shoulder: bones and joints

What is the only bony connection of the shoulder girdle to the axial skeleton?

clavicle

Clavicle: shape

medially: concave posteriorly

laterally: concave anteriorly

Clavicle: landmarks

acromial end (flat), conoid tubercle (acromial end), sternal end

Clavicle: fractures

80% middle third, 15% distal third, 5% proximal third

Clavicle: MOI

lateral fall on shoulder, FOOSH

Sternoclavicular joint: type

multiraxial arthrodial joints

Sternoclavicular joint: ligament support

interclavicular, sternoclavicular, costoclavicular

Sternoclavicular joint: motions

protraction/retraction, elevation/depression, modest rotation

Interclavicular ligament: connection

clavicle to clavicle (1)

Sternoclavicular ligament: connection

sternum to clavicle (4)

Costoclavicular ligament: connection

clavicle to 1st rib (2)

Articular disc: composition

fibrocartilage

Acromioclavicular joint: type

multiaxial gliding joint

Acromioclavicular joint: ligament support

acromioclavicular, coracoclavicular, coracoacromial

Coracoacromial ligament: function

protective hood to prevent humerus from hitting clavicle

Coracoclavicular ligament: made up of

trapezoid (lateral) and conoid (medial) ligaments

Acromioclavicular sprain: MOI

posteriorly directed force on scapula, FOOSH

(can also involve coaracoacromial ligament)

What is the difference between shoulder dislocation and shoulder separation?

dislocation- head of humorous pops out of glenoid cavity

separation- ligament sprain, results in clavicle abnormality

Glenohumeral jount: type

multiaxial diarthrodial

Aricular capsule

thin sac that envelops joint, doesn’t offer much stability

Genohumeral joint: ligament support

coracohumeral, glenohumeral

Coracohumeral ligament: connection

coracoid process to greater tubercle

Glenohumeral ligament: connection

end of glenoid fossa and lesser tubercle (anterior, posterior, inferior)

Glenoid labrum

fibrocartilage around rim of glenoid fossa, deepend and enlarges socket

Rotator cuff muscles

supraspinatus, infraspinatus, teren minor, subscapular

Rotator cuff impingement

muscles get squeezed under arch of clavicle and scapula

Glenohumeral joint: motions

flexion/extemsion, abduction/adduction, internal/external rotation, horizontal abduction/adduction

Motions of scapula

elevation/depression, protraction/retraction, upward/downward rotation (all frontal)