lecture 6: the shoulder complex Flashcards
what is the shoulder complex made up of
clavicle , scap , humerus
what are the 4 joints that make up the shoulder complex
GH joint
SC joint
AC joint
ST joint
how much motion of the shoulder complex is at the GH joint and ST joint
2/3 at GH
1/3 at ST
what is the normal ROM of the shoulder
180°
_____ stabilization is an active force that provides greater control than passive
dynamic
what occurs ipsilaterally with shoulder elevation
upper thoracic rotation
what is the only structural attachement between axial skeleton and the shoulder
sternoclavicular joint
what are the 3 degrees of freedom at the SC joint
elevation/depressoin
protraction /retraction
anterior/ posterior rotation
elevation/ depression (of the SC) happen between the ___ and ___
disc and clavicle
protraction/ retraction(of the SC) happen between the ___ and ___
disc and manubrium
anterior/posterior rotation (of the SC) happen between the ___ and ___
clavicle and 1st rub costocartilage
the articulation of the SC joint is what
2 plane synovial joint
the disc of the SC joint increases ___ and absorbs ___
congruence
forces
The SC joint creates 2 seperate cavities and acts as a ___ point during motion
pivot
during elevation / depression (at the SC joint) the clavicle ___ and ___ on the disc
rolls and glides
during protraction/retraction (of the SC joint) the sc ___ and ___ roll and slide on the ___
disc and clavicle
manubrium
which ligaments of the SC ligaments both limit A/P translation : posterior is primary
anterior and posterior SC ligament
the costoclavicular ligament limit ___ of the ___ clavicle
elevation
lateral
the anterior costoclavicular lig fibers run ___ and the posterior fibers run ____
laterally
medially
which ligament of the SC ligaments resist excessive depression of clavicle : and superior gliding of the clavicle on manubrium
interclavicular ligament
during elevation of the SC joint the ___ end of the clavicle moves upward
lateral
upward
during SC elevation the medial end rolls ___ and slides ____ on the sternun
medial
superiorly
inferiorly
during SC protraction the lateral clavicle moves ___ in the ___ plane
lateral
anteriorly
transverse
during protraction of the SC joint the medial clavicel does what on the sternum
rolls and slides anteriorly
during depression of the SC joint the lateral end of the clavicle moves___
downwards
during depression of the SC joint the medial end of the clavicle does what
rolls inferiorly and slides superiorly
during retraction of the SC joint the lateral clavicle moves ___
posteriorly
during retraction of the SC joint the medial clavicle does what
rolls and slides posteriorly
what joint structure attaches the scapula to lateral clavicle
acromioclavicular joint
the AC joint is a ____ synovial joint with ___- DOF
plane
3
the AC joint allows the scapula to rotate during arm movement which ___ UE motion
increases
is the AC capsule strong or weak
weak
is the superior or inferior AC ligament stronger
superior
which ligament of the AC joint firmly unites clavicle and scapula
coracoclavicular lig
what 2 other ligaments make up the coracoclavicular lig of the AC joint
conoid and trapezoid lig
what does the conoid lig resist
inferior forces
what does the trapezoid lig resist
posterior translation
there is a coupled ____ clavicle rotation and scapula ____ rotation during arm elevation
posterior
upward
internal and external rotation(20-35°) of the AC joint occurs around the ___ axis
vertical
anterior and posterior tilting (20-40°) of the AC joint occurs around the ___ axis
oblique coronal
upward (30°) and downward (17°) rotation of the AC joint occurs around the ___ axis
oblique AP
is the AC joint stable ?
not rea;;t
is the AC joint susceptible to trauma and degenerative changes
yes
what is the most common trauma for the AC joint
contact sport or falls on shoulder with arm adducted
what joint is formed by anterior surface of scapula with throax
scapulothoracic joint
T/F: the ST joint is a true joint
false
the scapula rest from midline between ribs ___-___
2-7
what is the resting position of the scapula
internally rotated
tilted anteriorly
upwardly rotated
how many degrees of ST joint is required to upwardly rotate during arm elevation
60
if you have excessive internal rotation of the ST joint what is that called
scapular winging
what happens at the scapula during shoulder flexion/abduction
protraction
elevation
upward rotation