upper limb bones and joints Flashcards
articulation of the clavicle
lateral side: articulates with acromion
medial side: articulates with manubrium of sternum and first costal cartilage
parts of the scapula (superior to inferior)
suprascapular notch, coracoid process, supraspinous fossa, acromion, spine of scapula, glenoid cavity, infraspinous fossa
winged scapula cause
C5, 6, 7 raise my wings to heaven: injury of the long thoracic nerve (C5-7) weakens the serratus anterior –> the scapula is no longer held against the thoracic wall –> medial border moves laterally and posteriorly
dropped scapula cause
paralysed trapezius due to spinal accessory nerve (CN XI) damage
movements of the scapula + muscles
elevation: trapezius, levator scapulae
protraction/abduction: serratus anterior, pectoralis
upward rotation: trapezius, serratus anterior
depression: trapezius, pectoralis minor
retraction/adduction: trapezius, rhomboid
downward rotation: levator scapulae, rhomboid
fracture of the humerus locations and impact
SAX, SHARD, SUPRAMED, MEEPUL
surgical neck (weakest point) fracture: axillary nerve lesion
shaft fracture: radial nerve lesion
supracondylar fracture: median nerve lesion
medial epicondyle fracture: ulnar nerve lesion
parts of humerus (superior to inferior)
head, anatomical neck, greater tubercle, lesser tubercle + intertubercular groove, surgical neck, radial groove, deltoid tuberosity, medial supracondylar ridge + medial epicondyle, lateral supracondylar ridge + lateral epicondyle, radial fossa, coronoid fossa, olecranon fossa, capitulum, trochlea
parts of radius
- head, neck, shaft
- radial tuberosity
- styloid process
- articular surface for carpal bone
- interosseous border
parts of ulna
- trochlear notch
- olecranon process
- coronoid process
- shaft, head, styloid process
- interosseous border
carpal bones
Some Lovers Try Positions That They Cannot Handle:
scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, hamate
carpal bone fractures (and impact)
hook of hamate fracture: due to FOOSH
scaphoid fracture: causes avascular necrosis of bone due to disrupted flow of recurrent branches of radial artery
no. of hand bones
8 carpal bones
5 metacarpal bones
14 phalanges
joints in the upper limb
- scapulohumeral
- acromioclavicular
- sternoclavicular
- carpometacarpal
- interphalangeal
- elbow and wrist joints
types of joints (3)
fibrous joint: articulating surfaces of the bones united by fibrous tissue
cartilaginous joint: bones are united by hyaline or fibrocartilage
synovial joint: articulating surfaces of the bones are covered in hyaline cartilage and separated by joint cavity
types of synovial joint + example (7)
- plane/gliding (intervertebral joint)
- hinge (elbow joint)
- ball and socket (shoulder joint)
- pivot (proximal radio-ulnar joint)
- condyloid (metacarpophalangeal joint)
- ellipsoid (wrist joint)
- saddle (carpometacarpal joint)
glenohumeral joint components
head of humerus + glenoid cavity of scapula + glenoid labrum (neck) + ligaments (glenohumeral, coracohumeral, transverse humeral) + fibrous capsule lined by synovial membrane + extra security from muscles (Subscapularis, Supraspinatus, Infraspinatus, Teres minor)
factors adding to the stability of the glenohumeral joint
- bony: fibrocartilaginous glenoid labrum
- muscular: rotator cuff muscles
- ligament: coracoacromial, coracohumeral, glenohumeral and transverse humeral ligaments
- joint capsule
movements (and muscles involved) at the glenohumeral joint
- flexion: deltoid, pectoralis major, biceps brachii, coracobrachialis
- extension: deltoid, latissimus dorsi, teres major, triceps brachii
- medial rotation: subscapularis, pectoralis major, latissimus dorsi, teres major, deltoid
- lateral rotation: infraspinatus, teres minor, deltoid
- abduction: supraspinatus (0-15°), serratus anterior (120-180°)
- adduction: subscapularis, teres minor, triceps brachii (+ pectoralis, subclavius and latissimus dorsi for scapula rotation)
innervation of the glenohumeral joint
Hilton’s law: sensory nerves supplying the joint also supply the muscles and skin around it
innervation: axillary nerve (C5, C6), suprascapular nerve (C5, C6)
blood supply of the glenohumeral joint
arterial anastomoses between branches of the subclavian and axillary arteries
anterior dislocation of the glenohumeral joint cause and impact
cause: sudden violence to the fully abducted humerus, tearing the inferior weakest part of the capsule –> humeral head is pulled by muscles anterosuperiorally into a subcoracoid position
impact: injury of axillary nerve –> paralysis of deltoid and numbness over deltoid skin area, injury of radial nerve, supraspinatus muscle tear
posterior dislocation of the glenohumeral joint cause and impact
cause: direct violence to the front of the joint
impact: shoulder isn’t round anymore (greater tuberosity doesn’t bulge beneath the deltoid), axillary and radial nerve may be injured –> brachial palsy
frozen shoulder pathogenesis
connective tissue surrounding the glenohumeral joint of the shoulder becomes inflamed and stiff, restricting motion and causing chronic pain
articulations making up the elbow joint
humeroulnar joint, humeroradial joint, proximal radio-ulnar joint
factors contributing to the stability of the elbow joint
- bony: olecranon process of ulna –> olecranon fossa of humerus
- muscular: extension limited by brachialis and anterior ligament
- ligaments: strong collateral, lateral and annular ligaments
- joint capsule: tight hinge joint
- bursa: flexion limited by surface of arm and forearm
movements (and muscles involved) of the elbow joint
- flexion: biceps, brachialis, brachioradialis
- extension: triceps
- pronation: pronator teres, pronator quadratus
- supination: supinator
tendonitis of the elbow pathogenesis (2)
- golfer’s elbow due to overuse of common flexor tendon from the medial epicondyle of the humerus
- tennis elbow due to overuse of the common extensor tendon from the lateral epicondyle of the humerus
dislocation of the elbow causes
posterior dislocation: if FOOSH with flexed elbows, causing subluxation of radial head from ulnar ligament –> anterior fat pad sign on x-ray
uncommon though!
components of the wrist joint
distal end of the radius w scaphoid and lunate bones, articular disc covering the head of the ulna w lunate and triquetrum, radius styloid process
factors adding to the stability of the wrist joint (3)
- bones: shaping the articular surfaces into an ellipsoid joint shape
- capsule: encloses joint
- ligaments: palmar radiocarpal, radial collateral, ulnar collateral
movements (and muscles required) of the wrist (4)
- flexion: flexor carpi radialis, flexor carpi ulnaris, flexor digitorum superficialis, flexor digitorum profundus, flexor pollicis longus, palmaris longus
- extension: extensor carpi radialis, extensor carpi ulnaris, extensor digitorum, extensor indicis, extensor digiti minimi, extensor pollicis longus
- abduction: flexor carpi radialis, extensor carpi radialis, abductor pollicis longus, extensor pollicis longus, extensor pollicis brevis
- adduction: flexor carpi ulnaris, extensor carpi ulnaris
wrist fracture types and causes (3)
- distal wrist fracture: FOOSH
- scaphoid fracture: FOOSH with the wrist extended and abducted
- anterior dislocation of the lunate: FOOSH on the dorsiflexed wrist causing carpal tunnel syndrome
components of the carpometacarpal joint (of the thumb)
trapezium, base of the first metacarpal
movements (and muscles involved) of the carpometacarpal joint (6)
- flexion: flexor pollicis brevis, opponens pollicis
- extension: extensor pollicis longus, extensor pollicis brevis
- abduction: abductor pollicis longus, abductor pollicis brevis
- adduction: adductor pollicis
- opposition: opponens pollicis
movements (and muscles involved) of the carpometacarpal joint (5)
- flexion: flexor pollicis brevis, opponens pollicis
- extension: extensor pollicis longus, extensor pollicis brevis
- abduction: abductor pollicis longus, abductor pollicis brevis
- adduction: adductor pollicis
- opposition: opponens pollicis
