Week 5 - The Posterior Compartment of the Forearm Flashcards
Which muscles make up the superficial compartment of the posterior forearm?
Brachioradialis Extensor carpi radialis Extensor digitorum Extensor digiti minimi Extensor carpi ulnaris Anconeus
Which muscles make up the deep muscles of the posterior forearm?
The supinator Abductor pollicis longus Extensor pollicis longus Extensor pollicis brevis Extensor indicis
What separates the deep muscles from the superficial muscles in the posterior compartment of the forearm?
A layer of fascia
What is the action of brachioradialis?
Flexes at the elbow, especially when the forearm is pronated.
It is the beer-drinking muscle!
What are the actions of extensor carpi radialis?
Extension of the hand at the wrist
Abduction of the hand at the wrist
What is the action of extensor digitorum?
Extends the 4 fingers at the MCP and IP joints
What is the action of extensor digiti minimi?
Extends the little finger at the MCP and IP joints
What are the actions of extensor carpi ulnaris?
Extends the hand at the wrist
Adducts the hand at the wrist
Why is the supinator an important anatomical landmark? (2 reasons)
Makes up the floor of the cubital fossa
Deep branch of the radial nerve runs between its two heads
What is the action of the supinator?
Supinates the forearm
What are the actions of abductor pollicis longus?
Abducts the thumb
Extends the thumb at the CMC joint
What is the action of extensor pollicis brevis?
Extends the thumb at CMC and MCP joints
What is the action of extensor pollicis longus?
Extends the thumb at all 3 joints - CMC, MCP and IP
What is the action of extensor indicis?
Extends the index finger at all joints
What nerve innervates all the muscles in the posterior compartment of the forearm, and what are its nerve roots?
The radial nerve, C5, C6, C7, C8, T1
