Glenohumeral Joint Flashcards
Joint classification, how the joint achieve stability, movements and muscles, innervation and blood supply, what can go wrong and how to tell on examination.
Classify the joint according to structure and function.
Structure - synovial joint; function - ball and socket joint.
What are the articulating surfaces of the glenohumeral joint?
Glenoid cavity of scapula + head of humerus.
How is stability achieved in the glenohumeral joint?
Glenoid labrum, joint capsule, ligaments, rotator cuff muscles, biceps tendon.
What are the ligaments of the glenohumeral joint?
Glenohumeral ligaments, coracohumeral ligament, transverse humeral ligament, coracoclavicular ligament, coracoacromial ligament.
Where is the glenohumeral ligament and what is its role?
From humerus to glenoid fossa, prevents anterior dislocation by supporting anteriorly.
Where is the coracohumeralligament and what is its role?
Base of coracoid process to greater tubercle of humerus, supports superiorly.
Where is the transverse humeral ligament and what is its role?
Between two tubercles of humerus, holds tendon of long head of the biceps in intertubercular groove.
Where is the coracoclavicular ligament?
From clavicle to coracoid process.
Where is the coracoacromial ligament and what is its role?
Acromion and coarcoid process to make coracoacromial arch so prevent superior dislocation.
What are the rotator cuff muscles?
Subscapularis, supraspinatus, infraspinatus, teres minor.
What are the actions of the glenohumeral joint?
Flexion, extension, abduction, adduction, internal rotation, external rotation.
What are the muscles powering flexion of the glenohumeral joint?
Deltoid, latissimus dorsi, teres major.
What are the muscles powering extension of the glenohumeral joint?
Pectoralis major, anterior deltoid, caroacobrachialis.
What are the muscles powering abduction of the glenohumeral joint?
0-15 degrees - supraspinatus
15-90 degrees - middle deltoid
90+ degrees - serratus anterior and trapezius to rotate scapula
What are the muscles powering adduction of the glenohumeral joint?
Pectoralis major, latissimus dorsi, teres major.
What are the muscles powering internal rotation of the glenohumeral joint?
Subscapularis, pectoralis major, latissimus dorsi, teres major, anterior deltoid.
What are the muscles powering external rotation of the glenohumeral joint?
Infraspinatus, teres minor.
Which arteries supply the glenohumeral joint?
Anterior and posterior circumflex humeral arteries, suprascapular artery, branch of thyrocervical trunk.
Which nerves innervate the glenohumeral joint?
Axillary, suprascapular, lateral pectoral nerves.
What is impingement syndrome?
Thickening of coracacromial ligament which leads to impingement.
What is the mechanism of injury resulting in anterior glenohumeral dislocation?
Excessive extension and external rotation of humerus.
What is a complication of glenohumeral anterior dislocation?
Axillary nerve damage leading to deltoid paralysis and loss of sensation over the regimental badge area.
What is rotator cuff tendonitis?
Inflammation of muscle tendons due to overuse leading to degenerative changes.
What is painful arc syndrome?
Pain on abduction between 60-120 degrees.
