Muscles of Forearm Flashcards
What is the origin of superficial muscles of the anterior compartment of the forearm?
medial epicondyle = common flexor origin
What are the superficial muscles of the anterior compartment of the forearm?
pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris
What is the additional origin of pronator teres apart from the CFO?
medial aspect of coranoid process of ulna
What is the insertion of pronator teres?
midpoint of the radius
What is the insertion of flexor carpi radialis?
base of the 2nd and 3rd metacarpals
What is the action of flexor carpi radialis?
flexion at the wrist and radial deviation
What is the insertion of palmaris longus?
blends with the palmar aponeurosis - doesn’t go through the carpal tunnel
What is the additional origin of flexor carpi ulnaris apart from the CFO?
extensive aponeurotic attachment to the border of the ulna
What is the insertion of flexor carpi ulnaris?
the base of the 5th metacarpal with pisiform in the tendon
What muscle makes up the intermediate layer of the anterior compartment of the forearm?
flexor digitorum superficialis
What is the origin of flexor digitorum superficialis?
CFO, coronoid process and comprehensive attachment to the radius and ulna shafts with a fibrous arch between
What is the insertion of flexor digitorum superficialis?
splits into 4 tendons and each tendon inserts on the base of the middle phalynx with a split to allow tendons of FDP through
What muscles make up the deep layer of the anterior compartment of the forearm?
flexor digitorum profundus, flexor pollicis longus and pronator quadratus
What is the origin of flexor digitorum profundus?
the shaft of the ulna and the adjacent part of the interosseus membrane
What is the insertion of flexor digitorum profundus?
splits into 4 tendons which insert on the base of the distal phalynx by going through FDS tendons
What is the origin of flexor pollicis longus?
the shaft of the radius and the adjacent part of the inteosseus membrane
What is the insertion of flexor pollicis longus?
base of the distal phalynx of the thumb
What is the origin of pronator quadratus?
the distal portion of the ulna
What is the insertion of pronator quadratus?
the distal portion of the radius
What is the attachments of the flexor retinaculum?
scaphoid, trapezium, hook of hamate, pisiform
In what order to the tendons go through the carpal tunnel?
4 tendons of FDP go through on the bottom, then the tendons of the 2nd and 5th fingers of FDS, then the tendons of the 3rd and 4th fingers of FDS with the tendon of FPL
What nerve goes through the carpal tunnel?
median nerve
Which tendon has its own tunnel under the flexor retinaculum?
flexor carpi radialis
What are the groups of muscles that make up the extensor compartment of the forearm?
3 ‘radialis’ muscles, 3 posterior aspect muscle, 3 ‘thumb’ muscles splitting them and 3 other deep muscles
What are the 3 ‘radialis’ muscles?
brachioradialis, extensor carpi radialis longus and extensor carpi radialis brevis
What are the 3 posterior aspect muscles?
extensor digitorum, extensor digiti minimi and extensor carpi ulnaris
What are the 3 ‘thumb’ muscles?
abductor pollicis longus, extensor pollicis brevis and extensor pollicis longus
What are the 3 other deep muscles?
supinator, anconeus and extensor indicis
What is the common extensor origin?
the lateral epicondyle of the humerus
What muscles originate at the CEO?
extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi and extensor carpi ulnaris
What muscles originate from the supracondylar ridge above the CEO?
brachioradialis and extensor carpi radialis longus
What is the insertion of brachioradialis?
styloid process of the radius
What is the action of brachioradialis?
it is actually a flexor at the elbow even though its in the extensor compartment
What is the insertion of extensor carpi radialis longus and extensor carpi radialis brevis?
base of the 2nd and 3rd metacarpal
What is the action of extensor carpi radialis longus and brevis?
extension and radial deviation
What is the insertion of extensor digitorum?
splits into 4 tendons and each tendon splits into 3 insertion on the base of the middle phalanx and base of the distal phalynx
What is special about extensor digit minimi?
its belly splits off of extensor digitorum so it has its own tendon
What is the insertion of extensor carpi ulnaris?
base of the 5th metacarpal
What is the action of extensor carpi ulnaris?
extension and ulnar deviation
What is the difference between extensor pollicis longus and brevis?
extensor pollicis longus take the long way around - it goes beneath the extensor retinaculum before inserting on to the thumb
How can you find supinator?
It’s the muscle encircling the proximal shaft of the radius
Which nerve passes through the two heads of supinator?
radial nerve
How many tunnels are there created by the extensor retinaculum?
6
