How many of each type of bone is there in the hand
27 Bones
8 Carpal 5 Metacarpal 5 proximal Phalanges 4 Middle Phalanges 5 Distal Phalanges
List the carpal bone
Scaphoid
Lunate
Triquetrum
Pisiform
Trapezium
Trapezoid
Capitate
Hamate
She Looks Too Pretty, Try To Catch Her
5 Main Joints of the wrist
Large CMC Joint Small CMC Joint Midcarpal Joints Radiocarpal Joint Distal Radioulnar Joint
[Ulnocarpal Joint]
TFCC
Triangular
Fibrocartilage Complex
Triangular in shape and made up of several ligaments and cartilage
Allows flexibility of wrist
Extrinsic Anterior Hand Muscles
Flexor Digiti Superficialis
Flexor Digiti Profundus
Intrinsic Medial Anterior Hand Muscles
Abductor Digiti
Flexor Digiti Minimi Brevis
Opponens Digiti Minimi
Intrinsic Lateral Anterior Hand Muscles
Superficial: Abductor Pollicis Brevis, Flexor Pollicis Brevis
Deep: Opponens Pollicis
Small subcutaneous anterior hand muscle
Palmaris Brevis
Intrinsic Adductor Compartment of Anterior Hand Muscles
Adductor Pollicis (Oblique Head at 2, 3 metacarpals & transverse head at ant. shaft of 3 metacarpal)
Attaches to medial side of proximal phalange of thumb
Lumbricals
Intrinsic Hand Muscles that flex metacarpophalangeal joints and extend interphalangeal joints
Arises from tendons of FDP to lateral side of distal end of proximal phalanges
Not on Thumb
Palmar Interosseus Muscles
Adduct the fingers and assist in flexion of metacarpohalangeal joints/extension of interphalangeal joints
Between metacarpals 2-5
Arising from 2, 3, 5 to bases proximal phalanges & extensor expansions of 2, 4, 5
Which muscles compose the central compartment of the hand muscles
Lumbricals
Palmar Interossei
Extrinsic Extensors of the Posterior Hand
Extensor Digitorum
Extensor Indicis
Extensor Digiti Minimi
What restricts independent extension of fingers
Linking of adjacent tendons by 3 oblique intertendinous connections
Thenar Extensors of the Posterior Hand
Abductor Pollicis Longus
Extensor Pollicis Longus & Brevis
Outcrop muscles that make anatomical snuff box
What does compresion of the median nerve in the carpal tunnel cause
Carpal Tunnel Syndrome
Volar Hand
Palmar Side
Is the median nerve volar or dorsal
Volar
Which Carpal Bones define the boundaries of the carpal tunnel
Laterally: Scaphoid & Trapezium tubercles
Medially: Pisiform and Hook of Hamate
Role of flexor retinaculum in creating the carpal tunnel
Turns the carpal arch into the carpal tunnel by bridging the space between the medial & lateral parts of the arch
It is a thick connective tissue which forms the roof of the carpal tunnel
What nerve is in the carpal tunnel
Median Nerve
Which tendons are in the carpal tunnel
Flexor Pollicis Longus
Flexor Digitorum Superficialis
Flexor Digitorum Profundus
Function of the Retinacula
Fixing the tendons to the wrist
Preventing bow-stringing & sideways sliding
Describe the finger pulley system
FDS & FDP are closesly fixed t ophalanges by a fibro-osseus tunnel formed by fibrous arches
- Provides biomechanical stability and prevents bowstringing
Describe the spread of the FDS & FDP tendons towards the distal phalanges
the FDS tendons split into 2 slips which divide around the FDP tendon and insert into the middle phalanx
- Allows FDP tendon to continue to distal phalanx
Muscles involved in Extension of Fingers
Extensor digitorum
Extensor indicis (Index finger)
Extensor digiti minimi (pinkie)
Muscles involved in extension of thumb
Extensor Pollicis Longus
Extensor Pollicis Brevis
Abductor Pollicis Longus
What is a highly sensitive test for scaphoid fracture
Anatomical Snuffbox Tenderness
What carpal bones does the radial artery lie on in the anatomical snuff box
Trapezium & Scaphoid
Which direction is thumb abduction
Perpendicular/Away from hand anteriorly
What movements make up thumb opposition
Simultaneous flexion & adduction
Dorsal Interossei
Dorsal Abduction
Movement as shown in diagram
Origin:
Adjacent sides of Metacarpals 2-5
Insertion:
1 & 2 - Base of proximal phalanges/extensor expansions 2, 3
2 & 3 - Base of proximal phalanges/extensor expansions 3, 4
2 Main types of grips
Power Grips
Precision Grips
3 Types of Power Grips
Cylindrical Grip
Spherical Grip
Hook Grip
3 Types of Precision Grips
Tripod Grasp (Pencil)
Plate Grip
Pinch Grip
1 Finger, Thum
Dorsiflexion & Muscles Involved
ECRL
ECRB
ECU
(green)
Palmarflexion & Muscles Involved
FCR
FCU
Palmaris Longus
(+ extrinsic finger flexors)
Dart-thrower’s motion
Combiner palmarflexion & ulnar deviation
Radial Deviation & Muscles Involved
All radial wrist muscles ECRL ECRB FCR (+ extrinsic thumb muscles)
(red)
Ulnar Deviation
All ulnar wrist muscles
ECU
FCU
(extensor digiti mini)
(blue)
Discuss distribution of ulnar & radial arteries in hand
What does the median nerve innervate in the hand
Sensory:
Lateral 3.5 digits
Palm of hand
Motor: Flexor muscles (Besdies FCU) and lateral 2 lumbricals
What does the ulnar nerve innervate in the hand
Sensory
Medial half of palm
Dorsal surface of medial 1.5 fingers and associates dorsal hand ares
Motor Majority of intrinsic hand muscles Hypothenar muscles (FDmB, ADM, ODM) Medial 2 lumbricals Adductor pollicis Palmar & Dorsal Interossei Palmaris brevis
What does the radial nerve innervate in the hand
Sensory
Lateral Aspect of dorsal hand
Dorsal surface of lateral proximo aspect 3.5 digits
Motor
Extensor Muscles
Most common carpal bone to dislocate
Lunate
Most common carpal bone to fracture
Scaphoid
Most commonly injured wrist ligament
Scapholunate Ligament
Most common overall fracture
Colle’s fracture
Why is a scaphoid fracture so serious
Has a high chance of causing avascular necrosis
Palsy
Various types of paralysis or paresis, often accompanied by weakness and the loss of feeling and uncontrolled body movements such as shaking
Role of palmar fascia/aponeurosis
Attachment site of palmaris longus & brevis
Protects and separates deeper structures
