Forearm and Wrist 1 Flashcards
forearm compartments and innervation
• Compartments – Anterior – Posterior • Innervation – Median nerve (+ Ulnar n.) – Radial nerve
wrist
• Wrist region – Hand • Carpus • Wrist joint – Between forearm & hand
radius
bones of the hand
joints of the forearm and wrist
Proximalradioulnarjoint
Interosseousmembrane
Distalradioulnarjoint
Wristjoint
Intercarpaljoints
Carpometacarpal joints
Metacarpophalangealjoints
Interphalangealjoints
forearm joints classification
• Proximalradioulnarjoint – Synovial pivot
• Interosseousmembrane
– aka Middle radioulnar joint – Fibrous syndesmosis
– Amphiarthrosis
• Distalradioulnarjoint – Synovial pivot
wrist joint
• Wrist joint
– Aka Radiocarpal joint
– Classification
• Synovial condylar
– Components • Radius
- Articular disc overlying ulna • Scaphoid
- Lunate
- Triquetrum
joints of the hand
– Intercarpal joints: • Synovial
• Movement:limited
– 1st Carpometacarpal joint: • Synovialsaddle
– Carpometacarpal joints 2-5: • Synovialplane
• Movement:gliding
– Metacarpophalangeal joints: • Synovialcondylar
– Interphalangeal joints: • Synovialhinge
• Proximal&distal
muscles of the elbow
• Anterior compartment of the forearm
– 8 muscles
• Posterior compartment of the forearm
– 12 muscles
muscles of the anterior compartment of the forearm
• Anterior compartment of the forearm
– Superficial layer (4) – Intermediate layer (1) – Deep layer (3)
– Superficial layer (4)
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
pronator teres
- Pronator teres – Origin
» Humeral head – medial epicondyle & supracondylar ridge
» Ulnar head – medial coronoid process – Insertion
» Lateral midshaft of radius – Innervation
» Median nerve – Action
» Pronation
flexor carpi radialis
- Flexor carpi radialis – Origin
» Medial epicondyle of humerus – Insertion
» Base of MC 2 & 3 – Action
» Wrist flexion & abduction – Innervation
» Median nerve
palmaris longus
- Palmaris longus – Origin
» Medial epicondyle of humerus
– Insertion
» Palmar aponeurosis
– Action
» Wrist flexion
» Resist shearing forces when gripping
– Innervation
» Median nerve
flexor carpi ulnaris
4.
Flexor carpi ulnaris
• Origin
– Humeral head – medial epicondyle of humerus
– Ulnar head – olecranon & posterior border of ulna
• Insertion
– Pisiform
– Hamate & MC 5 base • Action
– Wrist flexion & adduction • Innervation
– Ulnar nerve
flexor digitorum superficialis
- Flexor digitorum superficialis – Origin
» Humero-ulnar head:
» medial epicondyle of humerus & ulnar coronoid process margin
» Radial head:
» Oblique line
– Insertion
» Palmar surface of middle phalanges of digits 2-5
– Action
» Flexion of PIP & MCP of digits 2-5 & wrist
– Innervation
» Median nerve
flexor digitorum profundus
- Flexor digitorum profundus – Origin
» Antero-medial ulna & interosseous membrane
– Insertion
» Palmar surface of distal phalanges of digits 2-5
– Action
» Flexion of DIP & MCP of digits 2-5 & wrist
– Innervation
» Lateral half by median nerve (ant interosseous nerve)
» Medial half by ulnar nerve
flexor pollicis longus
- Flexor pollicis longus – Origin
» Anterior radius & lateral interosseous membrane
– Insertion
» Palmar surface of base of distal phalanx of thumb
– Action
» Flexion of interphalangeal & metacarpophalangeal joints of thumb
– Innervation
» Median nerve (ant interosseous nerve)
pronator quadratus
- Pronator quadratus
– Origin
» Antero-distal ulna
– Insertion
» Antero-distal radius
– Action
» Pronation
– Innervation
» Median nerve (ant interosseous nerve)
blood supply
nerve supply
brachioradialis
- Brachioradialis – Origin
» Lateral supracondylar ridge of humerus & intermuscular septum
– Insertion
» Distolateral radius
– Innervation
» Radial nerve
– Action
» Elbow flexion synergist in midpronation
» Pronate supinated forearm
» Supinate pronated forearm
extensor carpi radialis longus
- Extensor carpi radialis longus – Origin
» Distal lateral supracondylar ridge of humerus & intermuscular septum
– Insertion
» Dorsal surface of MC2 base
– Innervation
» Radial nerve
– Action
» Wrist extension & abduction
extensor carpi radialis brevis
- Extensor carpi radialis brevis – Origin
» Lateral epicondyle of humerus & intermuscular septum
– Insertion
» Dorsal surface of MC2 & MC3 base
– Innervation
» Radial nerve (deep branch)
– Action
» Wrist extension & abduction
extensor digitorum
- Extensor digitorum – Origin
» Lateral epicondyle of humerus & intermuscular septum & deep fascia
– Insertion
» Dorsal base of middle & distal phalanges of digits 2-5 via extensor hoods
– Innervation
» Radial nerve (posterior interosseous n.)
– Action
» Extend digits 2-5 & wrist
extensor digiti minimi
- Extensor digiti minimi – Origin
» Together with extensor digitorum – Insertion
» Extensor hood of digit 5 – Innervation
» Radial nerve (posterior interosseous n.) – Action
» Extend digit 5
extensor carpi ulnaris
- Extensor carpi ulnaris – Origin
» Lateral epicondyle of humerus & ulna posterior border
– Insertion
» Tubercle on medial side of MC5 base
– Innervation
» Radial nerve (posterior interosseous n.)
– Action
» Wrist extension & adduction
anconeus
- Anconeus – Origin
» Lateral epicondyle of humerus & ulna posterior border
– Insertion
» Olecranon & postero-superior ulna
– Innervation
» Radial nerve
– Action
» Abduct ulna in pronation » Elbow extension synergist
supinator
- Supinator – Origin
» Superficial - Lateral epicondyle of humerus & radial collateral & annular ligaments
» Deep – supinator crest of ulna – Insertion
» Radius superolateral to oblique line – Innervation
» Radial nerve – Action
» Supination
abductor pollicis longus
- Abductor pollicis longus – Origin
» Posterior ulna, radius & interosseous membrane distal to anconeus & supinator
– Insertion
» Lateral MC1 base
– Innervation
» Radial nerve (posterior interosseous n.)
– Action
» Abduct carpometacarpal joint of thumb
» Thumb extension synergist
extensor pollicis brevis
- Extensor pollicis brevis – Origin
» Posterior radius & interosseous membrane distal to abductor pollicis longus
– Insertion
» Dorsal base of thumb proximal phalanx
– Innervation
» Radial nerve (posterior interosseous n.)
– Action
» Extend carpometacarpal & metacarpophalangea joints of thumb
extensor pollicis longus
- Extensor pollicis longus – Origin
» Posterior ulna & interosseous membrane distal to abductor pollicis longus
– Insertion
» Dorsal base of thumb distal phalanx
– Innervation
» Radial nerve (posterior interosseous n.)
– Action
» Extend digit 1
extensor indicis
- Extensor indicis – Origin
» Posterior ulna & interosseous membrane distal to extensor pollicis longus
– Insertion
» Digit 2 extensor hood
– Innervation
» Radial nerve (posterior interosseous n.)
– Action
» Extend digit 2
neurovasculature of the posterior forearm
carpal arch
• Sides
– Lateral
• Scaphoid&trapezium tubercles
– Medial
• Hamate hook & pisiform
– Roof
• Restofcarpals
carpal tunnel
• Contents
– flexordigitorum profundus
– flexordigitorum superficialis
– flexorpollicislongus – median nerve
forearm fractures
– Monteggia’s fracture- dislocation
- fractureP1/3ulna
- dislocationofheadofradius
– Galeazzi’s fracture-dislocation • fractureofD1/3radius
• dislocationofheadofulna
– Colles’ fracture
• Distalradiusfractureand posterior displacement
– Parry
• Distalulnafracture
