shoulder complex Flashcards
what are the trapezoid attachments
coracoid process to trapezoid line of clavicle
what are the conoid attachments
coracoid process to conoid tubercule of clavicle
what is the function of the coracoclavicular ligament
stabilizes AC joint
-limits medial displacement, protraction, elevation
what is the function of the acromioclavicular ligament
stabilizes AC joint
-limits superior migration of clavicle
what are the attachments of the acromioclavicular ligament
superior aspect acromial end of clavicle to adjacent acromion
what are the attachments of the coracoacrominal lig
lateral border coracoid process
acromion adjacent to clavicular articulation
what is the function of the coracoacrominal lig
prevents superior displacement of humeral head by forming the coracoacromial arch
what is the function of the coracohumeral lig
reinforces superoanterior aspects of joint capsule
what are the attachments of the coracohumeral lig
base of coracoid process
anterior aspect greater tubercule
what are the attachments of the costoclavicular lig
superior aspect of cartilage of first rib
undersurface of clavicle
what is the function of the costclav ligament
stabilizes SC joint
limits elevation of clavicle
what is the function of the superior transverse scapular lig
closes off suprascapular notch
what are the attachments of the superior transverse scapular lig
base of coracoid process
medial edge scap notch
what are the attachments of the glenoid capsule
circumference glenoid cavity to anatomical neck of humerus
what is the function of the superior GH lig
stabilizes against inferior translation of humerus on the glenoid with humerus at 0 degrees abduction
what is the function of the middle GH lig
stabilizies against anterior translation of humerus on glenoid
what is the function of the inferior GH lig
stabilizes against inferior translation of humerus on glenoic with humerus at 90 degrees abduction
what are the attachments of the GH ligaments
upper part medial margin of glenoid cavity
lesster tubercule
anatomical neck
which joints are synovial
all EXCEPT scapulothoracic
describe the joint surfaces at the SC joint
- clavicle is convex superior inferior
- manubrium concave superior inferior
- clavicle concave ant-pot
- manubrium convex ant-post
what are the ligaments of the SC joint
SC lig: ant and post
costcoclav lig
interclavicular lig
when is the costcoclav lig taught
with elevation and retraction
what kind of joint is the SC joint
saddle
what happens with protraction at the SC joint
anterior roll and glide of concave clavicle
what happens with retraction at the SC joint
posterior roll and glide
what happens with elevation at the SC joint
superior roll and inferior glide of convex clavicle
what happens with depression at the SC joint
inferior roll and superior glide
Discuss SC joint dislocation
- very rare
- direct trauma or blow to clavicle or FOOSH
- MUCH more common to break clavicle
- posterior type holds higher risk of injury to other structures
- post=surgery
what kind of joint is the AC joint
plane (gliding)
which ligaments are in the AC joint
- acromioclavicular
- coracoclav: trapezoid and conoid
describe movements at the AC joint with shoudler girdle motion
- protraction-retraction of scap= AP glide
2. adbuction-adduction of scap= rotation of acromion on clavicle
what is a separated shoulder
AC joint sprain
- fall on acromion
- progressive disruption of ligaments: AC joint, trapezoid, conoid
- then graded by displacement
- grades 1-3 can be managed nonsurgically
- grades 4-6 surgery
what kind of joint is the scapulothoracic joint
pseudo
talk about the scapulothoracic joitn
- muscular joint betwen scapula and trunk
- required for full ROM at GH joint
- no direct ligament attachment
what are the 3 rotations at the scapulothoracic joint
- upward/downward
- IR/ER
- ant/post tilt
what are the 3 purposes of scapulohumeral rhythm
- allows for greater shoulder ROM
- maintains optimal contact between humeral head and glenoid fossa
- assists with maintaing an optimal length-tension relationship of GH muscles
Describe the role of the T spine with bilateral shoulder motion
10-30 degrees thoracic extension with full shoulder elevation
Describe the role of the T spine with unilateral shoulder motion
10-30 degrees thoracic rot/sidebend
what kind of joint is the GH
ball and socket
largets ROM and movement in body
why is the GH the largets ROm and movement
- shallow joint
- extensive joint capsule
- limited ligamentous support
talk about the labrum
- static stabilizer
- glenoid fossa 1/4 size humeral head
- glenoid fossa without cartilage is more flat than concave
- concavity arises primarily due to labrum and to a less er extent from catilage
- glenoid shallow socket faces lateral, anterior and superior
- angle of inclination changes with position of scap
- labrum deepens socket 50-75%
talk about the joint capsule
- static stabilizer
- anterior and inferior thicker
what are the anterior GH ligaments and inferior pliable redundent ligamentous complex
static stabilizers
what does the superior glenohumeral lig resist
inferior translation in adducted position
what does the middle glenohumeral lig resist
ER at 45 degrees abduction/scaption
-courses along anterior joint from glenoid to humerus in superior inferior direction
talk about the inferior glenohumeral ligament
main static stabilizer of the GH joint with arm at 90 degrees abducrtion
what does hte anterior band inferior GH ligament resist
ER at 90 degrees abduction/scaption
what resists ER at 0 degrees abduction
- subscapularis 1st
- SGHL
what resists ER at 45 degrees abduction
- SGHL
- MGHL
what resists ER at 90 degrees abduction
anterior band IGHLC
what resists IR at 0 degrees abduction
posterior band IGHLC
what resists IR at 45 degrees abduction
anterior and posterior IGHLC
what resists IR at 90 degrees abduction
anterior and posteior band IGHLC
what resists inferior translation at 0 degrees abduction
SGHL
coracohumeral lig
what resists inferior translation at 90 degrees abduction
IGHLC
what is a loose/open packed position for the GH joint
55 degrees abduction
30 degrees horizontal adduction
what is a close packed position
end range abduction and ER
what is the ER convex-concave rule
roll posterior
glide anterior
what is the IR convex-concave rule
roll anterior
glide posterior
what is the flexion convex-concave rule
roll superior
glide inferior
what does the rotator cuff do
pulls head of humerus into glenoid fossa
what does the deltoid do
- large stabilizing component, regardless of humeral position
- primary function to swing humerus
what is subacromial impingement
-RTC tendon and/or LHB may get repeadetdly compressed, along with bursa
potential causes:
- RTC dysfunction
- scapular positioning
- shape of acromion
- GH joint mobility deficit or hypermobility
