Forearm, Wrist and Hand

1
Chapter 16

• Forearm, Wrist and Hand

2
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)

3
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

4
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
  one-half inch shorter than the radial styloid
  process, resulting in more ulnar deviation than
  radial deviation

5
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

6
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
• The proximal row contains (lateral to medial) the
  scaphoid (navicular), lunate, triquetrum, and
  pisiform
• The distal row holds the trapezium, trapezoid,
  capitate, and hamate

7
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
• 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

8
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

9
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

10
Anatomy

• Antebrachial Fascia
• A dense connective tissue bracelet that encases
  the forearm and maintains the relationships of
  the tendons that cross the wrist

11
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

12
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

13
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
• 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

14
Anatomy

• Carpal Tunnel
• Serves as a conduit for the median nerve and nine
  flexor tendons
• 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

15
Anatomy

• Tunnel of Guyon
• A depression superficial to the flexor
  retinaculum, located between the hook of the
  hamate and the pisiform bones
• 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

16
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

17
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

18
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

19
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

20
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)

21
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

22
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.

23
Anatomy

• Palmar Aponeurosis
• A dense fibrous structure continuous with the
  palmaris longus tendon and fascia covering the
  thenar and hypothenar muscles
• Dupuytrens 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

24
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

25
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

26
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
• A1 from the MP joint and volar plate
• A2 from the proximal phalanx
• A3 from the PIP joint volar plate
• A4 from the middle phalanx
• A5 from the DIP joint volar plate

27
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

28
Anatomy

• Anterior Compartment
• Superficial muscles
• Pronator teres
• Flexor carpi radialis (FCR)
• Palmaris longus
• Flexor carpi ulnaris (FCU)

29
Anatomy

• Anterior Compartment
• Intermediate Muscle
• Flexor Digitorum superficialis (FDS)
• Deep Muscles
• Flexor pollicis longus (FPL)
• Flexor digitorum profundus (FDP)
• Pronator quadratus

30
Anatomy

• Posterior Compartment
• Superficial muscles
• Extensor carpi radialis longus (ECRL)
• Extensor carpi radialis brevis (ECRB)
• Extensor digitorum and Extensor digiti minimi
• Extensor carpi ulnaris (ECU)

31
Anatomy

• Posterior Compartment
• Deep muscles
• Abductor pollicis longus (APL)
• Extensor pollicis brevis (EPB)
• Extensor pollicis longus (EPL)
• Extensor indicis (EI)

32
Anatomy

• Muscles of the Hand
• Short muscles of the thumb
• Abductor pollicis brevis (APB)
• Flexor pollicis brevis (FPB)
• Opponens pollicis (OP)
• Adductor pollicis (AP)

33
Anatomy

• Muscles of the Hand
• Short muscles of the 5th digit
• Abductor digiti minimi (ADM)
• Flexor digiti minimi (FDM)
• Opponens digit minimi (ODM)

34
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

35
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

36
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

37
Anatomy

• Functional arches of the hand
• The transverse arch
• The metacarpal arch
• The longitudinal arch
• The oblique arches

38
Anatomy

• Neurology
• The three peripheral nerves that supply the skin
  and muscles of the wrist and hand include the
  median, ulnar, and radial nerve

39
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

40
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

41
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

42
Biomechanics

• 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

43
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

44
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

45
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

46
Biomechanics

• Ulnar deviation
• Ulnar deviation occurs primarily at the
  radiocarpal joint
• Ulnar deviation is limited by the radial
  collateral ligament

47
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

48
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

49
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

50
Biomechanics

• A number of grips have been recognized
• Fist grip
• Cylindrical grip
• Ball grip
• Hook grip
• Ring grip
• Pincer grip
• Pliers grip

51
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

52
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
  patients age, hand dominance, avocational
  activities, and occupation

53
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

54
Examination

• Observation
• The physical examination should begin with a
  general observation of the patients
  posture-especially 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

55
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

56
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

57
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

58
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 patients symptoms

59
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

60
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

61
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

62
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

63
Examination

• Ligament Stability
• A number of tests are available to evaluate the
  ligamentous stability of the forearm, wrist, hand
  and finger joints

64
Examination

• Neurovascular Status
• Allen Test
• Tinels test for Carpal Tunnel Syndrome

65
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

66
Examination

• Special tests
• Carpal Shake test
• Sit to Stand test
• Ulnar Impaction test
• Finkelsteins test
• Flexor digitorum superficialis (FDS) test
• Flexor digitorum profundus test
• Extensor Hood rupture test
• Froments sign
• Murphys sign

67
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

68
Intervention Strategies

• Acute phase goals
• 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

69
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

70
Conditions