = teres major, medial = long head of tricep m, lateral = surgical head of humerus
- *Three Branches:**
- subscapular a.
- anterior humeral circumflex a.
- posterior humeral circumflex a.
Quadrangular (quadrilateral) space
Contains?
Boundaries?
Trauma or compression?
Contains:
Axillary n.
Posterior humeral circumflex artery
Formed by:
Teres minor
Long head of triceps brachii
Teres major
Surgical neck of humerus
- *Trauma or compression:**
- quadrangular space syndrome
- shoulder pain & parasthesia
Shoulder Veins
Transverse cervical &
Suprascapular veins →
External jugular v. →
Subclavian v.
