MS II Flashcards
anatomy of sternoclavicular jt classification mechanical/ functional resting position closed pack position capsular pattern
- anatomically complex (b/c disc)
- mechanically: bi-axial sadldle / functionally: ball and socket
resting position = arm at side
closed pack= abduction 90 degrees
capsular pattern= pain with extremes of motion
osteokinematics of SC joint (2)
- protraction/retraction = concave on convex
2. elevation/ depression = convex on concave
biomechanics of SC jt: ROM and axis
elevation/ depression
protraction/ retraction
rotation
elevation = 45-60 degrees
depression = 5 degrees
around sagittal axis (z)
protraction & retraction = 15 degrees
around vertical axis (y)
rotation = 30-50 degrees
around longitudinal axis of clavicle (x)
ligaments (3) and capsule of sternoclavicular jt
- capsule is reinforced by SCM fibers
3 ligaments:
- anterior/ posterior sternoclavicular ligament
- **costoclavicular ligament - anterior and posterior bands
- interclavicular ligament
directionality of sternoclavicular ligaments
directionality of costoclavicular ligaments (2)
sternoclavicular lig: a/p- both run inferior and oblique (very short)
costoclavicular lig:
anterior runs upward and laterally
posterior runs upwards and medially
these two criss-cross to increase stability
attachments of costoclavicular ligaments
upper surface of first rib and cartilage -> inferior surface of clavicle
anterior runs laterally, posterior runs medially
anatomy of acromioclavicular jt classification mechanical/ functional resting position closed pack position capsular pattern
classification: anatomically simple
mechanically = compound plane gliding joint/ functionally = ball and socket joint
resting position = arms at side
closed pack position = upward rotation of scap with arm at abduction
capsular pattern = pain with elevating arm or horizontal adduction, ltd full extension
ligaments of AC joint (3)
general purpose/ attachements
- acromioclavicular ligament** -covers superior part of joint * most likely to rupture
- coracoacromial ligament
- coracoclavicular ligament
a. trapezoid
b. conoid (triangular)
both attach to bottom of clavicle and serve to hold down clavicle
biomechanics of AC and ROM (3)
- saggital axis: ab/adduction = upward and downward rotation (of inferior angle of scapula)
ROM 20-30 degrees - vertical axis: winging - vertebral border pulling away from thorax during protraction/ retraction
ROM 30-50 degrees - long axis: tipping = sagittal plane, flexion/extension
ROM 30 degrees
scapulothoracic joint
ligaments (2)
not a true joint, just an articulation
ligaments:
- coraco-humeral
- superior transverse; converts scapular notch into foramen
articular surfaces of GH joint
head of humerus is covered with hyaline cartilage; faces
superior, medially, and posterior
glenoid faces superior, lateral and anterior and is smaller than head of humerus… this is why we have a labrum
glenoid is < 1/3 as wide of head of humerus
inferior capsule of GH joint
redundant fold that allows for movements. the head of humerus needs to drop inferior into capsule for any movement to occur.
adhesive capsulitis affects inferior capsule of GH joint
what arm position puts most stress on SITS?
IR and flexion or aBduction to 90 degrees
4 ligaments of GH joint
- capsule
- superior, middle, inferior lGH ligaments
- coracohumeral ligament
- transverse humeral ligament
capsule of GH joint
encompasses…
least supported…
5 tendons that reinforce capsule
encompasses long head of bicep and goest to mid shaft
weakest inferior
tendons that reinforce capsule:
anterior: subscap tendon
posterior: infraspinatus and teres minor
superior: supraspinatus
inferior: long head of tricep
GH ligament attachments
superior band
middle band
inferior band
blend with labrum; origin at medial margin of glenoid cavity =>
superior band: passes along medial edge of bicep tendon and attaches above lesser tubercle
middle band: lower part of lesser tubercle
lower band: lower part of anatomical neck
coracohumeral ligament attachments
lateral border of root of coracoid => greater tubercle , blends with supraspinatus tendon
transverse humeral ligament attachements/ purpose
canal for bicep tendon
ROM of GH joint
flexion/ abduction = 120
extension = 55
adduction = return to neutral
ER= 90 degrees IR = 60-70 degrees
2 spaces of upper limb girdle and muscles that create them
spaces are for nerves and vessels to pass thru
- triangular space - long head of tricep lateral, teres minor &, teres major
- quadrangular space- tricep (long and short heads) teres major & minor
GH joint
resting position
closed pack
capsular pattern of GH joint (3)
resting position = 55 degrees abduction, 30 degrees horizontal abduction
closed pack = max abduction & ER
capsular pattern: ER
aBduction
IR
8 bursae
- btwn subscap and joint capsule
- btwn infraspinatous & joint capsule
- summit of acromion
4 btwn coracoid and capsule - behind coracobrachialis
- btwn teres major & long head of tricep
- ant & post to lats
- subdeltiod (subacromial)
scapulothoracic group
aka
muscles (4)
movements
a.k.a. axioscapular
muscles: pec minor levator scapulae rhomboids serratus anterior
movements:
elevation/depression of scapula
upward/downward rotation
protraction/ retraction
scapulohumeral group
muscles (7)
movements
flexion/extension of humerus
ab/adduction of humerus
IR/ER
muscles: subscap teres major/ minor supraspinatus infraspinatus coracobrachialis deltoids
thoracohumeral group
a.k.a.
muscles (2) and each of their movements
a.k.a. axiohumeral
pec major: IR, flexion, horizontal adduction
lats: IR & extension of humerus
referred pain to the shoulder region from: (4)
- c-spine
- t-spine
- viscera
- myocardium
where is protraction/ retraction taking place?
occurs as SC joint and brings scap along, small amount of AC
where is aBduction taking place?
elevation of clavicle at SC joint, upward rotation at AC joint
movement occurring during flexion by degree (3)
- 1st 30 deg = GH joint
- 30- 120 deg = GH joint & ST
- 120-180 deg = ST
degrees of movement during aBduction (and what movement) ST jt AC jt SC jt GH jt
*pic on pg 59 of packet
ST jt upward rotation = 60 degrees AC jt upward rotation = 30 degrees SC jt elevation = 30 degrees and posterior rotation GH jt abduction = 120 degrees total = 180 degrees
**look at pg 59 of packet
biomechanics of ELEVATION at the SC jt
during elevation which direction is the clavicle rolling and sliding?
which ligaments are being shortened?
which ligaments are being lengthened?
p. 60 of packet
during elevation which direction is the clavicle rolling and sliding?
the clavicle rolls superomedial and slides inferior
*convex on concave so osteokinematics are opposite of arthrokinematics**
which ligaments are being shortened during elevation?
sternoclavicular and intraclavicular ligaments
which ligaments are being lengthened?
costoclavicular
biomechanics of DEPRESSION at the SC jt
during depression which direction is the clavicle rolling and sliding?
which ligaments are being shortened?
which ligaments are being lengthened?
p. 60 of packet
during depression which direction is the clavicle rolling and sliding?
clavicle rolls inferior/ medial and slides superior
* convex on concave so osteokinematics and opposite of arthrokinematics**
which ligaments are being shortened?
costoclavicular
which ligaments are being lengthened?
sternoclavicular and intraclaviular
biomechanics of retraction
during retraction which direction is the clavicle rolling and sliding?
which ligaments are being shortened?
which ligaments are being lengthened?
p. 60 of packet
during retraction which direction is the clavicle rolling and sliding?
clavicle is rolling and sliding posterior
*concave on convex so arthrokinematics = osteokinematics**
which ligaments are being shortened?
posterior sc ligament
which ligaments are being lengthened?
costoclavicular ligament & anterior sc ligament
synergistic muscle activity of arm elevation (abduction) at GH joint with delts and RC
3 things that occur during arm elevation and the muscles that do it
rotator cuff + deltioids
- compression of humeral head
supraspinatus - depression (/inferior glide) of humeral head
subscap, inraspinatus, teres minor - centering of humeral head
all rotator cuff muscles
during IR and ER of the humerus, what directions is it rolling and sliding?
what muscles are working/ being stretched?
IR: rolls anterior and slides posterior
teres major is contracting?
ER: rolls posterior and slides anterior
infraspinatus contracts while subscap is being stretched and preventing excessive ant glide
what muscles work in synergy for arm elevation besides RC + delts?
upper and lower traps + serratus anterior
3 grades of AC separation
severity and ligaments affected
grade 1*: minor separation of AC joint w/ either stretch or tear of AC lig
grade 2*: AC joint more separated, AC lig completely torn
grade 3: AC joint completely separated, AC & coracoclavicular lig torn
** grade 1 & 2 may not be visible on x-ray and may be lax on joint play assesment
GH painful arcs (by degree) (2) for diagnostic purposes
GH painful arc = 45 (-60)- 120 degrees
AC painful arc = 170-80
sensitivity vs. specifity
sensitivity => true positive (false negative)
% of positives which are correctly identified
specificity => true negative (false positive)
% of negatives which are correctly identified
positive predictive value
negative predictive value
positive predictive value = proportion of people who truly have the condition relative to all pts who test (+)
negative predictive value= proportion of people who truly do not have the condition relative to all pts who test (-)
anterior instability tests (3)
- anterior apprehension
- anterior drawer
- jobe relocation test
posterior instability tests (3)
- posterior apprehension
- posterior drawer
- rockwood test
inferior instability special tests (2)
- sulcus sign (2 variations)
2. faegin test
multidirectional instability special test
- rowe test
anterior, inferior (stand behind pt); posterior (stand in front of pt)
bicipital tendon tests (3)
- yergason test
2. speed’s tests (2) - isometric
RC tears special tests (2)
- drop arm test (eccentric)
2. empty/ full can test (isometric)
supraspinatus special tests
1 test, pt in scaption/abduction ~80 + IR => isometric resistance to downward pressure
impingement tests (3) and what a positive sign is
- hawkins kennedy test
- yocum test
- neer (to ear) test
(+) on all 3 = pain secondary to compression under coracoacromion lig & acromion
labral tear specific tests (and specifics of what part of labrum) (4)
- cranks test - labral pathology
- o’briens test - superior labrum vs. AC jt
- Mimori new pain provocation- superior labrum
- bicep load test
During PROTRACTION
What direction is the clavicle rolling and sliding?
what ligaments are being lengthened?
What ligaments are being shortened?
During PROTRACTION
the clavicle is rolling and sliding anterior
*concsve on convex so osteokinematics = arthrokinematics**
what ligaments are being lengthened?
posterior sternoclavicular
what ligaments are being shortened?
anterior clavicular
