Shoulder/ glenohumeral joint Flashcards
Name/ classification
Synovial ball and socket joint
Movement
Flexion
Extension
Abduction
Adduction
Medial rotation
Lateral rotation
Horizontal abduction
Horizontal adduction
Degrees of freedom/ planes of movement
3 degrees of freedom in the sagittal, transverse and frontal plane.
Bones and articulating surfaces
Head of humerus
Glenoid fossa of scapula
Cartilage
Hyaline cartilage at articulating surfaces reduces friction and is a shock absorber.
Glenoid labrum offsets joint.
Joint capsule
Attached to articular margins
Is loose inferiorly so allows considerable mobility
Posteriorly and inferiorly, capsular insertion is directly onto labrum. Superiorly, it includes origin of long head of biceps tendon
Capsule is reinforced by rotator cuff muscles and ligaments
Synovial membrane
Lines the capsule and secretes synovial fluid which nourishes cartilage, removes waste and reduces friction.
Ligaments=
- Glenohumeral ligaments (superior, middle and inferior), they limit external rotation and translation of humeral head, help hold the proximal humerus in the glenoid fossa of the scapula.
- Coracoacromial ligament- stabilizes the humeral head during overhead movements.
- Coracoclavicular ligaments- attach inferior distal clavicle to the caracoid processes of the scapula.
- Sternoclavicular ligaments- anchors medial end of clavicle to manubrium of sternum.
- Transverse humeral ligament
Blood supply
Branches of subclavian and axillary arteries
Nerve supply
Branches of:
Suprascauplar
Axillary
Subscapular
Lateral pectoral
Musculocutaneus
Muscles (flexion)
Deltoid
Pectoralis major
Biceps brachii
Coracobrachialis
Muscles (extension)
Deltoid
Latissimus dorsi
Teres major
Pectoralis major
Triceps brachii
Muscles (adduction)
Coracobrachialis
Pectoralis major
Latissimus dorsi
Teres major
Muscles (abduction)
Deltoid
Supraspinatus
Muscles (medial rotation)
Subscapularis
Teres major
Latissimus dorsi
Pectoralis major
Deltoid
