Shoulder - Joints & Ligaments Flashcards
Sternoclavicular joint type
Diarthorodial (synovial)
Saddle shape
Sternoclavicular joint ligaments
Interclavicular lig
Ant and post SC ligs
Costoclavicular lig
Acromioclavicular joint type
Diarthorodial (synovial)
Acromioclavicular joint ligaments
Sup and inf AC ligs
EXTRAARTICULAR – Coracoclavicular ligs (conoid and trapezoid)
Glenohumeral joint capsule ligaments
Glenohumeral ligs (sup, middle inf) – inferior GH lig is split into [ant, post and axillary pouch]
EXTRAARTICULAR – Coracohumeral lig
Glenohumeral joint capsule origin and insertion
Origin: glenoid rim
Insertion: anatomic neck of humerus
Superior glenohumeral ligament actions
primary restraint to ER in adducted or slightly abducted position
primary restraint to inferior translation
secondary restraint to posterior translation
Superior glenohumeral ligament origin and insertion
Origin: upper pole of glenoid and base of coracoid
Insertion: superior to lesser tuberosity
Middle glenohumeral ligament action
prevents ant translation at 45° abduction
secondary restraint of ER at 90° abduction
Inferior glenohumeral ligament action
primary restraint to abduction at 90° (anterior band)
primary restraint to IR (posterior band)
Inferior GH lig origin and insertion
Origin: glenoid inf to MGHL
Insertion: inferior aspect of anatomic neck
Coracohumeral lig action
primary restraint to inf translation in adducted position
Coracohumeral lig origin and insertion
O: base of coracoid process
I: sup to greater tuberosity with attachment to capsule
Coracoacromial lig action
limit superior humeral translation
*important with impingement syndrome
Coracoacromial lig origin and insertion
O: sup lat coracoid process
I: acromion, anterior to ACJ
stability of the shoulder joint relies primarily on
static and dynamic structures
scapulohumeral rhythm
2:1
ligaments, joint capsule, labrum
static or dynamic
static
skeletal mm
static or dynamic
dynamic
the shoulder complex consists of 4 joints
glenohumeral
sternoclavicular
acromioclavicular
scapula-thoracic articulation
the shoulder complex is made up of what 4 bones
sternum
clavicle
scapula
humerus
Acts as a “strut” holding the GHJ away from the body to allow full ROM
Clavicle
Only direct joint connection of the upper extremity to the trunk
sternoclavicular joint
Strongest portion of the sternoclavicular ligament
posterior
Prevents superior, anterior & posterior displacement
sternoclavicular ligament
Strengthens the shoulder capsule superiorly; limits superior displacement
Interclavicular ligament
Helps increase stability & shock absorption
articular disc of acromioclavicular joint
Static stabilizers of glenohumeral joint (4)
- Glenoid labrum
- Joint capsule
- Glenohumeral ligaments
- Coracohumeral ligament
Origin: glenoid inferior to SHGL
Insertion: anterior aspect of anatomic neck of humerus
middle glenohumeral ligament
“roof” of the shoulder joint
coracoacromial ligament
Sternoclavicular joint is reinforced by what 2 ligaments
- Costoclavicular lig
- Interclavicular lig
Function of SCJ
• increases stability
• provides shock absorption
• anchors inferior surface of sternal end of the clavicle to first rib
• opposes pull of SCM
Costoclavicular ligament
Anterior & posterior SC ligament is reinforced with the
SCM tendon
ACJ has major stability from ____ and ____ AC ligaments
Reinforced by the attachment ____ and ____ muscles
Superior and inferior AC ligaments
Deltoid and trapezius muscles
• important in stability and motion
• anchor the clavicle to the coracoid process
Coracoclavicular ligaments
What ligament counteracts the pull of the pectoralis minor and coracobrachialis
Coracoacromial ligament
