The shoulder joint (dave's notes) Flashcards
What type of joint is the shoulder?
Synovial joint of ball and socket variety
What is the ratio of head to cavity? What increases this ratio?
4:1. The Glenoid labrum, a fibrocartilage ring, deepens the cavity.
What are the attachments of the shoulder joint capsule?
The scapula, the margins of the labrum, and head of the humerus except inferiorly (neck)
What happens to the shoulder joint capsule at the upper end of the inter tubercular groove??
The capsule bridges the gap, forming the transverse humeral ligmament
Describe the shoulder joint capsule
The capsule is thick and strong, but lax. It is thickened at the humerus by muscular tendons
What are the attachments of the synovial membrane? With what does the synovium communicate?
Attached around the glenoid lsabrum and lines the capsule and head/neck of the humerus. Communicates with the sup scapular bursa.
What are the ligaments of the shoulder joint?
Coracohumeral: running from under surface of coracoid to the greater tuberosity
Coracoacromial: strong and increases the supporting surface. Separated from the rotator cuff by the subacromial bursa
What is the bursa of the shoulder?
The subacromial (sub deltoid) bursa lies beneath and normally does not connect (with what?)unless there is a tear of supraspinatus
What provides the stability of the shoulder joint?
Stability is provided with muscles and scapular tendons.
The tendons of supraspinatus, infraspinatus, and teres minor attach close and fuse with the lateral capsule, = rotator cuff.
What happens to the long head of biceps?
It sinks through the capsule and is intracapsular
What does fracture of the labrum result in?
Disclocation
What prevents upward displacement?
The coracoacromial arch which is very strong
What are the movements of the shoulder joint?
Abduction from anatomical position is to about 90’, this is increased with lateral rotation to 120’, remainder from scapula. Flexion is free. About 90’ of lateral rotation is available and 70’ of medial rotation.
