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
Posterior interosseous nerve
- APL
- EPB
- EPL
- Extesnor indicis
- extensor digiti minimi
- extesnor ulnaris
- extesnor digitorum
Median nerve Supplies
- Pronator teres
- FCR
- palmaris longus
- FDS
- 1/2 FDP
- flexor pollicis longus
- pronator quadratus
- sensory to the lateral hand (thumb to 1/2 ring)
Median nerve entrapment
Carpal tunnel
- lose thenar and 1st two lumbricals
- sensory lose in the tips of thumb, index, middle and 1/2 ring
- snesory is spared in palm
Tests: phalens and reverse phalens
Ape hand deformity with median nerve issues
Ulnar nerve supplies
- FCU
- medial 1/2 FDP
Course of ulnar nerve
- comes into forearm from cubital tunnel
- pierces through FCU heads
- travels down the medial side of anterior compartment
Ulnar nerve entrapment
- between heads of FCU
- motor loss: all motor innervation in forearm and hand
- sensory: 1/2 ring adn pinky side of hand
- special tests: froment’s sig, ADM, wartenberg
Vascular structures in the forearm and wrist
- brachial artery from the arm splits into the raidl and ulnar artery
- ulnar artery: anterior ulnar recurrent artery, common interosseous artery and anterior interosseous artery
- radial artery: posterior interosseous artery, radial recurrent artery
Ulnar side of forearm: median cubtial veins, medial antecubtial vein, basilic vein
Radial side of forearm:
- cephalic vein, superficial veins of forearm
Dinner fork deformity
- recults from a colles fracture of distal radius
- malaligned healing
- distal fragment dorsally displaced
- commonly from FOOSH injry with wrist in extension
Symptoms of Dinner fork deformity/colles fx
- pain/tenderness with palpation
- edema
- bruising
- decrease ROM
Dx of dinner fork deformity
- imaging will indicate severity
- visual inspection
Special conisderation with
Dinner fork deformity
- may be externally fixed = risk of infection
- populations that may be more susceptible = eldery (osteoporosis), athletes
- healing time 6-8 weeks or longer
- primary bony healing (ORIF)
Dinner fork deformity
treatment
- surgery/casting
- mobility of other joints
- mobs - pain relief initially and then for motion
- stretching: AROM/PROM
- strengthening
Scaphoid fracture
- the potential result of FOOSH with radial deviation adn wrist extension
Scaphoid fracture
factors impacting prognosis
- location of the fx on scaphoid
- blood supply = has it been disrupted
- other medical conditions/nutrition/lifestyle
Scaphoid fracture
further complications
- malunion/nonunion
- OA
- acute compartment syndrome
Carpal tunnel syndrome
capral tunnel syndrome occurs when there is a compression of the median nerve uder the flexor sheath of the flexor retinaculum
Carpal tunnel syndrome
Symptoms
- numbness and tingling in median distrubtion of hand besides palm
- muscle weakness of the thenars and 1st two lumbicals
Carpal tunnel
Diagnosis and treatment
- NCS/EMG
Surgery:
- endoscopic or open
Nonsurgical:
- wrist splinting
- NSAIDs
- corticosteriod
- adjusting desk set up
Referred symptoms in the forearm
- Heart: MI symptoms can be felt here
- CRPS: injury in one area goes on to effect an entire limb
- radicular symptoms
Soft tissue sarcoma
symptoms
- symptoms can include
- nocticable lump or swelling
- can also be painful if it grows as it can apply pressure on muscles and nerves
Ganglion cyst
- also called bible cyst
- can cause pain if it is compressiong enough structures or the wrist undergoes repetitive movement
- most common = dorsum of wrist
