Welcome Everybody To My Presentation On Shoulder joint

1. Welcome Everybody To My Presentation On Shoulder joint

2. Introduction • It is a ball and socket type of synovial joint • It is a multiaxial spheroidal jt • Roughly hemispheric head of the humerus form the ball and shallow glenoid fossa of scapula form the socket. • Skeletally jt is weak. It depends for stability and support on it’s surrounding muscle rather than it’s shape and ligaments. • Only one third of humeral head is in contact with the glenoid fossa at any time.

6. Angle of inclination: in the frontal plane, the axis of the head and neck of humerus form an angle of 130°-140° with the long axis of shaft of femur.Because of this angulation, the centre of the humeral head lies about 1cm medial to the long axis. • Angle of retroversion:an angle to the shaft of the humerus, the axis of the head and neck is rotated backwords against the shaft some 30°-40°, this is caled the angle of retroversion.

9. Articular surface • Two articular surface: • Glenoid fossa: • glenoid fossa is situated at the supero-lateral angle of the scapula • faces laterally, anteriorly and slightly superiorly. • Concavity of glenoid fossa is irregular and less deep than convexity of head of the humerus. • The articular surface the fossa is little more than the head of the humerus • It ls covered by hyaline cartilage • Hyaline cartilage is thinner centrally and thickest peripharally

11. Head of the humerus: • It represents two-fifths of a sphere • It faces superiorly, medially and anteriorly • Covered by hyaline cartilage • On the humerus hyaline cartilage is thickest centrally and thinner peripherally

13. Joint capsule • It is like a cylindrical sleeve and situated between two bones • Majority fibres of the capsule passes horizontally between scapula and humerus. But some oblique and transversre fibres are also found • On the scapula, the capsule attaches just outside the glenoid labrum anteriorly and inferiorly • On the humerus, capsile attaches to the anatomical neck,medial to the greater and lesser tubercle

15. Continuation • Anterior part of the capsule is thickened and strengthened by three glenohumeral ligaments. • Superoposterior part is strengthened by coracohumeral ligament • In anatomical position of the arm the lower part of the capsule is lax and forms a redundant fold. • In abduction of arm lower part become s taut

17. Continuation • It is supported by the: • supraspinatus (above) • Infraspinatus and teres major (behind) • Subscapularis (in front) • Long head of triceps (below) • Capsule has two or three openings: • Below the coracoid process • Between two tubercles • Inbursa undea the infraspinatous tendon

19. Synovial membrane • This lines the capsule and covers parts of the anatomical neck • The synovial membrane is reflected from the margin of the glenoid cavity over the labrum • The tendon of the long head of the Biceps brachii passes through the capsule and is enclosed in a tubular sheath of synovial membrane

21. Glenonoid labrum • It is lintra-articular structure • It is a fibro-cartiliginous rim round the glenoid fossa • It is triangular in section • 4mm deep • It’s base attaches to the margin of the glenoid fossa. • Outer surface attaches to the joint capsule superiorly and posteriorly • Inner surface is in the contact of head of humerus • It protects the joint and assists lubrication

23. Capsular Ligaments • Glenohumeral ligament: • Superior glenohumeral ligament: • It is splender shaped • It arises from upper part of the glenoid labrum • It runs laterally parallel to the biceps tendon to the upper tendon to the upper surface of the lesser tubercle

24. Middle glenohumeral ligament: • Arises from below the superior glenohumeral ligament • Attaches to the humerus on the front of the lesser tubercle below the insertion of subscapularis

25. Inferior glenohumeral ligamrent: • It is best developed of the three ligaments • It arises from the anterior border of the glenoid labrum • It descends slightly obliquely to the anteroinferior part of the anatomical neck • The antero-superior edge of the inferior ligament is thickened and known as superior band • The thickening of the anterior part of the capsule to which inferior ligament attaches is known as axillary pouch

29. Function of glenohumeral ligament: • They have no stabilizing function • Lateral rotation of the humerus put all three ligaments under tension • Medial rotation relaxes them • In abduction only the middle and inferior ligament become taut and superior ligament become relaxed

30. Transverse humeral ligament: • It is formed by some of the transeverse fibres of the capsule • At the upper end of the intertubercular groove, the transverse humeral ligamentbridges the gap between the greater and lesser tubercles. • It hold the biceps tendon in the intertubercular groove.

33. Intra- articular ligament These ligaments are considered as accessory ligament • Coracohumeral ligament: • It is strong and broad • It arises from the lateral border of the coracoid process near its root. • It passes laterally above the intertubercular groove to attach to the anatomical neck to the greater and lesser tubercle • Anterior part of the ligament is free. But laterally it fuses with the tondon of subscapularis • It inserted in lesser tubercle

35. Coracoacromial ligament: • It is not directly associated with the joint • It is a strong and triangular ligament • It forms with the coracoid and acromion process, a fibro- osseous arch above the head of the humerus • Its anterior and posterior part is thicker than intermediate part.

38. Bursae • between the subscapular tendon and articular capsule • Sometimes between the infraspinatous tendon and capsule • Subacromial bursa: between deltoid and capsule. • On the superior acromial aspect • Between coracoid process and capsule • Sometimes behind coracobrachialis • Between teres major and the long head of biceps

41. Muscle • Deltoid (anterior fibre): • Origin:Arises from the anterior border and upper surface of the lateral third of the clavicle • Insertion: • Function:

42. Deltoid (middle fibres): • Origin:Arises from the lateral margin and upper surface of the acromion. • Insertion: • Function:

43. Deltoid (posterior fibre): • Origin:Arises from the lower lip of the posterior border of the spine of scapula, as far back as the triangular surface at its medial end. • Insertion: • Function:

47. Pectoralis major: • Origin: • Insertion; • Function: