Download Wrist Hand Notes 1

Wrist & Hand I
Notes
The wrist joint is the articulation of the radius (on the thumb side of the wrist)
with the proximal row of carpal bones (mostly the scaphoid and lunate) and the
ulna and ulnar disc with the lunate and triquetrum. The wrist also includes the
proximal row of carpals (scaphoid, lunate, triquetrum) with the distal row of
carpals (trapezium, trapezoid, capitate, hamate). It is synovial joint, specific
classification being an ellipsoid joint. The movements possible are at two axes
and are flexion/extension and ab/adduction. Abduction and adduction are more
commonly referred to as radial deviation (abduction) and ulnar deviation
(adduction).
As usual, make sure to review the bones on either the A.D.A.M. CD or in the text.
Joint
wrist:
Classification
synovial:
ellipsoid joint
Movements Possible & Comments
flexion/extension (s-s axis/sagittal plane)
abduction/adduction (front-to-back axis/frontal
plane)
(1) distal radius and
ulna with proximal row
of carpals and (2)
proximal with distal row
of carpals
Lecture Slides
Left Distal Humerus - Anterior View
A - Medial epicondyle
B - Trochlea
C - Capitulum
D - Lateral Epicondyle
The wrist (and finger) flexors generally arise at least in part
from the medial epicondyle; the extensor arise from the
lateral epicondyle.
Flexor Carpi Radialis (FCR, red), Palmaris
longus (PL, yellow), Flexor Carpi Ulnaris (FCU,
green)
Prox Attachment: medial epicondyle
Distal Attachment: FCR, base of 2nd and 3rd
metacarpals; PL, palmar aponeurosis; FCU, pisiform
bone
Action: Together they flex the wrist; FCR with ECRL
& B radially deviate; FCU with ECU ulnarly deviates
Innervation: FCR - Median n. (C6, 7); FCU - Ulnar
n. (C8, T1)
Extensor Carpi Radialis Longus (ECRL, red)
and Brevis (ECRB, blue); Extensor Carpi
Ulnaris (ECU, yellow)
Prox Attachment: lateral epicondyle
Distal Attachment: ECRL & ECRB, bases of 2nd
and 3rd metacarpals; ECU, base of 5th metacarpal
Action: Together they extend the wrist; ECRL & B
with FCR radially deviate; ECU with FCU ulnarly
deviates
Innervation: Radial n. (ECRL & ECRB C6, 7; ECU
C7, 8)
Lab Pics
Anterior view of supinated right forearm; hand is
inferior:
Flexor Carpi Radialis (FCR, to your left), Flexor
Carpi Ulnaris (FCU, to your right)
Both are anterior to the wrist side-to-side axis for wrist
flexion/extension so function as wrist flexors. Axis for
ulnar/radial deviation is a front-to-back axis (as are all axes
for abduction/adduction) and is pictured in green. Neither
FCR or FCU travel through the axis so both function in
deviation. FCR travels to the radial side of the axis so radially
deviates the hand at the wrist joint. FCU travels to the ulnar
side and is an ulnar deviator.
Posterior view of pronated right forearm; hand is
superior:
Extensor Carpi Radialis Longus & Brevis (ECRL &
ECRB, to your left), Extensor Carpi Ulnaris (ECU, to
your right)
All three are posteriorr to the wrist side-to-side axis for wrist
flexion/extension and function as wrist extensors. Axis for
ulnar/radial deviation is a front-to-back axis and is pictured
in green. Neither ECRL or ECU travel through the axis, but
ECRB is very close to the axis in this example. ECRL and ECU
are knwon to be good deviators; ECRB is a poor deviator.
ECRL travels to the radial side of the axis so radially deviates
the hand at the wrist joint. ECU travels to the ulnar side and
is an ulnar deviator.