Shoulder Ligaments and Structures Flashcards
Sternoclavicular joint type
Synovial ball and socket joint
clavicular head w/ clavicular notch of manubrium
Sternoclavicular disk
- 3 functions
Fibrocartilage, from superior head of clavicle to lateral inferior clavicular notch
- Increase congruence
- Decrease compressional stress
- Prevents superior translation of clavicle head
Anterior and posterior sternoclavicular ligaments
capsular
1. limit anterior and posterior mvt of clavicle head
Interclavicular ligament
Capsular, Between clavicular heads, also binds to manubrium
1. Prevents lateral translation of clavicle
Costoclavicular ligament
Extrinsic, from inferior medial clavicle to costal cartilage and 1st costal bone
1. Prevents superior translation of clavicle head
Acromioclavicular joint
- Type and function
Synovial gliding joint, planar
1. Increases ROM of scapulae
Superior and inferior acromioclavicular ligament
Capsular
1. Prevent superior translation of clavicle
Coracoclavicular ligament
Extrinsic, from coracoid tubercle of clavicle to coracoid process of scapula
2 parts- trapezoid most lateral, conoid (twisting) more medial
1. Prevent superior translation of clavicle
Shoulder separation definition
Luxation/subluxation of acromioclavicular joint
Lateral blow to shoulder forces lateral clavicle upward
The acromioclavicular joint is most important for which movement?
Elevation/depression of scapula
(Upward rotation of clavicle but no rotation of scapula, not possible if fused)
- AC joint increases ROM in all planes
Post/ant tilt ROM
Anatomical position is almost as posteriorly tilted as possible (inf angle resting on thorax)
- Ant tilt- 30-35º, inferior angle moves off thorax
Scapular movements in sagittal, frontal, transverse planes
Sagittal: ant/post tip
Frontal: elevation/depression, up/down rotation (AoR med inf scapular spine)
Transverse: protract/retract, axis longitudinal through SC joint
Glenoid Labrum
- Increase congruency
2. Decrease stress by increasing SA
Axillary recess- definition, significance
Inferiorly sagging part of GH joint capsule
Weakest part, MOI for subluxations
Coracohumeral Ligament
3 fx
From coracoid process to greater and lesser tuberosities (2 bands, crosses bicipital groove)
- Limits inferior translation
- Limits Adduction
- Helps protect biceps tendon
Coracoacromial Ligament
Coracoid process to acromion
Extrinsic, forms roof of coracoacromial arch
1. Limits superior mvt humerus
Glenohumeral ligaments (3 parts)
Capsular, all anterior
Superior: ER, post translation, Adduction
Middle: ER
Inferior: ER, Ant translation, ABDuction
Transverse ligament of humerus
Crosses bicipital groove
1. Supports bicipital tendon
Scapulohumeral Rhythm in ABD
Total ROM 160-180, approximately 2:1 mvts
90º pure GH ABD
60º Scapular up rotation
30º additional ROM with external rotation
(clears greater tubercle, provides articular surface)
Scapulohumeral coupled motions
- GH flexion + elevation, slight post tip
- Horiz ABD + retraction
- ABD + up rotation, elevation
And vice versa
Supraspinatus and subacromial bursa
Bursitis damages supraspinatus muscle & tendon, impingement
Rotator Cuff tear MOI
Usually supraspinatus tendon calcifies under pressure
Evulsion- tendon rupture, tear
Subacromial bursitis can impinge it
Common with overhead work
Superior transverse scapular ligament
From superior angle to base of coracoid process, spans scapular notch
- suprascapular artery passes above
- suprascapular nerve passes below/through notch
