03-08: The Hand Flashcards
Joints of the Thumb (3)
Carpometacarpal (CMC or CM) joint - Trapezium articulates with base of 1st metacarpal
Metacarpophalangeal (MCP or MP) joint - 1st metacarpal articulates with proximal phalanx
Interphalangeal (IP) joint - Articulation between proximal and distal phalanx
Thumb Motion - Flexion/Extension
Frontal plane about a sagittal axis (Cave on vex)
Flexion - 40˚, combines with slight rotation, medial glide
Extension - Lateral glide
Thumb Motion - Abduction/Adduction
Sagittal plane about a frontal axis (Vex on cave)
Abduction - Posterior roll, anterior glide
Adduction - Anterior roll, posterior glide
Thumb Motion - Opposition/Reposition
- Opposition is THREE movements - Abduction, flexion, rotation (rotary component)
- Opposition/Reposition separates us from primates (opposable thumbs)
Apehand Deformity
Condition in which there is an Inability to oppose thumb
Joints of fingers (Digits 2-5)
Carpometacarpal - Carpals and metacarpals
Metacarpophalangeal - “knuckles”
Proximal interphalangeal - PIP
Distal interphalangeal - DIP
CMC Joint of the Thumb
Gives mobility and stability
CMC Joint of the Fingers
Provides more stability than mobility
2nd-3rd digits: stationary
4th-5th digits: more mobile
5th digit has most CMC mobility (fist)
Boxer’s Fracture
Fx of the neck of distal 5th metacarpal
Range of Motion (MCP, PIP, DIP)
MCP: Flexion, extension, abduction, adduction, hyperextension
PIP: Flexion, extension
DIP: Flexion, extension
Arthrokinematics of hand joints
Radiocarpal - Vex on Cave (opposite glide/roll)
Intercarpal - Non-axial
CMC - Non-axial gliding (2-5), Saddle (1st digit)
1st CMC - Saddle - Sagittal (Vex on Cave), Frontal (Cave on Vex)
MCP - Cave on vex (Biaxial)
IP - Cave on Vex (Uniaxial)
Flexor Retinaculum Ligament
- Prevents bowstringing
- Fibrous band on anterior surface
- Transverse carpal, palmar carpal ligament
- Structures (10) run underneath and distal to FR
Extensor Retinaculum Ligament
Fibrous band on posterior surface
Extensor Expansion Ligament
- Extensor hood, attaches to distal phalanx
- Provides attachment for several muscles
Tunnel of Guyon
Canopy formed by pisohamate ligament; ulnar nerve runs underneath
Anterior extrinsic muscles
Flexor digitorum superficialis
Flexor digitorum profundus
Flexor pollicis longus
Posterior extrinsic muscles
Extensor digitorum communis
Extensor digitorum indicis
Extensor digiti minimi
Lateral extrinsic muscles
Abductor pollicis longis
Extensor pollicis brevis
Extensor pollicis longus
Flexor Digitorum Superficialis
O: Medial epicondyle of humerus, coracoid process of ulna, Middle of anterior radius
I: Lateral aspects of middle phalanges 2-5
A: Flexes PIP, MCP, radiocarpal joint
N: Median nerve
- Origin forms canopy for median nerve to pass underneath - can be area of impingement
- Most superficial finger flexors - deep to wrist flexors
- Bifurcates at middle phalange
Flexor Digitorum Profundus
O: Anterior aspect of proximal ulna, interosseous membrane
I: Volar aspect of the base of distal phalanges 2-5 (runs deep to FDS)
A: Flexes DIP, PIP, MCP, radiocarpal joints
N: Median nerve (Digits 2-3), Ulnar nerve (Digits 4-5)
Flexor Pollicus Longus
O: Anterior aspect of radius, interosseous membrane
I: Volar aspect of distal phalange 1 (1st digit)
A: Flexes IP, MCP, assists with radial radiocarpal joint flexion
N: Median nerve
Extensor Digitorum Communis
O: Common extensor tendon
I: Extension hood (Dorsum of distal phalange) Digits 2-4
A: Extends DIP, PIP, MCP, radiocarpal joint
N: Radial nerve
Extensor Digitorum Indicis
O: Posterior aspect of ulna
I: Extensor hood of 2nd digit
A: Extends DIP, PIP, MCP, Radiocarpal joint of digit 2
N: Radial nerve
Extensor Digiti Minimi
O: Common extensor tendon
I: Extensor hood of 5th digit
A: Extends DIP, PIP, MCP, Radiocarpal joint of digit 5
N: Radial nerve
Abductor Pollicis Longus
O: Posterior aspect of ulna, interosseous membrane, posterior radius
I: Base of 1st metacarpal
A: Abduction of 1st digit
N: Radial nerve
Extensor Pollicis Brevis
O: Posterior aspect of radius, interosseous membrane
I: Base of proximal phalange of 1st digit
A: Extends MCP, radiocarpal joint
N: Radial nerve
Extensor Pollicis Longus
O: Posterior ulna, interosseous membrane
I: Base of distal phalange of 1st digit
A: Extends DIP, MCP, radiocarpal joint; assists with supination
N: Radial nerve
Anatomical Snuffbox
- Depression on the lateral side of the hand/thumb
- Made up of APL, EPB, EPL
- Base is the scaphoid
“Sign of the Pope”
- Median nerve injury
- Making fist: Can’t bend 1st three digits, wrist
- Not deformity, just sign when making fist
- No opposing to bring thumb forward
“Jersey finger”
Avusion injury - tendon ripped from bone in DIP, cannot activate phalange
Thenar Muscles
- Flexor pollicis brevis
- Abductor pollicis brevis
- Opponens pollicis (Deepest muscles)
- Ennervated by median nerve
Hypothenar Muscles
- Flexor digiti minimi
- Abductor digiti minimi
- Opponens digiti minimi (Deepest muscles)
- Ennervated by ulnar nerve
Deep Palmar Muscles
- Lumbricals
- Palmar interossei (Lies between metacarpals)
- Dorsal interossei (Lies between metacarpals)
- Adductor pollicis
Flexor Pollicis Brevis
A: Flexes 1st digit
N: Median nerve
- Thenar
Abductor Pollicis Brevis
A: Abducts 1st digit
N: Median nerve
- Thenar
Opponens Pollicis
A: Opposes 1st digit
N: Median nerve
- Thenar
Flexor Digiti Minimi
A: Flexes 5th digit
N: Ulnar nerve
- Hypothenar
Abductor Digiti Minimi
A: Abducts 5th digit
N: Ulnar nerve
- Hypothenar
Opponens Digiti Minimi
A: Opposes 5th digit
N: Ulnar nerve
- Hypothenar
Adductor Pollicis
A: Adduction of 1st digit
N: Ulnar nerve
- Deeper palmar
- Last muscle ennervated by ulnar nerve
Dorsal Interossei (DAB)
O: Adjacent to metacarpals
I: Base of lateral aspects of proximal phalanx 2-4
A: Abducts digits 2-4
N: Ulnar nerve
- Deeper palmar
Palmar Interossei (PAD)
O: Adjacent to respective metacarpals
I: Base of respective proximal phalanx
A: Adducts digits 2, 4, 5
N: Ulnar nerve
- Deeper palmar
Lumbricals
O: Tendons of Flexor Digitorum Profundus 2-5
I: Extension hood of digits 2-5
A: Flexes MCP, Extends IP
N: Median nerve (Digits 2-3), Ulnar nerve (Digits 4-5)
Extensor Tendons at Wrist
Comp 1 - Abductor Pollicis Longus, Extensor Pollicis Brevis
Comp 2 - Extensor Carpi Radialis Longus, Extensor Carpi Radialis Brevis
Comp 3 - Extensor Pollicis Longus
Comp 4 - Extensor Digiti Communis, Extensor Digitorum Indicis
Comp 5 - Extensor Digiti Minimi
Comp 6 - Extensor Carpi Ulnaris
Colles Fracture
- FOOSH (Fall on an outstretched hand)
- Posterior displacement of distal radius (Fx)
Smith’s Fracture
Anterior displacement of distal radius (Fx)
Ganglion Cyst
- Benign tumor mass filled with clear, jelly-like fluid
- Located on either dorsal or volar aspect of hand
De Quervain’s Disease
- Inflammation of the sheath containing the EPB and APL
- Test using Finklestein’s Test, treat as tendinosis
Dupuytren’s Contracture
- Deformity
- Thickening in the palmar aponeurosis = fixed position that cannot be fixed with PT on its own
- Can be treated post-surgery (excise fibrous tissue)
Trigger Finger
- Tendon unable to slide in sheath due to swelling of either tendon or sheath
- Tendon passes during flexion, but locks in position (manual reposition)
Swan Neck Deformity
- Hyperextension of PIP and flexion of DIP
- Late stage results in ulnar drift
Boutonniere’s Deformity
Flexion of the PIP and extension of the DIP
Claw Hand
- Ulnar nerve
- Hyperextension of MCP
- Passive insufficiency of flexor tendons
Grind Test
- 1st metacarpal approximation
Finklestein’s Test
- De Quervain’s Syndrome
- Thumb in fist, test ulnar deviation
Phalen’s Test
- Carpal Tunnel Syndrome
- Hold dorsal surface of hands together to see if it affects fingers
Tinel’s Test
- Nerve irritation
- Tap, test to see if it sends signals of nerve irritation
Froment’s Sign
- Ulnar nerve test
- Adductor Pollicus
- Hold paper between 1st-2nd digit and test strength
Power Grip
Cylindrical grasp - fingers ADD, flex at MCP (bottle)
Spherical grasp - ABD and flexed fingers (doorknob)
Hook grasp - ABD and flexes at IPs (suitcase)
Prehension Grip
Pad to pad - finger pad to finder pad (pinch salt)
Pad to side - Pad of thumb to side of finger (keys)
Side to side - side of finger to side of finger (cigarette)
Lumbrical - Flexed MCP, extension of IP (water cup)
3-Jaw Chuck - 1st three digits come together (pulling a pickle out of jaw