Lecture 3: Upper Limb-Shoulder Girdle Flashcards
Acromion
process of scapula that joins to the clavicle
Glenoid Cavity
ball and socket of joint on scapula that connects scapula to humerus
coracoid process
medial to glenoid cavity of scapula
muscle and ligament atachment
Calvicle functions (3)
- attach the upper limb to the trunk as part of “shoulder girdle”
- protects the underlying neurovascular structures supplying the upper limb
- transmits force from the upper limb to the axial skeleton
Shoulder joint/glenohumoeral
humerous articulates with the glenoid fossa of the scalpula
represents the major articulation of the shoulder girdle
most mobile joint in human body
Acromioclavicular joint
involves the lateral end of the clavicle and the acromion of the scalpula
can be palpated during shoulder examination, 2-3 cm medially to the tip of the shoulder
no muscles act directly on the joint, but the joint allows for axial rotation and anteropsterior movements
Subaracromial Bursa
Location
function
L: Lies between deltoid muscle and joint capsule in the superiolateral aspect of the joint
superficial to supraspinatus tendon
function: reduces friction underneath deltoid muscle- allowing for increased range of motion
subscapular bursa
Location
function
Location: between supscapularis tendon and the scapula
function: reduces wear and tear on the tendon during movement at the shoulder joint
Bursitis
iflammation of bursa, can be a cause of shoulder pain
Glenohumeral ligament
location
function
L: made up of a superior, middle, and inferior ligament
responsible for connecting the glenoid fossa to the humerus
f: protect the shoulder and prevent it from dislocating-primary stabilizer
Deltoid
insertion
blood supply
innervation
actions
attached to the spine of the scapula and lateral third of the clavicle
Inserstion/apex: attached to lateral body of humerous on a point known at deltoid tuberosity
BS: receives blood from thoracoacromial branch of axillary artery
Innervation: axillary nerve
Actions:
- anterior fibers=flexion and medial rotation
- posterior=extension and lateral roation
- lateral fibers=major abductor of the arm
- ambulation=anterior of the deltoid works with pectoralis major when walking
Muscles of the soulder (12)
- deltoid
- pec major
- trapezius
- latissimus dorsi
- levator scapulae
- rhomboid major
- thomboid minor
- supraspinatus
- infraspinatus
- teres minor
- subscalpularis
- serattus anterior
- teres major
Scapula
triangular flat bone/”shoulder blade”
muscles that move the arm attach to fossa (depressions) in the scapula
-supraspinous fossa, infraspinous fossa
Calcivle overview
joins the sternum anteriorly and the scapula laterally to help support the shoulder
-most frequent broken bone due to FOOSH (fallen onto outstretched hand) or blows to the shoulder
Humerous
proximal region articulates with the glenoid fossa on scalpula, forming glenohumiral joint
distally-humerous joind with head of radius and trochlear notch of ulna
Dorsal muscles of Upper limb (4)
- Trapezius
- latissimus dorsi
- levator scapulae
- rhomboid major
Trapezius
location
insertion
movement
L: triangular muscle that covers posterior neck and extends across the posterior shoulder - most superficial
I: inserts on clavicle and scapula
M: enables raising of shoulders and pulling back of shoulders
-accessory nerve to shrug shoulders
can also extend head and move side to side
Latissumus dorsi
Location
Origin
Movement
L: wide muscle of lower back and lateral trunk
O: from vertebral spine in middle of lower back, covers inferior half of thoracic region forming posterior portion of axilla
M:extends arm, bringing it down
primer mover in arm adduction and medial rotation of upper limb
Rotator Cuff muscles (4)
- Supraspinatus
- Infraspinatus
- Teres Minor
- Subscalpularis
*SITS
Supraspinatus
function isolate
assists in abduction and external rotation of the shoulder
-Isolate: empty can
Infraspinatus
function isolate
assists in external rotation and abduction of the shoulder
Isolate: hold arm, flex at 90 degrees adducted, attempt to resist during external rotation
Teres Minor
assists in external rotation and abduction
-contributes up to 45% of external rotation, may compensate for tears of infraspinatus
Anterior fibers of deltoid
flexion and medial rotatio
posterior fibers of deltoid
extension and lateral rotation
lateral fibers of deltoid
major abductor of the arm
ambulation of deltoid
anterior head of deltoid works with pec. major when walking
Brachail plexus parts (5)
- roots- c5, c6, c7, c8, t1
- trunks- superior, middle, inferior
- divisions- anterior and posterios
- cords- lateral, posterial, medial
- branches
- musculocutaneous (c5, c6, c7)
- axillary (c5,c6)
- radial (c5,c6,c7,c8,t1)
- Median (c5, c6, c7, c8, t1)
- ulnar c7, c8, t1
**Read That Darn Cadaver Book
Roots of brachial plexus (5)
C5, C6, C7, C8, T1
Trunks of brahcial plexus (3)
superior, middle, inferior
Divisions of brachial plexus (2)
anterior and posterior
Cords of brachial plexus (3)
lateral, posterior, medial
Branches of brachial plexus (5)
- musculocutaneous (C5, C6, C7)
- axillary (C5, C6, C7, C8, t1)
- Radial (C5, C6, C7, C8, T1)
- median (C5, C6, C7, C8, T1)
- Ulnar (C7, C8, t1)
Axillary nerve
C5 and C6
innervates teres minor and deltoid muscles
Muscolocutaneous nerve
C5, C6, C7
innervates brachialis, biceps brachii, and coracobrachialis muscles
Median nerve
C6-c11
innervates most of the flexor muscles in the forearm, the thenar muscles, and the two lateral lumbricals associated with the index and middle fingers
Radial nerve
C5-T1
innervates triceps bracii and the muscles in the posterior compartment of the forearm, primarily extensors of the wrist and fingers
Ulnar nerve
C8 and T1
innervates the muscles of the hand (apart from the thenar muscles and the two lateral lumbricals) flexor carpi ulnaris and medial half of flexor digitorum profundus
Axillary Artery
lies deep to the pectoralis minor and is enclosed in the axillary sheath
Brachial artery
supplies the arm, branches to the right and left ulnar and radial and then digital arteries
lympatic drainage groups of axilla(5)
- pectoral (anterior)
- subscalpular (posterior)
- brachial/humeral (lateral)
- central
- apical
pectoral axillary lymph drainage group (anterior)
receives lymph primarily form the anterior thoractic wall, including most of the breast
supscapular/posterior axillary lymph drainage group
receive lymph from the posterior thoracic wall and scapular region
Brachial/humeral axillary lymph drainage
receive most of the lymph drained from the upper limb
central axillary lymph drainiage
they receive lymph via efferent vessles from the pectoral, subscapular, and humeral axillary lymph node groups
apical axillary lymph drainage
receive lymph from efferent vessles of the central axillarly lymph node groups
also received lymph from lymphatic vessles accompanying the caphalic vein
Venous drainage
palmar digital veins and palmar metacarpal veins deliver deoxygenated blood from the tissues of the fingers and palm to the superficial and deep palmar venous arches
then to the radial and ulnar veins, moving back up the arm before entering the brachial vein to the axillary vein to the subclavian vein before forming the brachiocephalic vein with blood returning from the head
or
Deoxygenated blood follows…
tissues of fingers -> palmar digital veins + palmar metacarpal veins -> sperficial + deep palmar venous arches -> radial + ulnar veins -> up arm -> brachial vein -> axillary vein -> subclavian vein -> brachiocephalic vein
median cubital vein
cephalic vein and basili vein meet in the middle with median cubital vein
Cavicle fracture
categorization risk presentation exams/imaging dx tx
C:categorized by location
- 69% middle
- 28% distal third
- 3% proximal third
R: FOOSH, fall or blow to should, traffic accidents, sports injury
P: pain that is well localized and exacerbated by movement of the arm
- may also report snapping or cracking sensation
- PE may reveal hematoma, bone angulaton (may see tinting of skin), point tenderness, crepitus (grating sound from bone-bone friction)
E/I: important to perform neurovascular and lung exam, looking for other injuries particularly high impact injury
Dx: singel AP xray
tx: pain control and reduction of motion until clinical union occurs
- sling or figure 8 to restrict shoulder motion to less than 30 degrees of abduction, forward flexion, or extension
- icing intermittently during the first 48 to 72 hours
- emergent if open reduction and fixation is needed
Dislocation of the shoulder joint
location description
cause
D: dislocations described by where the humeral head lies in relation to the glenoid fossa
- anterior 95%
- posterior 4% (usually from seizure or electrocution
- inferior 1%
C: anterior dislocation is usually causes by excessive extension and lateral rotation of the humerus.
-humeral head is forces anteriorly and inferiorly into the weakest part of the joint capsule. tearing of the joint capsule is associates with increased risk of future dislocations
- axillary nerve runs in close proximity to shoulder joint and around the surgical neck of the humerus so it can be damaged with dislocation or with attempted reduction
- injury to axillary nerve causes paralysis to deltoid and loss of sensation
Rotator cuff tear
Cause can be multifactoral
-degeneratoin, impingement and overload may all ctonribute
-most often begin as partial tears to the supraspinatus and overtime progress to full thickness to include infraspinatus, subscalpularis, and biceps tendon
RF: sports, occupations requiring overhead activity
CP: paint and weakness over the lateral deltoid and is exacerbated by overhread activites and at night
PE:painful arch test (abduction beyone 90 degrees), drop arm test (failure to smoothly control shoulder adduction, pain and weakness with external rotaion, empty can test
Dx: plain radiographs are usuallk normal MSK US, MRI
tx: depends on duration of symptoms, shoulder dominancem type of tear and patient characteristics
- tx typically surgical repoar and/or PT
Sapula
muscles that move the arm attach to the fossa in this bone
Hill-sach’s lesions
impaction fracture of posterolateral humoral head against anteroinferior glenoid can occur with shoulder joint dislocation
Bankart lesions
detachment of antero-inferior labrum with or without and avulsion fracture can occure following antrior shoulder joint dislocation
