1. JOINTS OF THE UPPER LIMB WINDSOR UNIVERSITY SCHOOL OF MEDICINE

2. JOINTS CLASSIFICATION OF JOINTS Three classes of joints are described, based on the manner or type of material by which the articulating bones are united. 1. SYNOVIAL JOINTS are united by a joint (articular) capsule (composed of an outer fibrous layer lined by a serous synovial membrane) spanning and enclosing an articular cavity The joint cavity of a synovial joint contains a small amount of lubricating synovial fluid, secreted by the synovial membrane. Internal surfaces are covered by synovial membrane.

4. 2. FIBROUS JOINTS: The sutures of the cranium are examples of fibrous joints These bones are close together, either interlocking along a wavy line or overlapping. A syndesmosis type of fibrous joint unites the bones with a sheet of fibrous tissue, either a ligament or a fibrous membrane. This type of joint is partially movable E.g. 1. The interosseous membrane in the forearm is a sheet of fibrous tissue that joins the radius and ulna in a syndesmosis 2. A dento-alveolar syndesmosis (gomphosis or socket) articulation between the root of the tooth and the alveolar process of the jaw.

6. 3. Cartilaginous joints are united by hyaline cartilage or fibrocartilage. Primary cartilaginous joints permit growth in the length of a bone. When full growth is achieved, the epiphysial plate converts to bone and the epiphyses fuse with the diaphysis(temporary unions). Secondary cartilaginous joints, or symphyses, are strong, slightly movable joints united by fibrocartilage.

7. SYNOVIAL JOINTS, the most common type of joint, provide free movement between the bones they join; they are joints of locomotion, typical of nearly all limb joints. The six major types of synovial joints are classified according to the shape of the articulating surfaces and/or the type of movement they permit. They are:

8. 1. Plane joints permit gliding or sliding movements in the plane of the articular surfaces. The opposed surfaces of the bones are flat or almost flat, with movement limited by their tight joint capsules. Plane joints are numerous and are nearly always small. Eg acromioclavicular joint between the acromion of the scapula and the clavicle. 2. Hinge joints permit flexion and extension only, movements that occur in one plane (sagittal) uniaxial joints. The joint capsule of these joints is thin and lax anteriorly and posteriorly where movement occurs; however, the bones are joined by strong, laterally placed collateral ligaments. e.g. elbow joint

9. 3. Saddle joints permit abduction and adduction as well as flexion and extension, biaxial joints that allow movement in two planes, sagittal and frontal. The performance of these movements in a circular sequence (circumduction) is also possible. The Carpometacarpal joint at the base of the 1st digit (thumb) is a saddle joint. 4. Condyloid joints permit flexion and extension as well as abduction and adduction; thus condyloid joints are also biaxial. However, movement in one plane (sagittal) is usually greater (freer) than in the other. The metacarpophalangeal joints (knuckle joints) are condyloid joints.

10. 5. Ball and socket joints allow movement in multiple axes and planes: flexion and extension, abduction and adduction, medial and lateral rotation, and circumduction; thus ball and socket joints are multiaxial joints. The hip joint is a ball and socket joint in which the spherical head of the femur rotates within the socket formed by the acetabulum of the hip bone. 6. Pivot joints permit rotation around a central axis; thus they are uniaxial. In these joints, a rounded process of bone rotates within a sleeve or ring. The median atlantoaxial joint is a pivot joint in which the atlas (C1 vertebra) rotates around a finger-like process, the dens of the axis (C2 vertebra), during rotation of the head.

12. JOINT VASCULATURE AND INNERVATION Joints receive blood from articular arteries that arise from the vessels around the joint. The arteries often anastomose (communicate) to form networks (peri- articular arterial anastomoses) to ensure a blood supply to and across the joint Articular veins are communicating veins that accompany arteries (L.venae comitantes) and, like the arteries, are located in the joint capsule, mostly in the synovial membrane.

13. anastomosis

14. Joints have a rich nerve supply provided by articular nerves with sensory nerve endings in the joint capsule. In the distal parts of the limbs (hands and feet), the articular nerves are branches of the cutaneous nerves supplying the overlying skin. The Hilton law states that the nerves supplying a joint also supply the muscles moving the joint and the skin covering their distal attachments.

15. Degenerative Joint Disease Synovial joints are well designed to withstand wear, but heavy use over several years can cause degenerative changes. Degenerative joint disease or osteoarthritis is often accompanied by stiffness, discomfort, and pain. Osteoarthritis is common in older people and usually affects joints that support the weight of their bodies (e.g., the hips and knees).

16. Arthroscopy The cavity of a synovial joint can be examined by inserting a cannula and an arthroscope (a small telescope) into it. orthopedic surgeons use this to examine joints for abnormalities, such as torn menisci (partial articular discs of the knee joint).

17. Avascular necrosis Loss of arterial supply to an epiphysis or other parts of a bone results in the death of bone tissue— avascular necrosis (G. nekrosis, deadness). After every fracture, small areas of adjacent bone undergo necrosis. In some fractures, avascular necrosis of a large fragment of bone may occur

18. Upperlimb joints

19. Type Articulation Ligaments Movements

20. Glenohumeral Joint SHOULDER JOINT TYPE: ◦ Synovial : ball and socket joint Bony articulation ◦ -Head of the Humerus ◦ -Glenoid cavity of the Scapula ◦ (deepened by Glenoid labrum)

22. Important Relation Anteriorly Subscapularis, Axillary vessels, Brachial plexus Posteriorly Infraspinatus, Teres minor Superiorly Supraspinatus, Subacromial Bursa Coracoacromial lig., Deltoid m. Inferiorly Long head of Triceps, Axillary n Post.circumflex humeral artery.

24. Contain thin layer of synovial fluid Located where tendons rub against bone, ligaments, or tendons and when skin moves over bone directly beneath Subscapular bursa Subacromial (subdeltoid) bursa Bursa of Shoulder Joint

25. Subscapular bursa ◦ Between tendon of subscapularis muscle and neck of scapula ◦ Communicates with cavity of shoulder joint Subacromial (subdeltoid) bursa ◦ Between deltoid, supraspinatus tendon and glenohumeral capsule ◦ Does not communicate with cavity of shoulder ◦ Facilitates movement of deltoid over joint capsule and supraspinatus tendon under coracoacromial arch

26. Movements: Mobile but unstable joint - The head of the humerus doesn’t fit perfectly with the glenoid fossa and Glenoid labrum

27. FLEXION Pectoralis Major Deltoid m.(anterior.fibres) Biceps Coracobrachialis EXTENSION * Latissimus Dorsi * teres Major * Triceps –long head

28. ABDUCTION Deltoid m.(mid.fibres) Supraspinatus m. ADDUCTION Pectoralis major, Latissimus Dorsi, Teres Major LATERAL ROTATION. Infraspinatus, Teres minor Deltoid (post. fibres) MEDIAL ROTATION. Subscapular, Latisimus Dorsi Deltoid (ant. fibres)

29. Stability Depends mainly on Rotator cuff muscles, deltoid & biceps muscles The weakest part is the inferior aspect of the capsule( no muscles)

30. ANTERIOR DISLOCATION Shoulder joint is the most commonly dislocated large joint  Common type is anterior dislocation (post. Dislocation is very rare)  Young adult(athletes)  Excessive extension and lateral rotation of the humerus  Head of the humerus comes to lie inferior to the glenoid fossa  Head is pulled (by flexors and adductors of the shoulder joint) forward And upward into the subcoracoid position

31. ANTERIOR DISLOCATION

32. Elbow Joint TYPE: Hinge type of synovial joint ARTICULATIONS : Trochlea and spheroidal capitulum of the humerus articulate with the trochlear notch of the ulna and the slightly concave superior aspect of the head of the radius

33. CAPSULE : The fibrous layer of the joint capsule surrounds the elbow joint. The synovial membrane lines the internal surface of the fibrous layer of the capsule and the intracapsular non- articular parts of the humerus.

34. Ligaments of the Elbow Joint Lateral: Radial collateral ligament extends from the lateral epicondyle of the humerus and blends distally with the anular ligament of the radius. Medial: Ulnar collateral ligament extends from the medial epicondyle of the humerus to the coronoid process and olecranon of the ulna.

35. Movements of the Elbow Joint Flexion and extension occur at the elbow joint. Chief flexors of the elbow joint are the brachialis and biceps brachii. Chief extensor of the elbow joint is the triceps brachii.

36. Bursae around the Elbow Joint 1. Intratendinous olecranon bursa 2. Subtendinous olecranon bursa 3. Subcutaneous olecranon bursa

37. Bursitis of the Elbow Student's elbow: Subcutaneous olecranon bursa is exposed to injury during falls on the elbow and to infection from abrasions of the skin covering the olecranon.

38. Tennis elbow(Lateral epicondylitis) It occurs at the common extensor tendon that originates from the lateral epicondyle. The acute pain that a person might feel occurs as one fully extends the arm.

39. Golfer's elbow(medial epicondylitis) Is an inflammatory condition of the medial epicondyle of the elbow.

40. Proximal radioulnar joint Type: Pivot type of synovial joint Articulation: Head of the radius articulates with the radial notch of the ulna Ligaments: The strong anular ligament, attached to the ulna anterior and posterior to its radial notch.

41. Movements Pronation and supination. Pronation: Pronator quadratus (primarily) and pronator teres Supination: Supinator and biceps brachii.

42. Subluxation and Dislocation of Radial Head Pulled elbow or Nursemaid's elbow The sudden pulling of the upper limb tears the distal attachment of the anular ligament, where it is loosely attached to the neck of the radius.

43. Wrist Joint (radiocarpal) Type: Condyloid (ellipsoid) type of synovial joint Articulation: The ulna does not participate in the wrist joint. The distal end of the radius articulate with the proximal row of carpal bones, except for the pisiform.

44. Movements of the Wrist Joint Flexion, extension, abduction and adduction (radial deviation and ulnar deviation).

45. Muscles Moving the Wrist Joint

46. Tendon Reflexes Deep Tendon Reflexes will not work if either the sensory or motor component of the nerve to the muscle being tested are injured, or if the spinal cord segment where the reflex is integrated is injured.

47. 47 Hypo reflex – problem in Nerves or Roots Hyper Reflex – Problem in Spinal cord or Brain Technique : Patient sitting and relaxed. Therapist places her thumb over biceps tendon and applies a brisk tap (to her thumb nail) with reflex hammer Biceps jerk

48. 48 Triceps Jerk It is initiated by the Cervical spinal nerve 7 nerve root ( C7)