Muscles of the posterior forearm Flashcards
What is the main action of the muscles in the posterior forearm?
Extension
How many layers of muscles are there in the posterior forearm?
Two; superficial and deep
What nerve innervates all the muscles in the posterior forearm?
The radial nerve
How many muscles are in the superficial layer?
7
Which muscles are in the superficial layer?
Brachioradialis Aconeus Extensor carpi radialis longus Extensor carpi radialis brevis Extensor carpi ulnaris Extensor digiti minimi Extensor digitorum
What is the main action of the Brachioradialis?
Flexion at the elbow!*
What does the Brachioradialis cover?
Radial artery
Radial nerve
What innervates the Brachioradialis?
Radial nerve
What is the postition of the Extensor carpi radialis brevis to the Extensor carpi radialis longus?
Deep
What is the main action of the Extensor carpi radialis longus/brevis?
Extension at the wrist
Abduction at the wrist
What innervates the Extensor carpi radialis longus/brevis?
The radial nerve
What is the main action of the Extensor digitorum?
Extends the fingers at the metacarpophalangeal joint and interphalangeal joint
What innervates the Extensor digitorum?
The radial nerve
What is the main action of the Extensor digiti minimi?
Extends the little finger
Contributes to extension at the wrist
What innervates the Extensor digiti minimi?
The radial nerve
Where is the Extensor carpi ulnaris?
On the medial side of the posterior forearm
What are the main actions of the Extensor carpi ulnaris?
Extension at the wrist
Adduction at the wrist
What nerve innervates the Extensor carpi ulnaris?
The radial nerve
Where is the Aconeus muscle?
Most medial in the forearm
Its fibres blend with the tendon of the Triceps brachii
What is the main action of the Aconeus muscle?
Moves the Ulna during pronation
Extends at the elbow joint
What innervates the Aconeus muscle?
The radial nerve
What is wrist drop a sign of?
Radial nerve damage
What is wrist drop?
Unopposed flexion as all the extensor muscles are paralysed
How many muscles are in the deep compartment of the posterior forearm?
5
What are the muscles in the deep compartment of the posterior forearm?
Supinator Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Extensor indicis
What is special about the Supinator muscle?
Has 2 heads with the radial nerve running between the 2
What innervates the Supinator muscle?
The radial nerve
What is the main action of the Supinator muscle?
Supination of the forearm
Where is the Abductor pollicis longus?
Distal to the Supinator
Lateral side of the forearm
What is the main action of the Abductor pollicis longus?
Abducts the thumb
What innervates the Abductor pollicis longus?
Radial nerve
Where is the Extensor pollicis brevis?
Medial and deep to Abductor pollicis longus
What is the main action of the Extensor pollicis brevis?
Extends the Metacarpophalangeal joint of the thumb
Extends the CarpoMetacarpel joint of the thumb
What innervates the Extensor pollicis brevis?
The radial nerve
What is the main action of the Extensor pollicis longus?
Extends all joints of the thumb
What innervates the Extensor pollicis longus?
The radial nerve
What does the Extensor indicis allow?
The index finger to be independent of the other fingers during extension
What innervates Extensor indicis?
The radial nerve
What is the main action of Extensor indicis?
Extension of the index finger
