The Wrist and Hand Joints
The Wrist & Hand Joints
• Many sports require precise functioning
of wrist & hand
• Archery, bowling, golf, baseball,
tennis, etc. require combined use of
wrist & hand joints
• Relate functional anatomy to joint
actions
– flexion, extension, abduction, & adduction
of wrist & hand
– 29 bones
– More than 25 joints
– More than 30 muscles
• 18 are intrinsic
Bones
• 29 bones, including radius & ulna
– 8 carpal bones in 2 rows of 4 bones form
wrist
– 5 metacarpal bones, numbered 1 to 5 from
thumb to little finger, join the wrist
bones
– 14 phalanges (digits), 3 for each
phalange except the thumb, which has only
2
• Proximal, middle, & distal
– Thumb has a sesamoid bone in its flexor
tendon
O h idd i j i f
Bones
Eight carpal bones
• Proximal row from
radial to ulnar side
– scaphoid (boat-shaped)
or navicular
– lunate (moon-shaped)
– triquetrum (three-
cornered)
– pisiform (pea-shaped)
From Anthony CP, Kolthoff NJ: Textbook of anatomy and
physiology, ed 9, St Louis, 1975, Mosby.
Joints
• Wrist joint
– 70 to 90 degrees of flexion
– 65 to 85 degrees of extension
– 15 to 25 degrees of abduction
– 25 to 40 degrees of adduction
Joints
• Each finger has 3 joints
– Metacarpophalangeal (MCP) joints
– Proximal interphalangeal (PIP) joints
– Distal interphalangeal (DIP) joints
Joints
• Thumb has 2 joints
– Metacarpophalangeal (MCP) joint
• Full extension into 40 to 90 degrees
of flexion
• Ginglymus
Joints
• Thumb has 2 joints
– Interphalangeal (IP) joint
• Flex 80 to 90 degrees
• Ginglymus
Joints
• Thumb has 2 joints
– Carpometacarpal (CMC) joint of thumb
• Unique saddle-type joint
• 50 to 70 degrees of abduction
• Flex 15 to 45 degrees & extend 0 to 20
degrees
Movements
• Wrist
– Flexion & extension
– Abduction & adduction
• Fingers
– Flex & extend
– MCP joints also abduct & adduct
Movements
• Middle phalange is reference point to
differentiate abduction & adduction
– Thumb, index & middle fingers abduct when
they move laterally toward radial side of hand
– Ring & little fingers adduction when they move
medially toward ulnar side of hand
– Medial movement of thumb, index & middle
fingers toward ulnar side of hand is adduction
– Lateral movement of ring & little finger toward
radial side of hand is abduction
Movements
• Extension
– movement of back of hand
and/or phalanges toward
posterior or dorsal aspect
of forearm
Movements
• Abduction (radial
flexion)
– movement of thumb
side of hand toward
lateral aspect or
radial side of forearm
– Also, movement of
fingers away from
middle finger
Movements
• Adduction (ulnar flexion)
– movement of little finger
side of hand toward
medial aspect or ulnar
side of forearm
– Also, movement of
fingers toward middle
finger
Movements
• Opposition
– movement of thumb
across palmar aspect to
oppose any or all of the
phalanges
• Reposition
– movement of thumb as it
returns to anatomical
position from opposition
with hand and/or fingers
Flexor Carpi Radialis Muscle
Flexion of wrist
Abduction of wrist
Weak flexion of
elbow
Weak pronation
of forearm
Palmaris Longus Muscle
Flexion of wrist
Weak flexion
of elbow
Flexor Carpi Ulnaris Muscle
Flexion of wrist
Adduction of wrist,
together with
extensor carpi
ulnaris muscle
Weak flexion of
elbow
Extensor Carpi Ulnaris Muscle
Extension of
wrist
Adduction of wrist
together with flexor
carpi ulnaris muscle
Weak extension
of elbow
Extensor Carpi Radialis Brevis Muscle
Extension of
wrist
Abduction of wrist
Weak flexion of
elbow
Extensor Carpi Radialis Longus Muscle
Extension of
wrist
Abduction of
wrist
Weak flexion of
elbow
Weak pronation
to neutral
from a fully
supinated
position
Flexor Digitorum Superficialis Muscle
Flexion of fingers at
metacarpophalangeal
& proximal
interphalangeal joints
Flexion of wrist
Weak flexion
of elbow
Flexor Digitorum Profundus Muscle
Flexion of 4 fingers at
metacarpophalangeal,
proximal
interphalangeal, &
distal interphalangeal
joints
Flexion of wrist
Flexor Pollicis Longus Muscle
Flexion of thumb
carpometacarpal,
metacarpophalangeal,
& interphalangeal
joints
Flexion of wrist
Abduction of
wrist
Extensor Digitorum Muscle
Extension of 2nd, 3rd, 4th, Origin:
& 5th phalanges at Posteriolateral
metacarpophalangeal humeral epicondyle
joints
Insertion:
Extension of wrist Base of dorsal
aspect of middle &
Weak extension distal phalanxes
of elbow
Extensor Indicis Muscle
Extension of index finger at
metacarpophalangeal
joint
Weak wrist extension
Weak supination of
forearm from a
pronated position
Extensor Digiti Minimi Muscle
Extension of little finger
at
metacarpophalangeal
joint
Weak wrist extension
Weak elbow extension
Extensor Pollicis Longus Muscle
Extension of thumb at
carpometacarpal,
metacarpophalangeal, &
interphalangeal joint
Extension of wrist
Abduction of wrist
Weak supination of
forearm from a
pronated position
Extensor Pollicis Brevis Muscle
Extension of thumb at
carpometacarpal &
metacarpophalangeal
joints
Weak wrist extension
Wrist abduction
Abductor Pollicis Longus Muscle
Abduction of
thumb at
carpometacarpal
joint
Abduction of wrist
Extension of thumb at
carpometacarpal
joint
Weak supination of
forearm from a
pronated position
Weak flexion of wrist
