Forearm and Wrist Flashcards
Anconeus
Origin:
1. lateral epicondyle of the humerus
Insertion:
1. olecranon process
2. posterior proximal ulna
Action:
1. abducts ulna during pronation (allows for pronation)
2. assists with elbow extension
innervation
1. radial nerve C6-C8
Brachioradialis
Origin:
1. lateral supracondylar ridge of the humerus
Insertion:
1. lateral/distal side of the radius
Action:
1. flexes the elbow, when forearm is in mid-pronation
Innervation:
1. Radial nerve C5,C6
Extensor Carpi Radialis longus
origin:
1. lateral supracondylar ridge of humerus
Insertion:
1. base of 2nd metacarpal
Action:
1. extends wrist
2. radial deviation (abducts the wrist)
Innervation:
1. radial C6,C7
Extensor Carpi Radialis Brevis
Origin:
1. lateral epicondyle of humerus
Insertion:
1. base of 3rd metacarpal
Action:
1. extends wrist
2. abducts wrist (radial deviation)
Innervation: radial (deep branch C7,C8)
Extensor Digitorum
Origin:
1. lateral epicondyle of humerus
Insertion:
1. bases of middle and distal phalanges of finger 2-5 via extensor hoods
Action:
1. extends fingers 2-5
Inneravtion:
1. Posterior interosseous C7,C8
Extesnor Digiti Minimi
Origin:
1. lateral epicondyle of the humerus
Insertion:
1. extensor expansion of finger 5
Action:
1. extends finger 5
Innervation
1. posterior interosseous C7,C8
Extensor Carpi Ulnaris
origin
1. lateral epicondyle of humerus/common extensor tendon
Insertion:
1. base of 5th metacarpal
Action:
1. extends wrist
2. adducts wrist
Innervation:
1. posterior interosseous C7,C8
Supinator
Origin:
1. superficial head: lateral epicondyle of humerus/anular ligament
2. deep head: supinator crest (posterolateral ulna)
Insertion:
1. proximal radius
Action
1. supinates forearm
Innervation
1. radial (deep branch)
C6,C7
Abductor Pollicis Longus
origin:
1. posterior radius
2. mid-portion of posterolateral ulna
Insertion
1. base of metacarpal 1
actions:
1. abducts the thumb at carpometacarpal joint (CMC)
2. helps with thumb extension
Innervation:
1 posterior interosseous nerve C7,C8
Extensor Indicis
Origin:
1. posterior ulna
Insertion
1. extensor hood of index finger
Action
1. exntends 2nd finger
Innervation
1. psterior interosseous C7,C8
Extensor Pollicis Brevis
Origin:
1. posterior radius
Insertion:
1. base of the proximal phalanx of the thumb
Action:
1. extends the thumb metacarpophalangeal joint
2. assists with 1st CMC extension
innervation:
1. posterior interosseous nerve C7,C8
Extensor Pollicis Longus
Origin:
1. Posterior ulna
Insertion:
1. base of the distal phalanx of the thumb
Action:
1. extends the thumb at the interphalangeal joint (IP)
2. assists with extension of CMC and MCP
innervation:
1. posterior interosseous nerve C7,C8
Pronator Teres
Origin:
1. Humeral head: medial epicondyle of humerus, medial supracondrylar ridge
2. ulnar head: medial side coronoid process of ulna
Insertion:
1. lateral side shaft of the radius
Action:
1. pronates the forearm
innervation: median nerve C6,C7
Flexor Carpi Radialis
Origin:
1. medial epicondyle of the humerus
Insertion:
1. base of the second and third metacarpals
Action:
1. flexes the wrist,
2. abducts the hand (radial deviation)
innervation:
1. median nerve C6,C7
Palmaris Longus
Origin:
1. medial epicondyle of the humerus
Insertion:
1. palmar aponeurosis (thick layer of deep fasic to keep skin on palm)
Action:
1. flexes the wrist (weak)
innervation:
1. median nerve C7,C8
Flexor Carpi Ulnaris
Origin:
1. humeral head: medial epicondyle of humerus
2. ulanr head: olecranon process and posterior border of ulna
Insertion:
1. pisiform
2. hamate
3. base of 5th metacarpal
Action:
1. flexes wrist,
2. adducts hand
innervation:
1. ulnar nerve C7,C8,T1
Flexor Digitorum Superficialis
Origin:
1. humero-ulnar head: medial epicondyle of humerus and coronoid process of ulna
2. radial head: oblique line of radius
Insertion:
1. four tendons that bifurcate to attach to palmar surfaces of middle phalanges of medial four fingers
Action:
1. flexes the PIP joints of fingers 2-5
innervation: median Nerve C8-T1
Flexor Digitorum Profundus
Origin:
1. anterior/medial ulna
2. interosseous membrane
Insertion:
1. 4 tendons attach to palmar surface of distal phalanges of fingers 2-5 (pass through the split)
Action:
1. flexes the DIP joint of finger 2-5
innervation:
1. median nerve (radial one-half);
2. ulnar nerve (ulnar one-half)
C8,T1
Flexor Pollicis Longus
Origin:
1. anterior surface of radius
2. interosseous membrane
Insertion:
1. base of the distal phalanx of the thumb (palmar side)
Action:
1. flexes the interphalangeal joints of the thumb
innervation:
1. median nerve C7,C8
Pronator Quadratus
Origin:
1. distal anterior surface the ulna
Insertion:
1. distal anterior surface of the radius
Action:
1. pronates the forearm
innervation:
1. median nerve C7,C8
Anatomical Snuff Box
Boarders:
- abductor pollicis longus
- extensor pollicis brevis
- Extensor pollicis longus
Contents:
1. Radial artery
2. scaphoid
Radial nerve supplies (in forearm)
Sensory:
- back of arm
- posterior forearm
- posterior hand
Motor:
- brachioradialis
- anconeus
- ECRL
- ECRB
- supinator
Radial Nerve Course in the forearm
- enters by the lateral epiondyle
- bifurcates into superficial and deep
- superficial becomes sensory
- deep pierces the supinaotr heads and becomes posterior interosseous
Radial Nerve entrapements
Between supinator heads:
- lose thumb intriniscs and ECU
- no wrist drop but may have RD
- no sensory deficits
Radial tunnel (between brachioradilias and brachilis)
- also if lateral epicondyle is fx
- spared: only supinator and brachioradialis
- wrist drop will occur since motor loss will occur below ECRL
- sensory below entrapment
may need a brace to reduce active insufficiency
