Week 12 - Muscles of the Forearm and Hand Flashcards
What are the muscles of the superficial layer of the anterior compartment of the forearm?
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor carpi ulnaris
What are the actions of the pronator teres?
- Flexes forearm
- Pronates forearm
- Rotates the radius across the anterior surface of the ulna to pronate the forearm
What is the innervation of the pronator teres?
Median nerve (C6-C7)
What is the origin of the pronator teres?
Medial epicondyle of humerus
What is the insertion of the pronator teres?
Midshaft of radius
What are the actions of the flexor carpi radialis?
- Flexes forearm
- Flexes wrist
- Wrist and hand abduction
What is the innervation of the flexor carpi radialis?
Median nerve
What is the origin of the flexor carpi radialis?
Medial epicondyle of the humerus
What is the insertion of the flexor carpi radialis?
- Base of 2nd and 3rd metacarpals
What are the actions of the palmaris longus?
- Flexes forearm
- Weak wrist flexion
What is the innervation of the palmaris longus?
Median nerve (C6-C7)
What is the origin of the palmaris longus?
Medial epicondyle of humerus
What is the insertion of the palmaris longus?
Palmar aponeurosis (triangular-shaped sheet of fibrous tissue located in the palm of the hand)
What are the actions of the flexor carpi ulnaris?
- Flexes the forearm
- Flexes the wrist/hand
- Adducts the wrist/hand
What is the innervation of the flexor carpi ulnaris?
Ulnar nerve (C8-T1)
What is the origin of the flexor carpi ulnaris?
Medial epicondyle of the humerus
What is the insertion of the flexor carpi ulnaris?
- Base of the 5th metacarpal
What muscle is in the intermediate layer of the anterior compartment of the forearm?
- Flexor digitorum superficialis
What are the actions of the flexor digitorum superficialis?
- Flexes middle interphalangeal joints
- Flexes forearm
- Flexes wrist
What is the innervation of the flexor digitorum superficialis?
Median nerve (C6-C7)
What is the origin point of the flexor digitorum superficialis?
- Medial epicondyle of humerus
- Coronoid process of ulna
What is the insertion of the flexor digitorum superficialis?
- Middle phalanges of digits 2-5
What muscles form the deep layer of the anterior compartment of the forearm?
- Flexor pollicis longus
- Flexor digitorum profundus
- Pronator quadratus
What are the actions of the flexor pollicis longus?
- Flexes distal phalanx of thumb
- Weakly flex wrist
What is the innervation of the flexor pollicis longus?
Median nerve (C6-C7)
What is the origin point of the flexor pollicis longus?
Anterior shaft of radius
What is the insertion of the flexor pollicis longus?
Distal phalanx of digit 1
What are the actions of the flexor digitorum profundus?
- Flexes distal interphalangeal joints
- Flexes wrist
What is the innervation of the flexor digitorum profundus?
Lateral half –> 1/2 median nerve (C6-C8)
Median half –> 1/2 ulnar nerve (C8)
What is the origin of the flexor digitorum profundus?
- Medial/anterior ulna
- Interosseous membrane
What is the insertion of the flexor digitorum profundus?
Distal phalanges of digits 2-5
What is the action of the pronator quadtatus?
- Pronates forearm
What is the innervation of the pronator quadratus?
Median nerve (C8-T1)
What is the origin of the pronator quadratus?
Distal 1/4 of ulna
What is the insertion of the pronator quatratus?
Distal 1/4 of radius
What are the 7 muscles that form the superficial layer of the posterior compartment of the forearm
- Brachioradialis
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Extensor digitorum
- Extensor digiti minimi
- Extensor carpi ulnaris
- Anconeus
What are the actions of the brachioradialis?
- Flexes forearm
What is the origin point for the brachioradialis?
- Lateral supracondylar ridge of humerus
What is the insertion point of the brachioradialis
Radial styloid process
What is the innervation of the brachioradialis?
Radial nerve
What are the actions of the extensor carpi radialis longus?
- Extends wrist
- Abducts wrist/hand
What is the innervation of the extensor carpi radialis longus?
Radial nerve
What is the origin of the extensor carpi radialis longus
- Lateral supracondylar ridge of the humerus
What is the insertion of the extensor carpi radialis longus?
Base of 2nd metacarpal
What are the actions of the extensor carpi radialis brevis
- Extends wrist
- Abducts wrist
What is the innervation of the extensor carpi radialis bevis?
Radial nerve
What is the origin of the extensor carpi radialis brevis?
Lateral epicondyle of humerus
What is the insertion of the extensor carpi radialis brevis?
Base of 3rd metacarpal
What are the actions of the extensor digitorum?
- Extends digits 2-5
- Extends wrist
What is the innervation of the extensor digitorum
Radial nerve
What is the origin of the extensor digitorum?
Lateral epicondyle of humerus
What is the insertion of the extensor digitorum?
Middle and distal phalanges of fingers 2-5
What is the action of the extensor digiti minimi?
- Extends little finger (finger 5)
What is the innervation of the extensor digiti minimi?
The radial nerve
What is the origin of the extensor digiti minimi?
The lateral epicondyle of the humerus
What is the insertion of the extensor digiti minimi?
- Proximal and distal phalanx of finger 5
What are the actions of the extensor carpi ulnaris?
- Extends wrist
- Adducts wrist/hand
What is the innervation of the extensor carpi ulnaris?
Radial nerve
What is the origin of the extensor carpi ulnaris?
Lateral epicondyle of humerus
What is the insertion of the extensor carpi ulnaris?
Base of 5th metacarpal
What are the actions of the anconeus
- Extends the forearm weakly
What is the innervation of the anconeus?
Radial nerve
What is the origin of the anconeus?
Lateral epicondyle of humerus
What is the insertion of the anconeus
Olecrannon process of the ulna
What are the muscles of the deep layer of the posterior compartment of the forearm (arranged lateral to medial)
- Supinator
- Abductor pollicis longus
- Extensor pollicis brevis
- Extensor pollicis longus
- Extensor indicis
What is the action of the supinator?
Supinates forearm
What is the innervation of the supinator?
Radial nerve
What is the origin of the supinator?
- Lateral epicondyle of humerus
- Ulna (area distal to radial notch)
What is the insertion of the supinator?
Anterolateral surface of radius
What are the actions of the abductor pollicis longus?
- Abducts thumb
- Extends thumb and weakly wrist
What is the innervation of the abductor pollicis longus?
Radial nerve
What is the origin of the abductor pollicis longus?
- Proximal dorsal surfaces of radius and ulna
- Interosseous membrane
What is the insertion of the abductor pollicis longus?
- Lateral edge of metacarpal 1 (thumb)
What are the actions of the extensor pollicis brevis?
- Extends thumb and weakly wrist
What is the innervation of the extensor pollicis brevis?
Radial nerve
What is the origin of the extensor pollicis brevis?
- Posterior surface of the radius
- Interosseous membrane
What is the insertion of the extensor pollicis brevis?
Proximal phalanx of the thumb
What are the actions of the extensor pollicis longus?
- Extends thumb and weakly wrist
What is the innervation of the extensor pollicis longus?
Radial nerve
What is the origin of the extensor pollicis longus?
- Posterior surface of ulna
- Interosseous membrane
What is the insertion of the extensor pollicis longus?
- Distal phalanx of thumb
What are the actions of the extensor indicis?
- Extends index finger (pointer finger)
What is the innervation of the extensor indicis
Radial nerve
What is the origin of the extensor indicis?
- Posterior surface of the ulna
- Interossous membrane
What is the insertion of the extensor indicis?
- Tendon of the extensor digitorum
- Middle and distal parts of 2nd phalanx
What are the muscles of the hand? (two groups and one other muscle)
- Thenar eminence (muscles in ball of thumb)
- Hypothenar eminence (muscles in ball of little finger)
- Adductor pollicis
What are the muscles of the hypothenar eminence group?
- Flexor digiti minimi brevis
- Abductor digiti minimi
- Opponens digiti minimi (deep to the other two)
What are the muscles of the thenar eminence group?
- Flexor pollicis brevis
- Abductor pollicis brevis
- Opponens pollicis (deep to the other two)
What is the action of the flexor digiti minimi brevis?
Flexes finger 5 (pinky)
What is the origin of the flexor digiti minimi brevis?
- Hamate bone (carpal bone)
- Flexor retinaculum
What is the insertion of the flexor digiti minimi?
Proximal phalanx of finger 5
What is the innervation of the flexor digiti minimi brevis?
Ulnar nerve
What is the action of the abductor digiti minimi?
Abducts finger 5
What is the origin of the abductor digiti minimi?
- Pisform bone
- Tendon of flexor carpi ulnaris
What is the insertion of the abductor digiti minimi?
- Proximal phalanx of finger 5
What is the innervation of the abductor digiti minimi?
Ulnar nerve
What is the action of the opponens digiti minimi?
Opposition of finger 5
What is the origin of the opponens digiti minimi
- Hamate bone
- Flexor retinaculum
What is the insertion of the opponens digiti minimi?
Metacarpal bone 5
What is the innervation of the opponens digiti minimi?
Ulnar nerve
What is the action of the flexor pollicis brevis?
Flexes thumb
What is the origin of the flexor pollicis brevis?
- Flexor retinaculum
- Trapezium
What is the insertion of the flexor pollicis brevis?
Proximal phalanx of thumb
What is the innervation of the flexor pollicis brevis?
Median nerve
What is the action of the abductor pollicis brevis?
Abducts thumb
What is the origin of the abductor pollicis brevis?
- Flexor retinaculum
- Scaphoid
- Trapezium
What is the insertion of the abductor pollicis brevis?
Lateral side of proximal phalanx of thumb
What is the innervation of the abductor pollicis brevis?
Median nerve
What is the action of the opponens pollicis brevis?
Opposition of thumb
What is the origin of the opponens pollicis?
- Flexor retinaculum
- Trapezium
What is the insertion of the opponens pollicis?
- Lateral side of metacarpal 1
What is the innervation of the opponens pollicis?
Median nerve
What is the action of the adductor pollicis?
Adducts thumb
What is the origin of the adductor pollicis?
Metacarpal 3
What is the insertion of the adductor pollicis?
Medial side of proximal phalanx of thumb
What is the innervation of the adductor pollicis?
Ulnar nerve