Session 9 Part 1 Flashcards
Two articulations of elbow joint
Humeroulnar joint - trochlear of humerus and trochlear notch of ulnar
Humeral radial joint- capitellum of humerus and radial head
What is proximal radio-ulnar joint
Between side of head of radius and radial notch of ulna
Within joint capsule- not part of elbow joint
What do the 2 distal humerus condyles do
Support articular elements- trochlea and capitellum
What do the 2 distal humeral epicondyles do
Serve as attachment for muscles of the forearm
What does the medial epicondyle provide attachment for
Flexor-Pronator group of muscles in the anterior forearm
What does the lateral epicondyle provide attachment for
Extensor group in the posterior forearm
What happens to the elbow joint during flexion
Radial and coronoid fossa of humerus accommodate the radial head and coronoid process of ulna
What happens at elbow extension
On posterior distal humerus, olecranon fossa receives tip of olecranon
Radial tuberosity is site of insertion for what
Biceps brachii
What does the ulna sigmoid notch articulate with
Trochlea of distal humerus
What is the olecranon posteriorly the site of insertion for
Triceps brachii
What does the radial notch of the ulna articulate with
Radial head
The supinator crest is the site of origin for what
Ulner head of supinator muscle
lateral aspect of elbow joint capsule strengthened by
Radial (lateral) collateral ligament
Fan shaped structure attached between lateral epicondyle of humerus and annular ligament of radius
Keeps head of radius and capitellum in close association during pronation and supination
Medial aspect of elbow joint strengthened by
Ulnar (medial) collateral ligament
Triangular ligament, stretches between medial epicondyle of humerus and coronoid process and olecranon of Ulna
Consists of 3 bands- anterior (strongest), posterior (fan-like, weak), and slender oblique (inferior) band which deepens socket for trochlea of humerus
Proximal radioulnar joint is stabilised by
Annular ligament - forms collar around the radial head within which it can rotate whilst maintaining contact with radial notch of ulna
It is a pivot joint
In full extension the ulna makes a
Valgus angle (lateral)
Carrying angle: 5-10 in men and 10-15 in women
What does the carrying angle do
Permits the forearm to clear the hips in swinging movements of the arm during walking
Xs= cubitus valgus
Not enough = cubitus varus
Major muscles that flex the elbow
Brachialis
Biceps brachialis
Brachioradialis
Major extensor of elbow joint
Triceps brachii
Anconeus is weak
Supination and pronation occur at the
Proximal and distal radio-ulnar joints
What performs supination and pronation
Supination = supinator or biceps brachii if resistance
Pronation = Pronator quadratus and Pronator teres
2 important bursae around elbow joint
Olecranon bursa and subtendinous bursa
What does subcutaneous olecranon bursa do
Lies in subcutaneous connective tissue overlying the olecranon
Reduce friction
What does the subtendinous bursa do
Lies between triceps tendon and tip of olecranon
Reduce friction
What is distal radio-ulnar joint
Pivot joint in which ulnar notch of radius rotates anteriorly around head of ulnar
What binds the radius and ulnar together and also separates the distal radioulnar joint from wrist joint
Triangular fibrocartilage complex
Muscles producing supination and pronation at distal radio ulnar joint (same as at proximal)
Supinator in absence of resistance or biceps brachii
Pronator quadratus and Pronator teres
What is the interosseous membrane
Forms a fibrous joint between radius and ulna- keeps bones together during pronation and supination and prevents proximal displacement of the radius if force is applied to outstretched hand
Way to remember muscles of anterior forearm
4-1 = 3
What does 4-1 = 3 mean
4 = superficial
Position thumb on medial epicondyle, 4 superficial flexors, pass fail pass fail
Pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris
What does 1 stand for
Middle- flexor digitorum superficialis
What does 3 stand for
Deep
Flexor digitorum profundus, flexor pollicis longus, Pronator quadratus
Where do the superficial muscles of the anterior forearm arise from
Medial epicondyle of the humerus
Common flexor origin
What is immediately deep to the palmaris longus
Median nerve
How does the deep branch of the radial nerve exit the cubital fossa
Passing between 2 heads of supinator to enter posterior compartment of forearm
Where does the superficial branch of the radial nerve pass
Superficial to supinator, deep to brachioradialis
Anatomical course of median nerve
Descends arm lateral to brachial artery
Crosses and becomes medial halfway down arm
Enters anterior arm via cubital fossa
Exits between Pronator teres 2 heads
Passes distally between flexor digitorum superficialis and profundus
Anatomical course of ulnar nerve to the wrist
Descends medial aspect of arm
At elbow, passes posterior to the medial epicondyle of the humerus in cubital tunnel
Passes between 2 heads of flexor carpi ulnaris to enter forearm and travels deep
3 branches of ulnar nerve in forearm
Muscular branch
Palmar cutaneous branch
Dorsal cutaneous branch
Ulnar nerve at wrist
Superficial to flexor retinaculum and medial to ulnar artery
Enters hand via ulnar canal (Guyon’s canal)
Terminates by giving rise to superficial and deep branches
What is froment’s sign
Test for ulnar nerve palsy
Paralysis of adductor pollicis
Grasp a piece of paper with thumb and index finger whilst being pulled away
Positive test = patient unable to adduct the thumb
Anatomical course of musculocutaneous nerve
Leaves axilla and pierces Coracobrachialis muscle
Down flexor compartment superficial to brachialis but deep to biceps brachii
Pierces deep fascia lateral to biceps brachii to emerge lateral to biceps tendon and brachioradialis
Continues as lateral cutaneous nerve of forearm
Mechanisms of injury to musculocutaneous nerve
Stabbing, anterior dislocation, injury during shoulder surgery
Radial artery supplies
Posterolateral aspect of Forearm
Ulnar artery supplies
Anteromedial aspect of forearm
Gives rise to anterior and posterior interosseous arteries supplying deeper structures
How do radial and ulnar arteries anastomose
In the hand by forming 2 arches, the superficial palmar arch and the deep palmar arch
Brachial pulse can be palpated at the
Cubital fossa median to tendon of biceps brachii
Radial pulse can be palpated at the
Wrist immediately lateral to prominent tendon of flexor carpi radialis
Ulnar pulse can be palpated
At the wrist, lateral to tendon of flexor carpi ulnaris and proximal to pisiform bone
The superficial veins are considered to form
Part of the root of cubital fossa
Borders of cubital fossa
Medial border of brachioradialis
Lateral border of Pronator teres
Hypothetical line between epicondyles of humerus
Floor and roof of cubital fossa
Floor = Brachialis and supinator muscle
Roof = skin and fasciae, reinforced by bicipital aponeurosis
What runs within the roof of cubital fossa
Medial cubital vein, accessed for venupuncture
Medial and lateral cutaneous nerves of forearm
Contents of cubital fossa from lateral to medial
Radial nerve, biceps tendon, brachial artery, median nerve
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All muscles of the anterior forearm are supplied by the
Median nerve with the exception of flexor carpi ulnaris and ulnar half of flexor digitorum profundus (ulnar nerve)
How to remember muscles of posterior forearm
3 x 3 x 3+ 3
3x muscles to wrist
3x muscles to fingers
3x muscles to thumb
+3 random
All innervated by radial nerve
3x muscles to wrist
Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor carpi ulnaris
3x muscles to fingers
Extensor digitorum, extensor digiti minimi, extensor indicis
3x muscles to thumb
Abductor pollicis longus, extensor pollicis longus, extensor pollicis brevis
+3 muscles posterior
Anconeus, supinator and brachioradialis
