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
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

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 Deep Muscles
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 Vascular arches of the 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 patient’s 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 patient’s 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 patient’s 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
Tinel’s 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
Finkelstein’s test
Flexor digitorum superficialis (FDS) test
Flexor digitorum profundus test
Extensor Hood rupture test
Froment’s sign
Murphy’s 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