Shoulder Flashcards
SHOULDER: SCJ
connects (2), capsular (2), nerve (2), type, med vs. lat
space - shape, open where
clavicle - cave/vex (2G), congruency, degeneration, thicker ant/pos
rotational - seen where, axis + runs, agonist (2)
translation - small/big, horizontal ABD vs. ADD (trans + congruency)
- connects upper limb to axial skeleton, shoulder to thorax
- capsular: horizontal ADD & ELEV
- nerve: suprascapular & subclavius
- saddle joint
- medial: disc & manubrium, for PRO/RET
- lateral: disc & clavicle, for ELEV/DEP
- SCJ space: wedge, open superiorly
- clavicle: concave during PRO/RET, convex during ELEV/DEP, incongruent, no degeneration d/t disc, thicker anteriorly
- agonist: biceps & deltoids, coracobrachialis
ROTATIONAL
- ELEV/DEP (Z): seen in lateral clavicle
- PRO/RET (Y): seen in lateral clavicle
- UP/POS & DOWN/ANT ROT (X): seen in whole clavicle
- axis runs longitudinal through clavicle
TRANSLATION
- small magnitude
- ant/pos, sup/inf, lat/med
- horizontal ABD: lat trans = separate joint spaces
- horizontal ADD: med trans = congruent
SHOULDER: SCJ - Ligaments
interclavicular - where, against, protect (1)
costoclavicular - where, ant/pos lamina fibers, against
sternoclavicular - with, ant/pos (against)
which main, strongest
disc - divide what, sup vs. inf attachments (where + with + action), function (3)
interclavicular
- between left & right, against depression
- protect brachial plexus
costoclavicular
- between clavicle & 1st rib, against ELEV
- strongest, main
- ant lamina: fibers directed laterally
sternoclavicular
- with SCJ capsule
- anterior: prevent backward
DISC
- divides joint diagonally into 2 cavities
- superior attachment: clavicle, one unit with manubrium, pivot for ELEV/DEP
- inferior attachment: part of clavicle, pivot for PRO/RET
- function: inc joint congruency, dec friction, dissipate medially directed forces (since diagonal), absorb force
SHOULDER: ACJ - Ligaments
acromioclavicular - strength, against, sup vs. inf strength + cont with
coracoclavicular - trapezoid vs. conoid (med/lat + shape + vertical/horizontal + against)
which main
acromioclavicular
- first injured
- against DEP
- superior: supported by traps & deltoid so stronger, continuous with ACJ capsule
coracoclavicular
- main
- lateral trapezoid: quadrilateral, horizontal, against superior & posterior forces
- medial conoid: triangular, vertical, against superior forces
SHOULDER: ACJ
type, nerve (2), capsular, congruency, degeneration, clavicle & acromion flat vs. hooked
site of, allows
disc - orientation, made of, movement of UE leaves what
capsule- supported by (2), presence, strength
- plane, incongruent = degenerative
- capsular: horizontal ADD, ELEV
- nerve: suprascapular, lat. pectoral
- clavicle: flat (less movement), curved (yay)
- acromion: flat (more space), hooked (impinge)
- site of force transmission from UE to clavicle, allows scapular ROT
disc
- not oblique, made of fibrocartilage
- UE movement = meniscoid fibrocartilage within joint
capsule
- supported by GHL, CCL
- can be absent, weaker than SCJ’s
SHOULDER: ACJ - Arch
name (3), normal, formed by, against, component of, formed by (4)
if narrowed (=2 muscles), painful arc + why, injury (5)
space - where, tendon (2), ligament
coracoacromial/suprahumeral arch/supraspinatus outlet
- formed by head of humerus below arch, component of GHJ; coracoid process, acromion, inf ACJ, coracoacromial lig
- normal: 10mm
- against superiorly directed forces to humerus
- if narrowed = biceps & supraspinatus impinged
- painful arc: 60-120 since after 120 = clavicle ELEV & scapula UP ROT so more space again
- injury: type I (ACL), type II (ACL rupture + CCL), type III (both rupture), type IV (pos displaced clavicle), type V (inf displaced acromion)
subacromial space
- between humeral head & arch
- has rotator cuff & biceps tendon
- made by coracoacromial ligament
SHOULDER: ACJ
translation - small/big
rotary
- oriented to
- IR/ER: what moves, purpose
- ant/pos tilt: what moves, scapula x thorax in flex/abd
translation
- small magnitude
- ant/pos, sup/inf, lat/med
rotary
- oriented to plane of scapula
- IR/ER: bring glenoid fossa antmed/poslat; to keep humerus x glenoid
- ant/pos tilt: scapula moves; to maintain scapulothoracic congruency
- in FLEX/ABD: scapula moves POS/UP ROT on thorax
SHOULDER: STJ
type, % in elevation, static vs. dynamic, from to
length-tension how, force + otherwise
- false
- 1/3 in elevation
- static only so dynamic stab depends on ACJ
- from 2nd-5th ribs
- length-tension: deltoid will shorten at GHJ at some point but STJ allows lengthening at scapula & clavicle to allow further ROM
- allows FOOSH travel to scapula otherwise clavicular fx
SHOULDER: STJ
translation - (2G)
rotary
- up/down: SCJ (2) ACJ (1)
- IR/ER: accompany, medical
- ant/pos tilt: purpose
- which observable, primary
translation
- PRO/RET, ELEV/DEP
rotary
- up/down ROT: SCJ moves ant/pos ROT & ELEV/DEP, ACJ moves up/down ROT
- IR/ER: accompanies PRO/RET, winging
- ant/pos TILT: to keep scapula at rib cage
- primary & observable 1st
SHOULDER: GHJ
type
scapula - resting + normal (2), fossa faces, humeral head faces, fossa tilt, degeneration
inclination - where, normal, plane, inc/dec
torsion - where, normal, plane, inc/dec
- ball & socket
anatomical shit
- scapula in resting: anteverted, (N=10 ant 6-7 retro)
- glenoid fossa: faces slightly anterior, tilt up or down
- humeral head: faces supmedpos (opposite of fossa)
- easy degeneration
angle of inclination
- humeral head & neck x shaft, coronal plane
- normal: 130-150 (120)
- if inc = humeral head x glenoid fossa unstable
- if dec = humeral neck fx
angle of torsion
- humeral head & neck x condyles, transverse plane
- normal: 30 pos
- if inc = some instability
- if dec = humeral head x fossa unstable
SHOULDER: GHJ
labrum - thick where, made of + cover, function (1=1)
capsule - taut/slack + why, capsular vs. bony
bursa - separates (2), otherwise
RIC - (3) + (2), static/dynamic stab, purpose
labrum
- thicker in periphery, made of fibrous, covered in cartilage
- deepends fossa to dec translatory forces
capsule
- taut superiorly slack anterior & inferiorly = prevents humerus from sliding downward
- capsular: ABD ER
bursa
- separates supraspinatus & humeral head
- lead to muscle tear
rotator interval capsule
- sup GHL, sup GHJ capsule, CHL
- bridges suprapinatus & subscapularis tendons
- static only; dynamic stabilization in muscles
- prevents humerus from sliding down
SHOULDER: GHJ - Ligaments
GHL
- (2) foramen: where weak/dislocation
- which major + against + where
CHL - against, tunnel for (1)
glenohumeral ligament
- foramen of weitbrecht: between sup & middle; prone to ant dislocation
foramen of rouvier: between middle & inf
- superior: against ANT INF forces; at humeral neck
-middle: against ANT
- inferior: against ANT POS forces; at axillary pouch
SHOULDER: GHJ
rotary - flex/ext (ROM), ABD/ADD (greater tubercle does what)
rhythm - ratio, initial (ROM + what moves), ST axis shift, SCJ, ACJ (2), scapula, humerus (+ head at 60)
rotary
- FLEX/EXT: max 120 flex if only at GHJ
- ABD/ADD: greater tubercle moves under arch to continue ABD
rhythm
- 2:1 (GHJ:STJ)
- intial: 60 FLEX 30 ABD, scapula does not move yet
- ST axis shifts laterally from SCJ to ACJ during elevation
- SCJ: retraction
- ACJ: upward ROT, IR
- scapula: protraction
- humerus: ELEV, ER; humeral head moves sup til 60 then just stay
SHOULDER: Muscles
lat dorsi - primary/secondary, if WB how function, GHJ stability how + purpose
pecs major - primary/secondary, where, inc
teres major - primary/secondary + why, depend on, if not stabilized
rhomboids - synergist/offset what
pecs minor - primary/secondary, purpose, scapula (3)
latissimus dorsi
- primary
- if WB = pull pelvis upward to scapula & humerus
- GHJ stability: compresses joint during ABD for stability = otherwise humeral head will leave fossa while other muscles ELEV
pecs major
- secondary, ant to GHJ, inc ant humeral head trans
teres major
- secondary since only active when resisted
- depend on rhomboids; otherwise willl move scapula instead of humerus
rhomboids
- synergist with lat dorsi, offsets SA
pecs minor
- secondary, help lat dorsi & pecs major by depressing scapula at coracoid process
- scapula = IR, down ROT, ant TILT
SHOULDER: Muscles
muscles for upward rotation (2)
muscle for ST stabilization (1)
static stab - pressure + effect + by
dynamic stab
- force, (7), if disrupted
- deltoids: force, prime for + needs (2) d/t
- biceps: where, against, position
- supraspinatus: gravity as
- rotator cuff: against, which strongest, line of force + therefore
- muscles for UP ROT: traps, SA
- muscles for ST stabilization: SA
static stabilization
- negative pressure/suction effect by capsule
dynamic stabilization
- muscles have upward force against gravity
- friction, surface geometry, joint reaction force, gravity, prime mover, muscle stabilizer, capsule
- if disrupted = rely on static
- deltoid: upward force, prime for ABD & FLEX but needs rotator cuff to offset it
- biceps: above joint, against SUP INF ANT forces, regardless of position
- supraspinatus: gravity as synergist
rotator cuff
- teres minor & infraspinatus: against SUP POS
- subscapularis: against SUP ANT; strongest
- line of force in dependent arm position is inward = keep humerus in glenoid fossa
