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