Myology of the Wrist and Hand Flashcards
Flexor Carpi Radialis
O- Medial epicondyle via common flexor tendon
I- Palmer surface bases of 2nd and 3rd metacarpal
N- Median Nerve C6-C8
A- Flexion, synergist for radial deviation
Flexor Carpi Ulnaris
O- Medial epicondyle via common flexor tendon
I- Pisiform, hook of hammate, 5th metacarpal
N- Ulnar Nerve C7-8, T1
A- Flexion at wrist, ulnar deviation
Palmaris Longus
O- Medial epicondyle (flexor tendon)
I- Palmer aponeurosis/ Flexor retinaculum
N- Median Nerve C7-8,
A- Tense the palmer fascia, flex wrist (weak)
Palmer Aponeurosis
Triangular in shape.
Apex is continous with the Palmaris Longus tendon.
Fibers radiate to extensions at base of digits.
Key role in protection.
Flexor Digitorum Profundus
O- Anterior surface of ulna and interosseous membrane.
I- 4 tendons- distal 2-4 phalanges
N- 2-3 Median Nerve C7-8, T1
4-5 Ulnar Nerve C7-8, T1
A- Flexes 2-5 fingers at MCP + distal IP joints, assists to flex wrists
Contained within fibrous sheaf after exiting the carpal tunnel.
Flexor Digitorum Superficialis
O- Medial epicondyle, ulna collateral ligament, coranoid process of ulna and shaft of radius.
I- 4 tendons- middle 2-4 phalanges
N- Median Nerve C7-8, T1
A- Flexes proximal interphalangeal joint, flexes 2-5 MCP joints
Contained within fibrous sheaf after exiting the carpal tunnel.
Extensor Carpi Radialis Longus
O- Lower 1/3 supracondyler ridge
I- Base of 2nd metacarpal
N- Radial Nerve C6-8
A- Extends wrist, synergist for radial deviation
Extensor Carpi Radialis Brevis
O- Lateral epicondyle via common extensor tendon
I- Base of 3rd metacarpal
N- Radial Nerve C6-8
A- Extend wrist, synergist for radial deviation.
Extensor Carpi Ulnaris
O- Lateral epicondyle via common extensor tendon
I- Base of 5th metacarpal
N- Radial C6-8
A- Wrist extension, synergist for ulna deviation.
Extensor Digitorum
O- Lateral epicondyle via common extensor tendon
I- 4 tendons via extensor hoods to dorsal aspects of bases 2-4 middle and distal phalanges.
N- Radial Nerve C6-8
A- Extends fingers and wrist joints
Forms part of the anatomical snuffbox on radial side of wrist.
Extensor Indicis
O- Posterior surface of teh distal ulna, Interosseous membrane.
I- Extensor hood at level of 2nd metacarpal (index finger)
N- Posterior interosseous nerve/ Radial nerve C6-8
A- Extend index finger
Indicis- Index finger
Extensor Hood
Moveable triangular hood lying proximally over MCP joints.
Transfers force and allows fine precise movements.
BAse- wraps around sides of MCP joints and attatches to the deep transverse metacarpal ligaments.
Thenar and Hyperthenar Muscles
Thenar: Flexor Pollicis Brevis, Abductor Pollicis Brevis, opponens Pollicis.
Hytperthenar: Flexor digiti minim brevis, Abductor digiti minimi, Opponenes digit minini.
Hypothenar muscles produce the hyperthenar eminence, medial side of pal.
Flexor Pollicis Longus
O- Anterior surface of radius and interosseous membrane between radial tubersoity and pronanator quadratus.
I- Distal phalanx of thumb.
N- Median Nerve C7-8, T1
A- Only flexor to distal phalanx of thumb, assists wrist flexion.
Abductor Pollicis Longus
O- Posterior surfaces of distal half of radius and ulna, interosseous membrane.
I- Radial side base metacarpal thumb.
N- Radial Nerve C6-8
A- Abducts thumb, extends thumb.
Snuff box formation.
Extensor Pollicis Brevis
O- Middle third posterior surfaces of ulna, interosseous membrane.
I- Dorsal surface base distal phalanx thumb.
N- Radial Nerve C6-8
A- Abducts the thumb, extends MCP joints
Forms part of anatomical snuff box.
Extensor Pollicis Longus
O- Middle third posterior surfaces of ulna and interosseous membrane.
I- Dorsal surface base distal phalanx thumb.
N- Radial Nerve C6-8
A- Extends all joints in thumb, abducts the wrist
Forms part of snuff box.
Lumbircals of the hand
O- Surfaces of the flexor digitorum profundus tendons.
I- Extensor aponeurosis on dorsal surfaces of phalages.
N- 2-3: Median Nerve C6-8, T1. 4-5: Ulnar Nerve C7-8, T1.
A- Extend 2-5 fingers at interphalangeal joints, flex 2-5 at metacarpophalangeal joints.
Palmer Interossei
O- Bases of 1, 2, 4 and 5th metacarpals.
I- Bases of proximal phalanx and extensor aponeurosis.
N- Ulnar Nerve C8, T1.
A- Abducts 1, 2, 4, 5 towards 3rd finger. Assists to flex MCP joints. Asissts to extend IP joints.
Dorsal Interossei
O- Adjacent sides of all metacarpals
I- Base of proximal phalanx 2/3/4 and extensor hood.
N- Ulna nerve C8, T1
A- Abducts 2/3/4 at MCP joint, Assist to flex 2/3/4 at MCP and assist to extend all IP joints.
Carpal Tunnel
Lateral to medial: Flexor Pollicis Longus, Median Nerve, 4 Flexor Digitorum Profundus Tendons, Flexor Digitorum Superficialis overlying.
Carpal Tunnel Syndrome: Pressure on nerve in wrist causing pain and numbness in hands.
Anatomical Snuff Box
Lateral to medial: Abductor Pollicis Longus, Extensor Pollicis Brevis and Extensor Pollicis Longus.
All muscles share the same tenden and innervated by the radial nerve.
‘Snuff box’ as tobacco could be put there and inhaled.
