Elbow And Forearm Flashcards
Describe the articulations are in the elbow joint
Humeroulnar joint: Between Trochlea of humerus and Trochlear/ Sigmoid notch of Ulna
Humeroradial joint: Between Capitellum of humerus and Radius head
Describe the Proximal Radio-Ulnar joint
Where is it found?
Is it part of the elbow joint
Between side of Radial head and Radial Notch of Ulna
Found within joint capsule of elbow
Not part of elbow joint
What muscle groups attach to the Medial and Lateral Epicondyles of the Humerus
Medial Epicondyle: Flexor-Pronator muscle groups in anterior forearm
Lateral Epicondyle: Extensor muscle groups in posterior forearm
During elbow flexion, what do the Coronoid and Radial Fossae accommodate
During elbow extension, what does the Olecranon Fossa accommodate
Coronoid fossa accommodates the Coronoid Process of Ulna
Radial fossa accommodates the Radial head
Accommodates the tip of the Olecranon
Why is the radial neck susceptible to fracture
It’s thin
Describe the attachments of the Radial Collateral Ligament
What is its function
Attaches Lateral Epicondyle of humerus to Annular Ligament of Radius (with which it blends)
Keeps head of radius and capitellum close together during pronation/ supination
Describe the attachments of the Ulnar Collateral Ligament
What are the 3 bands
Which is strongest and weakest
Which one deepens the socket
Attaches Medial Epicondyle of Humerus to Coronoid process and Olecranon of Ulna
Anterior band: Strongest
Posterior band: Weakest
Inferior/ Oblique band: Deepens socket for trochlea of humerus
Which ligament stabilises the Proximal Radioulnar joint
How does it do this?
Annular ligament
Forms a collar around Radial Head, so that it can rotate whilst maintaining contact with radial notch of ulna
What is the Carrying Angle?
How much is it normally in men and women
The Valgus angle between between the Ulna and and long axis of Humerus (Made in full extension of ulna)
Women: 10-15 degrees
Men: 5-10 degrees
Compare Cubitus Valgus and Cubitus Varus
Cubitus Valgus: Excessive carrying angle
Cubitus Varus: Carrying angle that deviates towards body (e.g -5 degrees)
What are 3 major muscles that flex the elbow
Brachialis
Biceps brachii
Brachioradialis
At which 2 joints does Pronation and Supination occur
Which muscles do Supination;
- In absence of resistance to movement
- With resistance to movement
Proximal and distal Radio-Ulnar joints
In absence of resistance to movement: Supinator
With resistance: Biceps brachii
Describe the Olecranon Bursa and Subtendinous Bursa in elbow
Olecranon Bursa;
- Between olecranon and overlying subcutaneous tissue
Subtendinous Bursa;
- Between Triceps Brachii tendon and tip of olecranon
Describe how the Ulnar notch of the Radius rotates around Head of Ulna during Pro/ Supination
Ulnar notch of radius rotates anteriorly around Head of Ulna
What Fibrocartilaginous articular disc binds the radius and ulna together distally
The TFCC (Triangular fibrocartilage complex)
Other than Proximal and Distal Radio-Ulnar joints, describe a fibrous joint connecting the 2 bones together
What are 2 functions of this structure?
Interosseus membrane runs diagonally from radius proximally to ulna distally
- Keeps bones together during Pronation/ Supination
- Prevents proximal displacement of radius if a force is applied to outstretched hand
Name the 3 Posterior arm muscles that affect the elbow
Name all the muscles of Anterior compartments/ sub-compartments of forearm
Remember “4-1=3” for anterior compartment
Posterior;
- Brachioradialis
- Supinator
- Anconeus
Anterior Superficial; (pass/fail/pass/fail)
- Flexor carpi ulnaris
- Palmaris longus
- Flexor carpi radialis
- Pronator teres
Anterior Intermediate;
- Flexor digitorum superficialis
Anterior Deep;
- Flexor digitorum profundus
- Flexor pollicis longus
- Pronator quadratus
List the 4 muscles of Anterior Superficial Forearm Laterally to Medially
Describe their origin
- Flexor carpi ulnaris
- Palmaris longus
- Flexor carpi radialis
- Pronator teres
Originate from the COMMON FLEXOR ORIGIN (a single tendon) from the Medial Epicondyle of the Humerus
State the Origins and Insertions of Flexor carpi ulnaris (FCU)
Origins;
- Humeral head: Common Flexor Origin from Medial Epicondyle
-Ulnar head: Medial aspect of Olecranon
Insertion;
- Pisiform bone, Hook of hamate and Base of Metacarpal 5
State the Actions and Innervation of Flexor carpi ulnaris (FCU)
Actions: Flexion and Adduction of Wrist
Innervation: Ulnar nerve
State the Insertion of Palmaris Longus (PL)
Is this muscle present in everyone?
Insertion: Flexor retinaculum of wrist and Palmar aponeurosis
Not always present (Absent in 15% of population)
State the Actions and Innervation of Palmaris Longus (PL)
What is the surgical result of this?
Innervation: Median nerve
Actions: (Very weak) wrist flexor, can be harvested for use in tendon grafting
Describe how to check if you have Palmaris Longus (PL)
Flex wrist and oppose thumb and little finger
PL tendon will protrude in midline
State the Insertion, Innervation and Action of Flexor carpi radialis (FCR)
Insertion: Base of Metacarpals 2-3
Innervation: Median nerve
Action: Flexion and Adduction of wrist
State the Origins and Insertions of Pronator teres
Origins;
- Humeral head: Common Flexor Origin from Medial Epicondyle
- Ulnar head: Coronoid process of Ulna
Insertion: (Passes laterally to) Insert onto mid-shaft of Radius
State the Innervation and Action of Pronator teres
Innervation: Median nerve
Action: Pronation of forearm
State the Origins and Insertion of Flexor digitorum superficialis (FDS)
Origins;
- Humeroulnar head: Common Flexor Origin, Ulnar Collateral Ligament, Coronoid Process
- Radial head: Anterior surface of radius
Insertion: (Base of) Middle phalanges of fingers 2-5
State the Actions and Innervation of Flexor digitorum superficialis (FDS)
Actions;
- Assists with flexion of wrist
- Flexion of MCP Joints of fingers 2-5
- Flexion of PIP joints of fingers 2-5
Innervation: Median nerve
State the Origin and Insertions Flexor digitorum profundus (FDP)
Origin: Proximal 2/3rds of Ulnar shaft, Interosseus membrane
Insertions: (Base of) Distal phalanages of fingers 2-5
State the Actions and Innervations of Flexor digitorum profundus (FDP)
Actions;
- Flexion of DIP joints of fingers 2-5
- Flexion of MCP joints of fingers 2-5
- Assists in wrist flexion
Innervation;
- Ulnar/ Medial half: Ulnar nerve
- Radial/ Lateral half: Anterior interosseus branch of Median nerve
Which fingers are innervated by the;
- Ulnar half of Flexor digitorum profundus (FDP)
- Radial half of Flexor digitorum profundus (FDP)
- Ulnar half- Little and ring fingers
2. Radial half- Index and middle fingers
State the Origins and Insertions of Flexor pollicis longus (FPL)
Origin: Interosseus membrane, Anterior surface of middle of radial shaft
Insertion: (Base of) Distal phalanx of thumb
State the Actions and Innervation of Flexor pollicis longus (FPL)
Actions;
- Flexion of IP Joint of thumb
- Flexion of MCPJ joint of thumb
Innervation;
- Anterior interosseus branch of median nerve
State the Origin, Insertion, Action and Innervation of Pronator Quadratus
Origin: Anterior surface of distal ulna
Insertion: Anterior surface of distal radius
Action: Pronates forearm
Innervation: Anterior interosseus branch of median nerve
State the Origin and Insertion of Brachioradialis
Origin: Proximal aspect of Lateral Supracondylar ridge of humerus
Insertion: Distal end of radius
State the Innervation and Action of Brachioradialis
Innervation: Radial nerve
Action;
- Elbow flexion (Most effective when forearm is mid-prone)
- Assist flexion in supinated position
State the Origins and Insertion of Supinator
Origins;
- Humeral head: Common Extensor Origin on lateral epicondyle of humerus
- Ulnar head: Supinator crest on lateral border of proximal shaft of ulna
Insertion: Proximal lateral surface of radius
State the Innervation and Action of Supinator
Action: Supinates forearm (Mainly when resistance is absent)
Innervation: Deep branch of radial nerve
State the Origins and Insertion of Anconeus
Origin: Common Extensor Origin
Insertion: Lateral side of Olecranon, Posterior surface of proximal ulna
State the Innervation and 3 Actions of Anconeus
Innervation: Radial nerve
Actions;
- Weak extensor of elbow, assists triceps
- Stabilises elbow joint
- During Pronation, abducts ulna and prevents joint capsule from impingement within olecranon fossa
Outline the motor and sensory functions of the Median nerve
Motor function: Innervates Flexor, Pronator muscle in Anterior forearm (except FCU and ulnar half of FDP)
Sensory function: Radial aspect of palm, radial 3.5 fingers on palmar surface and Dorsum of their respective distal phalanges
Which Median nerve branches supply the;
- radial aspect of palm
- radial 3.5 fingers+ dorsum of distal phalanges
Palm: Palmar cutaneous branch of median nerve
Fingers: Digital cutaneous branch of median nerve
The median nerve is initially lateral to brachial artery.
Describe its path into the anterior forearm
- Halfway down arm, crosses over becoming medial to brachial artery
- Enters anterior forearm via cubital fossa
Outline the path of Median nerve from Cubital fossa into hands
- Exits cubital fossa by travelling between Pronator Teres heads, deep to tendinous arch of FDS
- Passes distally between FDS and FDP
- Gives off Anterior Interosseus and Palmar Cutaneous Branch
- Enters hand via carpal tunnel, gives off 2 branches (Recurrent, Palmar Digital)
FDS is a useful anatomical landmark. What 2 structures pass through its 2 heads
Median nerve
Ulnar artery
Outline the motor and sensory functions of the Ulnar nerve
Motor: Innervates intrinsic muscles of hand, FCU and ulnar half of FDP
Sensory: Innervates Palmar+Dorsal surfaces of Ulnar 1.5 fingers, and Ulnar aspect of Pam+Dorsum
Outline the path of the Ulnar nerve from elbow into anterior forearm
- At elbow, passes posterior to medial humeral epicondyle in the cubital tunnel
- Passes between 2 heads of FCU to enter forearm, travels deep to FCU
What 3 branches does the Ulnar nerve give off in the forearm
Muscular branch: (FCU and Ulnar half FDP)
Palmar cutaneous branch: (Ulnar 3rd of palm)
Dorsal cutaneous branch: (Dorsal surface of ulnar 1.5 fingers +dorsum)
Outline the pathway of Ulnar nerve from wrist into hand
- At wrist, travels medially to ulnar artery
- Enters hand via Ulnar/ Guyon’s canal
- In hand, terminates into superficial and deep branches
what is Froment’s sign
Describe it
A test for ulnar nerve palsy (Specifically paralysis of adductor pollicis)
- Patient asked to grab paper between thumb and index finger, as paper pulled away
- If normal, thumb Adduction should hold paper in place
- If positive test, can’t adduct thumb. Instead, they flex the thumb at IPJ to hold paper in place
Where does the Superficial branch of ulnar nerve arise?
What does it Innervate
Arises in palm
Innervates Ulnar 1.5 fingers (Via palmar digital nerves)
Outline the motor and sensory functions of the Musculocutaenous nerve
Motor: Anterior arm muscles (BBC)
Sensory: Lateral forearm (Now called the Lateral Cutaneous Nerve)
Describe the path of the MSC Nerve from the Plexus to the Elbow
- Emerges from brachial plexus at inferior border of Pec Minor
- Pierces Coracobrachialis near its insertion (Giving a branch to it)
- Passes down anterior arm, between Biceps and Brachialis (Giving them each a branch)
- Perces deep fascia lateral to Biceps, emerging laterally to Biceps and Brachialis
Describe the path of the MSC Nerve from the Elbow to forearm
Which vein can it be found close to in this region?
- Enters forearm as the Lateral Cutaneous Nerve
Cephalic vein
MSC nerve damage is protected in Axilla, so is uncommon
What are 3 mechanisms of injury
- Post shoulder dislocation
- Injury during shoulder surgery
- Penetrating trauma to axilla (Stabbing)
Outline the effects of MSC Nerve damage on Motor and Sensory function
Motor;
- Paralysis of BBC muscles
- Weakened elbow+shoulder flexion (Pec major and Brachialis allow function)
- Weakened supination (Supinator allows function)
Sensory: Loss of sensation over lateral forearm
What is the small branch of the Brachial Plexus?
What nerve root fibres does it have
What does it innervate
Medial cutaneous nerve of the arm, T1 fibres
Skin of distal anterior surface of medial arm, extending as far as the elbow
What nerves fibres are in Medial Cutaenous Nerve of Forearm?
What does it Innervate?
C8 and T1
Skin on distal anterior surface of arm and medial forearm, extending as far as wrist
How are the Radial and Ulnar arteries formed? Where?
Which parts of the forearm are supplied by each?
Which arteries branch off of the Ulnar artery
Bifurcation of brachial artery, in cubital fossa
Radial artery: Posterolateral forearm
Ulnar artery: Anteromedial forearm
Ulnar artery gives rise to Common Interosseus artery-> Ant and Post Interosseus arteries
Where can you measure the;
- Brachial pulse
- Radial pulse
- Ulnar pulse
Brachial pulse: In cubital fossa, medial to Biceps tendon
Radial pulse: At wrist, lateral to FCR tendon
Ulnar pulse: At wrist, lateral to FCU tendon and proximal to pisiform bone
Compare the 2 common variants of the Superficial veins in the upper limb
- Cephalic and Basilic vein connected by Median Cubital Vein
- Basilic vein branches-> Median Basilic vein
- Cephalic vein branches-> Median Cephalic vein
- Median Basilic and Median Cephalic veins connected by Median Vein of Forearm
What veins form the deep venous system of upper limb?
How are the Deep and Superficial venous systems connected?
Venue comitantes (Paired veins that lie on either side of an artery)
Deep and superficial veins connected by Perforating veins
What is the Cubital Fossa?
What are its 3 borders?
A triangular depression anterior to elbow joint
Lateral border: Brachioradialis
Medial border: Pronator teres
Superior border: Imaginary line between Humeral Epicondyles
What makes up the Floor and Roof of Cubital Fossa?
What reinforces the Cubital Fossa roof?
What 3 things run within the roof?
Floor;
- Proximal floor: Brachialis
- Distal floor: Supinator
Roof;
- Skin and fascia, reinforced by Bicipital Aponeurosis
Median cubital vein, Medial cutaenous nerve, Lateral cutaneous nerve run within the roof
State the content of the Cubital Fossa, Laterally to Medially
Really Need Beer To Be At My Nicest
Really Need: Radial nerve
Beer To: Biceps tendon
Be At: Brachial Artery
My Nicest: Median nerve
Identify the muscles in the (5) Deep and (7) Superficial Posterior Forearm (laterally to Medially)
Superficial;
- Brachioradialis
- Extensor carpi radialis longus (ECRL)
- Extensor carpi radialis brevis (ECRB)
- Extensor Digitorum (ED)
- Extensor digiti minimi (EDM)
- Extensor carpi ulnaris (ECU)
- Anconeus
Deep;
- Supinator
- Abductor pollicis longus (APL)
- Extensor pollicis brevis (EPB)
- Extensor pollicis longus (EPL)
- Extensor indicis (EI)
Which 4 Posterior Superficial muscles of forearm share a common origin?
What is the origin called? Where is it?
- Extensor carpi radialis brevis (ECRB)
- Extensor Digitorum (ED)
- Extensor digiti minimi (EDM)
- Extensor carpi ulnaris (ECU)
Common Extensor Origin, at Lateral Humeral Epicondyle
Which 2 fingers do the Deep Posterior Forearm muscles act on?
Which muscle in this group is an exception
Thumb and index finger
Supinator
State the Origin, Insertion, Innervation and Actions of Extensor carpi radialis longus (ECRL)
Origin: Lateral Supracondylar Ridge of humerus
Insertion: Dorsal surface of base of Metacarpal 2
Innervation: Radial nerve
Actions: Abduction and Extension of Wrist
State the Origin, Insertion, Innervation and Actions of Extensor carpi radialis brevis (ECRB)
Origin: Common Extensor Origin
Insertion: Dorsal surface of Base of Metacarpal 3
Innervation: Deep branch of radial nerve (radial nerve already divided before perforating the muscle)
Actions: Extension and Abduction of Wrist
State the Origin, Insertion, of Extensor Digitorum (Communis)
How are the 4 tendons of this muscle connected?
What is the significance of this?
Origin: Common Extensor Origin
Insertion: Extensor hood of fingers 2-5
Juncturae tendinum (Fibrous bands on the dorsum)
This connection prevents full extension of middle/ ring finger, if other fingers are flexed
State the Innervation and Action of Extensor Digitorum (Communis)
Innervation: Posterior interosseus branch of radial nerve
Action: Extension of fingers at MCP and IP joints
How do you test the function of Action of Extensor Digitorum (Communis)
When forearm is pronated, extend fingers against resistance
State the Origin, Insertion, Innervation and Actions of Extensor Digiti Minimi (quinti proprius)
Origin: Common Extensor Origin
Insertion: Extensor hood of little finger
Innervation: Posterior interosseus branch of radial nerve
Action: Extension of little finger, assists wrist extension
State the Origins and Insertion of Extensor carpi ulnaris (ECU)
Origins;
- Humeral head: Common Extensor Origin
- Ulnar head: Olecranon, Posterior Proximal Ulna and Deep fascia
Insertion: Base of metacarpal 5
State the Innervation and Actions of Extensor carpi ulnaris (ECU)
Innervation: Posterior interosseus branch of radial nerve
Actions: Adduction and extension of wrist
State the Origins, Insertion, Innervation and Actions of Abductor pollicis longus (APL)
(APL is immediately distal to Supinator)
Origin: Interosseus membrane, Posterior radius and ulna
Insertion: (Lateral side of base of) Metacarpal 1
Innervation: Posterior interosseus branch of radial nerve
Action: Thumb abduction, assists in Carpometacarpal joint extension
State the Origins, Insertion, Innervation and Action of Extensor pollicis longus (EPL)
Origin: Interosseus membrane, Middle 1/3 of posterior ulna
Insertion: Distal phalanx of thumb
Innervation: Posterior interosseus branch of radial nerve
Action: Thumb extension
State the Origins, Insertion, Innervation and Action of Extensor pollicis brevis (EPB)
Origin: Interosseus membrane, posterior radius
Insertion: (Base of) Proximal phalanx of thumb
Innervation: Posterior interosseus branch of radial nerve
Action: Thumb extension
State the Origins, Insertion, Innervation and Action of Extensor indicis (EI)
Origin: Interosseus membrane, posterior ulna (Distal to EPL)
Insertion: Extensor hood of index finger
Innervation: Posterior interosseus branch of radial nerve
Action: Index finger extension
Outline the Motor and Sensory functions of the Radial Nerve
Motor: Triceps and Extensor muscles in forearm
Sensory;
- Posterior arm
- Lower lateral arm
- Posterior forearm
- Dorsal surface of radial side of hand
- Dorsal surface of radial 3.5 digits (Except distal phalanges)
Outline the pathway of the radial nerve from posterior upper arm to lower arm
- In posterior arm, gives off branches to;
- Long+Lateral Triceps heads
- Posterior Cutaneous nerve of the arm - Goes down radial groove of humerus, gives off branches to; - Medial Triceps head
- Lower Lateral Cutaneous Nerve of Arm
- Posterior Cutaneous Nerve of Forearm
Outline the path of the Radial Nerve as it runs through and exits the Cubital Fossa
What is it now called?
- Through the cubital fossa, runs anteriorly to lateral epicondyle
- In cubital fossa, branches into Superficial and Deep branches
- Exits cubital fossa by passing posteriorly between heads of supinator (Which it innervates).
It is now called the Posterior Interosseus Nerve
