Transcript Document 7204163

Chapter 16
Forearm, Wrist and Hand
Overview

The carpus, or wrist, represents a
highly complex anatomic structure,
comprising:
– A core structure of eight bones
– More than twenty radiocarpal, intercarpal,
and carpometacarpal joints
– Twenty-six named intercarpal ligaments
– The six or more parts of the triangular
fibrocartilage complex (TFCC)
Overview

The hand accounts for about 90% of upper
limb function
– The thumb is involved in 40-50% of hand
function
– The index finger is involved in about 20% of
hand function
– The middle finger, which accounts for about
20% of all hand function, is the strongest finger,
and is important for both precision and power
functions
Anatomy

Distal radio-ulnar joint
– A double pivot joint that unites the distal radius
and ulna and an articular disc (TFCC)
– The rounded head of the ulnar head contacts
both the ulnar notch of the radius laterally, and
the TFCC distally
– The ulnar styloid process is approximately onehalf inch shorter than the radial styloid process,
resulting in more ulnar deviation than radial
deviation
Anatomy

Triangular fibrocartilage complex (TFCC)
– The TFCC is essentially comprised of the
fibrocartilage disc interposed between the medial
proximal row and the distal ulna within the
medial aspect of the wrist
– The primary function of the TFCC is to improve
joint congruency and to cushion against
compressive forces

The TFCC transmits about 20% of the axial load from
the hand to the forearm
Anatomy

The Wrist
– Comprised of the distal radius and ulna, eight
carpal bones, and the bases of five metacarpals
– The carpal bones lie in two transverse rows
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The proximal row contains (lateral to medial) the
scaphoid (navicular), lunate, triquetrum, and pisiform
The distal row holds the trapezium, trapezoid, capitate,
and hamate
Anatomy

Mid Carpal Joints
– The midcarpal joint lies between the two rows of
carpals
– A ‘compound’ articulation because each row has
both a concave and convex segment
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The proximal row of the carpals is convex laterally and
concave medially.
The scaphoid, lunate, trapezium trapezoid, and
triquetrum present with a concave surface to the distal
row of carpals
The scaphoid, capitate and hamate present a convex
surface to a reciprocally arranged distal row
Anatomy

Carpal Ligaments
– The major ligaments of the wrist include
the palmar intrinsic ligaments, the volar
extrinsic and the dorsal extrinsic and
intrinsic ligaments
The extrinsic palmar ligaments provide the
majority of the wrist stability
 The intrinsic ligaments serve as rotational
restraints, binding the proximal row into a
unit of rotational stability

Anatomy

Radiocarpal Joint
– Formed by the large articular concave
surface of the distal end of the radius, the
scaphoid and lunate of the proximal
carpal row, and the TFCC
Anatomy

Antebrachial Fascia
– A dense connective tissue ‘bracelet’ that
encases the forearm and maintains the
relationships of the tendons that cross
the wrist
Anatomy

The Extensor Retinaculum
– This retinaculum serves to prevent the
tendons from ‘bow-stringing’ when the
tendons turn a corner at the wrist
– The tunnel-like structures formed by the
retinaculum and the underlying bones are
called fibro-osseous compartments
Anatomy

The extensor retinaculum compartments,
from lateral to medial, contain the tendons
of:
– Abductor pollicis longus and extensor pollicis
brevis
– Extensor carpi radialis longus and brevis
– Extensor pollicis longus
– Extensor digitorum and indicis
– Extensor digiti minimi
– Extensor carpi ulnaris
Anatomy

The Flexor Retinaculum
– Transforms the carpal arch into a tunnel,
through which pass the median nerve and some
of the tendons of the hand
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Proximally, the retinaculum attaches to the tubercle of
the scaphoid and the pisiform
Distally it attaches to the hook of the hamate, and the
tubercle of the trapezium
– In the condition known as ‘carpal tunnel
syndrome’ the median nerve is compressed in
this relatively unyielding space
Anatomy

Carpal Tunnel
– Serves as a conduit for the median nerve and
nine flexor tendons
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The palmar radiocarpal ligament and the palmar
ligament complex form the floor of the canal
The roof of the tunnel is formed by the flexor
retinaculum (transverse carpal ligament)
The ulnar and radial borders are formed by carpal
bones (trapezium and hook of hamate respectively)
Within the tunnel, the median nerve divides into a
motor branch and distal sensory branches
Anatomy

Tunnel of Guyon
– A depression superficial to the flexor
retinaculum, located between the hook of the
hamate and the pisiform bones

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The palmar (volar) carpal ligament, palmaris brevis
muscle, and the palmar aponeurosis form its roof
Its floor is formed by the flexor retinaculum
(transverse carpal ligament), pisohamate ligament, and
pisometacarpal ligament
– The tunnel serves as a passage way for the
ulnar nerve and artery into the hand
Anatomy

Phalanges
– Fourteen in number
– Each consist of a base, shaft, and head
Two shallow depressions, which correspond
to the pulley-shaped heads of the adjacent
phalanges, mark the concave proximal bases
 Two distinct convex condyles produce the
pulley-shaped configuration of the phalangeal
heads

Anatomy

Metacarpophalangeal (MCP) Joints of
the 2nd-5th Fingers
– The 2nd-5th metacarpals articulate with
the respective proximal phalanges in
biaxial joints
– The MCP joints allow flexion-extension
and medial-lateral deviation associated
with a slight degree of axial rotation
Anatomy

Carpometacarpal Joints
– Articulation between the distal borders of
the distal carpal row bones and the bases
of the metacarpals
– Stability of the CMC joints is provided by
the palmar and dorsal carpometacarpal
and intermetacarpal ligaments
Anatomy

First Carpometacarpal Joint
– Functionally the sellar (saddle-shaped)
carpometacarpal (CMC) joint is the most
important joint of the thumb
– Consists of the articulation between the
base of the first metacarpal and the distal
aspect of the trapezium
Anatomy

First Carpometacarpal Joint
– Motions that can occur at this joint
include flexion/extension,
adduction/abduction and opposition
(which includes varying amounts of
flexion, internal rotation, and palmar
adduction)
Anatomy

Metacarpophalangeal Joint of the
Thumb
– A hinge joint
– Consists of a convex surface on the head
of the metacarpal, and a concave surface
on the base of the phalanx
Anatomy

Interphalangeal (IP) Joints
– Adjacent phalanges articulate in hinge
joints that allow motion in only one plane
– The congruency of the IP joint surfaces
contributes greatly to finger joint stability
The proximal IP joint is a hinged joint capable
of flexion and extension
 The distal IP joint has similar structures but
less stability and allows some hyperextension.

Anatomy

Palmar Aponeurosis
– A dense fibrous structure continuous with the
palmaris longus tendon and fascia covering the
thenar and hypothenar muscles
– Dupuytren’s contracture is a fibrotic condition of
the palmar aponeurosis that results in nodule
formation or scarring of the aponeurosis, and
which may ultimately cause finger flexion
contractures
Anatomy

Extensor Hood
– A complex tendon, which covers the dorsal
aspect of the digits is formed from a
combination of the tendons of insertion from
extensor digitorum, extensor indicis, and
extensor digiti minimi
– Creates a ‘cable’ system that provides a
mechanism for extending the MCP and IP joints,
and allows the lumbrical, and possibly
interosseous muscles, to assist in the flexion of
the MCP joints
Anatomy

Synovial Sheaths
– Long narrow balloons filled with synovial
fluid, which wrap around a tendon so that
one part of the balloon wall (visceral
layer) is directly on the tendon, while the
other part of the balloon wall (parietal
layer) is separate
Anatomy

Flexor Pulleys
– Annular (A) and cruciate (C) pulleys restrain the
flexor tendons to the metacarpals and phalanges
and contribute to fibro-osseous tunnels through
which the tendons travel
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A1
A2
A3
A4
A5
from
from
from
from
from
the
the
the
the
the
MP joint and volar plate
proximal phalanx
PIP joint volar plate
middle phalanx
DIP joint volar plate
Anatomy

Muscles of the Wrist and Forearm
– Can be subdivided into the 19 intrinsic muscles
that arise and insert within the hand, and the 24
extrinsic muscles that originate in the forearm
and insert within the hand
– The flexors, located in the anterior compartment
flex the wrist and digits
– The extensors, located in the posterior
compartment, extend the wrist and the digits
Anatomy
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Anterior Compartment
– Superficial muscles
Pronator teres
 Flexor carpi radialis (FCR)
 Palmaris longus
 Flexor carpi ulnaris (FCU)
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Anatomy

Anterior Compartment
– Intermediate Muscle

Flexor Digitorum superficialis (FDS)
– Deep Muscles
Flexor pollicis longus (FPL)
 Flexor digitorum profundus (FDP)
 Pronator quadratus

Anatomy

Posterior Compartment
– Superficial muscles
Extensor
 Extensor
 Extensor
 Extensor

carpi radialis longus (ECRL)
carpi radialis brevis (ECRB)
digitorum and Extensor digiti minimi
carpi ulnaris (ECU)
Anatomy

Posterior Compartment
– Deep muscles
Abductor pollicis longus (APL)
 Extensor pollicis brevis (EPB)
 Extensor pollicis longus (EPL)
 Extensor indicis (EI)

Anatomy

Muscles of the Hand
– Short muscles of the thumb
Abductor pollicis brevis (APB)
 Flexor pollicis brevis (FPB)
 Opponens pollicis (OP)
 Adductor pollicis (AP)

Anatomy

Muscles of the Hand
– Short muscles of the 5th digit
Abductor digiti minimi (ADM)
 Flexor digiti minimi (FDM)
 Opponens digit minimi (ODM)

Anatomy

Muscles of the hand
– Interosseous muscles of the hand
Three palmar interossei. Each functions to
adduct the digit, to which it is attached,
toward the middle digit
 Four dorsal interossei. Each functions to
abduct the index, middle and ring fingers
from the mid-line of the hand

Anatomy

Muscles of the hand
– Lumbricales
Function to perform the motion of IP joint
extension with the MCP joint held in
extension
 Can assist in MCP flexion
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Anatomy

Anatomic Snuff Box
– A depression on the dorsal surface of the hand
at the base of the thumb, just distal to the
radius
– Formed by the tendons of the APL and EPB,
while the ulnar border is formed by the tendon
of the EPL
– Along the floor of the snuffbox is the deep
branch of the radial artery and the tendinous
insertion of the ECRL. Underneath these
structures, the scaphoid and trapezium bones
are found
Anatomy
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Functional arches of the hand
– The
– The
– The
– The
transverse arch
metacarpal arch
longitudinal arch
oblique arches
Anatomy

Neurology
– The three peripheral nerves that supply
the skin and muscles of the wrist and
hand include the median, ulnar, and radial
nerve
Anatomy

Vasculature of the wrist and hand
– The brachial artery bifurcates at the
elbow into radial and ulnar branches,
which are the main arterial branches to
the hand

Vascular arches of the hand
– Dorsal arches
– Palmar arches
Biomechanics

The wrist contains several segments
whose combined movements create a
total range of motion that is greater
than the sum of its individual parts
Biomechanics

Pronation
Approximately 90° of forearm pronation is
available
 During pronation, the concave ulnar notch of
the radius glides around the peripheral
surface of the relatively fixed convex ulnar
head
 Pronation is limited by the bony impaction
between the radius and the ulna

Biomechanics
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Supination
Approximately 85-90° of forearm supination is
available
 Supination is limited by the interosseous
membrane, and the bony impaction between
the ulnar notch of the radius, and the ulnar
styloid process
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Biomechanics

Wrist flexion and extension
– The movements of flexion and extension
of the wrist are shared among the
radiocarpal articulation, and the
intercarpal articulation, in varying
proportions
Biomechanics

Wrist flexion and extension
– During wrist flexion, most of the motion occurs
in the midcarpal joint (60% or 40° versus 40%
or 30° at the radiocarpal joint), and is associated
with slight ulnar deviation and supination of the
forearm
– During wrist extension, most of the motion
occurs at the radiocarpal joint (66.5% or 40°
versus 33.5% or 20° at the midcarpal joint), and
is associated with slight radial deviation and
pronation of the forearm
Biomechanics

Radial Deviation
– Radial deviation occurs primarily between
the proximal and distal rows of the carpal
bones
– The motion of radial deviation is limited
by impact of the scaphoid onto the radial
styloid, and ulnar collateral ligament
Biomechanics

Ulnar deviation
– Ulnar deviation occurs primarily at the
radiocarpal joint
– Ulnar deviation is limited by the radial
collateral ligament
Biomechanics

Thumb motions
– Within the first CMC joint, the longitudinal
diameter of the articular surface of the
trapezium is generally concave from a palmar to
dorsal direction
– The transverse diameter is generally convex
along a medial to lateral direction
– The proximal articular surface of the first
metacarpal is reciprocally shaped to that of the
trapezium
Biomechanics

Thumb flexion and extension
– Thumb flexion and extension occur
around an anterior-posterior axis in the
frontal plane that is perpendicular to the
sagittal plane of finger flexion and
extension
– In this plane, the metacarpal surface is
concave, and the trapezium surface is
convex
Biomechanics

Thumb abduction and adduction
– Thumb abduction and adduction occur
around a medial-lateral axis in the sagittal
plane, that is perpendicular to the frontal
plane of finger abduction and adduction
– During thumb abduction and adduction,
the convex metacarpal surface moves on
the concave trapezium
Biomechanics
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A number of grips have been recognized:
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Fist grip
Cylindrical grip
Ball grip
Hook grip
Ring grip
Pincer grip
Pliers grip
Examination

The examination of the forearm, wrist
and hand requires a sound knowledge
of differential diagnosis, and must
include an examination of the entire
upper kinetic chain, and the cervical
and thoracic spine
Examination

History
– The assessment of the forearm, wrist, and hand
begins by recording a detailed history
– The history helps focus the examination
– All relevant information must be gathered about
the site, nature, behavior and onset of the
current symptoms
– This should include information about the
patient’s age, hand dominance, avocational
activities, and occupation
Examination

Systems review
– The clinician should be able to determine the
suitability of the patient for physical therapy
– If the clinician is concerned with any signs or
symptoms of a visceral, vascular, neurogenic,
psychogenic, spondylogenic or systemic disorder
that is out of the scope of physical therapy, the
patient should be referred back to their physician
Examination

Observation
– The physical examination should begin with a
general observation of the patient’s postureespecially the cervical spine, and the thoracic
spine, and the position of hand in relation to the
body
– The contour of the palmar surface, including the
arches, should be examined
– If a finger is involved, its attitude should be
observed
Examination

Observation
– The clinician inspects for lacerations, surgical
scars, masses, localized swelling, or erythema
– Scars should be examined for degree of
adherence, degree of maturation, hypertrophy
(excess collagen within boundary of wound),
and keloid (excess collagen that no longer
conforms to wound boundaries)
– The location and type of edema should be noted
Examination

AROM, then PROM with over pressure
– The gross motions of wrist, hand, finger
and thumb flexion, extension, and radial
and ulnar deviation are tested, first
actively and then passively
– Any loss of motion compared with the
contralateral, asymptomatic wrist and
hand should be noted
Examination

Palpation
– Palpation of the muscles, tendon,
insertions, ligaments, capsules, bones of
the wrist and hand should occur as
indicated, and be compared with the
uninvolved side
Examination

Pain provocation tests
– These tests are used to determine the
cause of a painful or dysfunctional motion
by systematically testing each of the
articulations to see whether the
maneuvers reproduce the patient’s
symptoms
Examination

Strength testing
– Isometric tests are carried out in the extreme
range, and if positive, in the neutral range
– These isometric tests must include the interossei
and lumbricales
– The straight plane motions of wrist flexion,
extension, ulnar and radial deviation are tested
initially
– Pain with any of these tests requires a more
thorough examination of the individual muscles
Examination

Functional Assessment
– The functional range of motion for the
hand is the range in which the hand can
perform most of its grip and other
functional activities
– A number of assessment tools are
available
Examination

Passive Physiological Mobility Testing
– In each of the tests, the clinician
notes the quantity of motion as well
as the joint reaction (end feel).
– The tests are always repeated on,
and compared to, the same joint in
the opposite extremity
Examination

Passive Accessory Mobility Tests
– In each of the tests, the clinician notes
the quantity of accessory joint motion as
well as the joint reaction
– The tests are always repeated on, and
compared to, the same joint in the
opposite extremity
Examination

Ligament Stability
– A number of tests are available to
evaluate the ligamentous stability of the
forearm, wrist, hand and finger joints
Examination

Neurovascular Status
– Allen Test
– Tinel’s test for Carpal Tunnel Syndrome
Examination

Sensibility Testing
– The assessment of sensibility of the hand
is an important component of every hand
examination because sensation is
essential for precision movements and
object manipulation
– Two types of sensibility are assessed
Protective
 Functional

Examination
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Special tests
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Carpal Shake test
Sit to Stand test
Ulnar Impaction test
Finkelstein’s test
Flexor digitorum superficialis (FDS) test
Flexor digitorum profundus test
Extensor Hood rupture test
Froment’s sign
Murphy’s sign
Examination

Diagnostic testing
– Diagnostic testing of the forearm, wrist and hand
is limited to plain radiographs for most patients
– Bony tenderness with a history of trauma or a
suspicion of bone or joint disruption indicates a
need for radiographs
– Standard projections for the wrist are the
posteroanterior, lateral, and oblique
– For the patient with a suspicion of a scaphoid
injury, a scaphoid view should be added
Intervention Strategies

Acute phase goals:
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–
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Protection of the injury site to allow healing
Control pain and inflammation
Control and then eliminate edema
Restoration of pain-free range of motion in the entire kinetic
chain
Improve patient comfort by decreasing pain and inflammation
Retard muscle atrophy
Minimize detrimental effects of immobilization and activity
restriction
Scar management if appropriate
Maintain general fitness
– Patient to be independent with home exercise program
Intervention Strategies

Functional phase goals
– Attain full range of pain free motion
– Restore normal joint kinematics
– Improve muscle strength to within normal
limits
– Improve neuromuscular control
– Restore normal muscle force couple
relationships
Conditions