Posterior Extensor Compartment of the Forearm Flashcards
Layers of the Posterior Compartment?
Superficial
Deep
General common origin of extensor muscles?
Lateral Epidcondyle of the Humerus
Muscles in the Superficial Compartment
Brachioradialis Extensor Carpi Radialis Longus Extensor Carpi Radialis Brevis Extensor Digitorum Extensor Carpi Ulnaris Extensor Digiti Minimi Anconeus
Muscles in the Deep Compartment
Supinator Extensor Pollicis Longus Extensor Pollicis Brevis Abductor Pollicis Longus Extensor Indicis
Function of Brachioradialis
Accessory flexor during mid pronation despite being in the posterior extensor compartment!
Origin of Brachioradialis
Lateral Supraepicondylar Ridge
Adjacent Intermuscular Septum
Insertion of Brachioradialis
Lateral Distal Radius
Innervation of Brachioradialis
Radial Nerve
Function of Extensor Carpi Radialis Longus
Extends and abducts the wrist
Origin of Extensor Carpi Radialis Longus
Supraepicondylar ridge
Adjacent Intermuscular Septum
Insertion of Extensor Carpi Radialis Longus
Base of Metacarpal 2
Innervation of Extensor Carpi Radialis Longus
Radial Nerve
Function of Extensor Carpi Radialis Brevis
Extends and abducts the wrist
Origin of Extensor Carpi Radialis Brevis
Lateral Epicondyle
Adjacent Intermuscular Septum
Insertion of Extensor Carpi Radialis Brevis
Base of Metacarpals 2 and 3
Innervation of Extensor Carpi Radialis Brevis
Radial Nerve (deep branch)
Function of Extensor Digitorum
Extensor of Digits 2-5 (and wrist)
Origin of Extensor Digitorum
Lateral Epicondyle
Adjacent Intermuscular Septum and Deep fascia
Insertion of Extensor Digitorum
Middle and Distal Phalanges of Digits 2- 5 via Extensor Hoods
Innervation of Extensor Digitorum
Posterior Interosseous Nerve
continuation of deep branch of radial nerve
Function of Extensor Digiti Minimi
Accessory extension of Digit 5
Origin of Extensor Digiti Minimi
Lateral Epicondyle
Adjacent Intermuscular Septum
Inserts with Extensor Digitorum
Insertion of Extensor Digiti Minimi
Extensor hood of digit 5
Innervation of Extensor Digiti Minimi
Posterior Interosseous Nerve
continuation of deep branch of radial nerve
Function of Extensor Carpi Ulnaris
Extension and adduction of the wrist
Origin of Extensor Carpi Ulnaris
Lateral Epicondyle
Ulna
Insertion of Extensor Carpi Ulnaris
Base of Metacarpal 5 (medial side)
Innervation of Extensor Carpi Ulnaris
Radial Nerve (branch to medial head of triceps)
Function of Anconeus
Abduction of ulna during pronation
Accessory flexor
Origin of Anconeus
Lateral Epicondyle
Insertion of Anconeus
Posterior Ulna and Olecranon
Innervation of Anconeus
Radial Nerve (branch to medial head of triceps)
Function of Supinator
Supination of the arm and hand
Origin of Supinator
Lateral Epicondyle and ligaments (superficial head)
Supinator crest of ulna (deep head)
Insertion of Supinator
Lateral surface of radius (superior to anterior oblique line)
Innervation of Supinator
Deep Branch of Radial Nerve (Posterior Interosseus Nerve
Function of Abductor Pollicis Longus
Abduction of Digit 1
at joint between metacarpal and trapezium
Origin of Abductor Pollicis Longus
Posterior Ulna and Radius
Interosseus Membrane
Insertion of Abductor Pollicis Longus
Lateral base of Metacarpal 1
Innervation of Abductor Pollicis Longus
Posterior Interosseous Nerve
continuation of deep branch of radial nerve
Function of Extensor Pollicis Brevis
Extension of Metacarpo-phalangeal and carpometacarpal joints of the Thumb
Origin of Extensor Pollicis Brevis
Posterior Radius distal to Abductor PB origin
Interosseus Membrane
Insertion of Extensor Pollicis Brevis
Dorsal base of Proximal Phalanx of Digit 1
Innervation of Extensor Pollicis Brevis
Posterior Interosseous Nerve
continuation of deep branch of radial nerve
Function of Extensor Pollicis Longus
Extension of all thumb joints
Origin of Extensor Pollicis Longus
Posterior Ulna
Adjacent Interosseus Membrane
Insertion of Extensor Pollicis Longus
Dorsal base of Distal Phalanx of Digit 1
Innervation of Extensor Pollicis Longus
Posterior Interosseous Nerve
continuation of deep branch of radial nerve
Function of Extensor Indicis
Accessory extensor of the index finger (Digit 2)
Origin of Extensor Indicis
Posterior Ulna
Adjacent Interosseus Membrane
Insertion of Extensor Indicis
Extensor hood of Digit 2
Innervation of Extensor Indicis
Posterior Interosseous Nerve
continuation of deep branch of radial nerve