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Semester 4 FS Exam 3 > Biomechanics Wrist and Hand > Flashcards

Biomechanics Wrist and Hand Flashcards

1
Q

Wrist - elbow - shoulder relationship

A

Wrist works in conjunction with elbow and shoulder to allow optimal placement of hand in surrounding space

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2
Q

Wrist - in relation to length tension

A

The wrist optimizes the length tension relationships of the mm of the hand to allow for higher accuracy and effective functional use

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3
Q

What is responsible for carrying the work of the UE

A

hand

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4
Q

Diversity in tasks require

A

ROM, force, sensitivity

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5
Q

What allows for efficiency

A

Synergy among the wrist/hand structures

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6
Q

Forearm bones

A

Radius

Ulna

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7
Q

Hand bones

A

Carpals (wrist)
Metacarpals (palm)
Phalanges (fingers)

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8
Q

How many bones of the hand and the breakdown

A

27 bones
8 carpals
5 metacarpals
14 phalaneges

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9
Q

Proximal row of carpals from radial to ulnar side

A

Scaphoid, lunate, triquetral, pisiform

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10
Q

Distal row of carpals from radial to ulnar side

A

Trapezium, trapezoid, capitate, hamate

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11
Q

Anteriorly (palmar) what shape is the hand

A

Concave

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12
Q

What does the proximal row of carpals make

A

condyle type structure

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13
Q

Base of all the carpals is the

A

capitate

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14
Q

Metacarpals - parts

A

Proximal (base)
Body
Distal (head)

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15
Q

Phalanges - parts

A

Proximal
Middle
Distal

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16
Q

Phalanges - thumb

A

Only has 2 phalanges

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17
Q

Radiocarpal joint - why is it called that

A

Connects the radius to the carpal bones

Dropped the ulna because ulna doesnt directly contact the carpal bones (disc does)

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18
Q

What type of joint is the radiocarpal joint and how many DOF

A

Condyloid

2 DOF

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19
Q

Movements of the Radiocarpal joint and what plane they are on

A

Flex/Ext = sagittal
Rad/Uln Dev = frontal
Some degree of circumduction

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20
Q

Circumduction of the radiocarpal joint is facilitated by

A

pronation and supination

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21
Q

radiocarpal joint - rotation

A

NOT possible due to oblong shape of radius

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22
Q

Joint surfaces of the radiocarpal joint- proximal

A

Distal radius and the radioulnar disc = biconcave

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23
Q

Joint surfaces of the radiocarpal joint - distal

A

Convex

Scaphoid, lunate, triquetrum

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24
Q

Joint surfaces of the radiocarpal joint - lateral facet

A

Scaphoid

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25
Q

Joint surfaces of the radiocarpal joint - medial

A

Lunate

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26
Q

Joint surfaces of the radiocarpal joint - disc

A

triquetrum

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27
Q

What encloses the radiocarpal joint

A

fibrous capsule

From the distal radius and ulna to the proximal row of carpals

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28
Q

Arthrokinematics of the radiocarpal joint - open chain

A

Carpals on the radius/disc

Convex on concave

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29
Q

Arthrokinematics of the radiocarpal joint - closed chain

A

Radius/disc on the carpals

Concave on convex

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30
Q

Ulnar tilt

A

The articular surface of the radius (anteriorly) faces in the ular direction MEDIALLY about 25 degrees

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31
Q

Radial tilt

A

The radial surface shows a palmar tilt - facing a little ANT

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32
Q

Distal articular surface of the radius to the carpals faces what directions

A

Slightly med and ant

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33
Q

Midcarpal joint - describe it

A

distal row of carpals moving on the proximal row of carpals

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34
Q

Midcarpal joint - which is convex and which is concave

A

Convex distal row of carpals moving on the Concave proximal row of carpals

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35
Q

What type of joint is the midcarpal joint and how many DOF

A

Condyloid

2 DOF

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36
Q

Midcarpal joint - movements

A

Flex/Ext

Radial/Ulnar deviation

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37
Q

Plane for Flex/Ext of the midcarpal joint

A

Sagittal plane

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38
Q

Plane for Rad/Uln deviation of the midcarpal joint

A

Frontal plane

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39
Q

Joint surfaces of the midcarpal joint - Proximal

A

Scaphiod, lunate, triquetrum

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40
Q

Joint surfaces of the midcarpal joint - Distal

A

Trapezium, trapezoid, capitate, hamate

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41
Q

Intercarpal joints

A

Located between the individual carpal bones

Gliding movement btw them allows for inc ROM at the wrist

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42
Q

Volar (palmar) radiocarpal ligaments

A

Radiocapitate
Radiotriquetral
Radioscaphoid
Radiolunate

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43
Q

Function of the radiocapitate ligament

A

Stabilize the lunate and scaphoid

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44
Q

Function of the radiotriquetral

A

Stabilize the lunate

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45
Q

Volar (palmar) ulnocarpal ligaments

A

Ulnocapitate
Ulnolunate
Ulnotriquetral

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46
Q

Volar radiocarpal AND Volar ulnocarpal ligaments - what do they do

A

Limit extension

Prevent separation of the carpals - creates stability among the carpal bones

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47
Q

Wrist joint ligaments

A

Dorsal radiocarpal
Ulnar collateral
Radial collateral

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48
Q

Dorsal radiocarpal ligament goes where

A

from the radial styloid to the lunate and triquetrum

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49
Q

Dorsal radiocarpal ligament limits what

A

Limits flexion

Prevents separation of the carpals

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50
Q

Ulnar collateral ligament goes from where

A

From ulna to pisiform and triquetrum

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51
Q

Ulnar collateral ligament limits what

A

limits radial deviation

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52
Q

Radial collateral ligament goes from where

A

From radius to scaphoid, trapezium, and 1st metacarpal

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53
Q

Radial collateral ligament limits what

A

ulnar deviation

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54
Q

Arthrokinematics - wrist - Flexion vs. Extension ROM - which do we have more of

A 
More flexion (80-85 degrees)
Extension (70-80)
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55
Q

Arthrokinematics - wrist - Radial vs. Ulnar Deviation ROM - which do we have more of

A

Moe ulnar deviation (30-45)

radial (15-25)

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56
Q

Arthrokinematics - wrist - ROM - why do we have more ulnar deviation than radial

A

The distal radius faces medially (ulnar tilt)

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57
Q

Close packed position of the radiocarpal joint

A

Full extension and radial deviation (the motions we have less of)

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58
Q

Close packed position of the midcarpal joint

A

Full extension

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59
Q

Open packed position of the radiocarpal joint

A

Neutral with slight ulnar deviation

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60
Q

Open packed position of the midcarpal joint

A

Slight flexion and ulnar deviation

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61
Q

Axis of motion in for the wrist joints

A

With ext = is more distal
With flex = is more proximal
Deviates because of the motion in the carpal bones

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62
Q

Wrist - sequence from flexion into extension

A
  1. movement initiated from distal carpal row (capitate)
  2. distal carpals glide on prox carpals in same direction as hand
  3. At neutral, volar radioscaphoid and radiocapitate ligaments tighten and pull distal row of carpals into close packed
  4. At 45 degrees of ext, the volar radioscaphoid and radiolunate ligaments tighten and pull lunate into close packed on scaphoid
  5. Remaining motion in ext is via both rows of carpals moving together as a solid unit on radius and disc
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63
Q

Wrist - sequence from extension into flexion

A

MAKE CARD ONCE UNDERSTAND :(

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64
Q

Wrist - sequence for radial deviation

A
  1. Mvmnt initiated at distal carpal row
  2. Distal carpal row moves back towards the radius
  3. Ligaments on ulnar side tighten
  4. Prox carpal row moves in ulnar direction
  5. Scaphoid and Zium approach radial styloid
  6. Scaph forced into flex (ant)
  7. Ligament between scaph and lunate pulls lunate into flex
  8. Radial deviation continues with proximal row ulnar glide
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65
Q

Wrist - sequence for ulnar deviation

A
  1. Mvmnt initiated at distal carpal row
  2. Distal carpal row moves towards the ulna
  3. Ligaments on radial side tighten
  4. Prox row moves in radial direction
  5. Triquetrum forced into hamate
  6. Hamate pulled prox by ligament tension
  7. Ligament tenstion pulls scaphoid and lunate into ext
  8. Ulnar deviation continues until stopped by ligaments
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66
Q

Flexor carpi radialis - action and location

A

Flexion of the wrist and radial deviation

On ant side predominantly - the distal aspect is on the radial side

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67
Q

Flexor carpi ulnaris - action and location

A

Flexion of the wrist and ulnar deviation

Starts on medial epicondyle and stays on medial side of the forearm

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68
Q

Plamaris longus - action

A

flex the wrist

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69
Q

Flexor digitorum superficialis - action

A

flex the wrist and fingers to the PIP

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70
Q

Flexor digitorum profundus - where does it start and attach

A

proximal shaft of the ulna to the distal phalanges 2-5

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71
Q

Flexor digitorum profundus - actions

A

Will flex the wrist, flex the fingers all the way and can contribute into ulnar deviation too

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72
Q

How does the flexor digitorum profundus contribute into ulnar deviation

A

Because the radiocarpal joint is oriented medially so when it pulls, it pulls into ulnar deviation

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73
Q

Extensor digitorum - where do the tendons connect

A

To the aponeurotic hood

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74
Q

Action of the extensor digitorum

A

Ext wrist and fingers all the way (2-5)

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75
Q

Function of the aponeurotic hood

A

Make sure that the force of the tendons gets pulled into only extension

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76
Q

Extensor carpi radialis longus - action

A

Radial deviation and extension

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77
Q

Extensor carpi radialis brevis - action

A

Radial deviation and extension

78
Q

Location difference of extensor carpi radialis brevis and longus

A

Longus starts more proximal on the humerus and the brevis starts on the condyle

79
Q

Extensor carpi ulnaris - action

A

Extension and ulnar deviation

80
Q

The carpal tunnel contains

A 
Flexor digitorum superficialis
Flexor digitorum profundus 
Flexor pollicis longus
Flexor carpi radialis
Median nerve
81
Q

Flexor retinaculum - distally - from where to where

A

Trapezium to hook of hamate

82
Q

Flexor retinaculum - proximally - from where to where

A

Scaphoid with triquetrum

83
Q

Which end (prox or distal) is the flexor retinaculum tighter

A

Tighter at proximal end

84
Q

The carpal arch is maintained by the

A

flexor retinaculum (transverse carpal ligament) and the transverse intercarpal ligament

85
Q

Arches of the wrist and hand - name them

A

Longitudinal
Transverse
Oblique

86
Q

Longitudinal arches of the hand
from where?
centered where?

A

From carpal bones to tip of phalanges

Centered around 3rd digit

87
Q 
Transverse arches of the hand
Proximal?
Distal?
Serve for:
Keyston
A

Proximal - distal row of carpal bones
Distal - through heads of metacarpals
Serve for mobility of the hand - wrist and finger flexion
Keystone = capitate

88
Q

Oblique arches of the hand

A

Digits move in an oblique fashion to thumb/carpals

Thumb opposition to fingers

89
Q

Joints of the hand include

A

Carpometacarpal
Metacarpophalangeal
Interphalangeal (proximal and distal)

90
Q

2nd CMC joint - type of joint and DF

A

Plane, 1 DF (FLEX/EXT)

91
Q

2nd CMC joint is made of what

A

Trapezium
Trapezoid
Capitate
3rd MC

92
Q

3rd CMC joint - type of joint and DF

A

Plane, 1 DF (FLEX/EXT)

93
Q

3rd CMC joint is made of what

A

Capitate

2nd and 4th MC

94
Q

4th CMC joint is what type and DF

A

Plane, 1 DF (FLEX/EXT)

95
Q

4th CMC joint is made of what

A

Hamate
Capitate
3rd and 5th MC

96
Q

5th CMC joint is what type and DF

A

Saddle, 2 DF (FLEX/EXT and ABD/ADD)

97
Q

5th CMC joint is made of what

A

Hamate

4th MC

98
Q

All CMC joints are supported by

A

Strong transverse ligaments and weaker longitudinal ligaments volarly and dorsally

99
Q

CMC joint 2-5 motion - pattern

A

Motion increases from radial to ulnar (2-5)

2 and 3 are immobile

100
Q

CMC of the thumb - bones

A

Trapezium, first metacarpal

101
Q

CMC of the thumb - type of joint

A

Sellar - Saddle shaped

Concave and convex at the same time

102
Q

Ligaments of the CMC of the thumb

A

Capulse
Radial CMC (lateral)
Ant and Post oblique

103
Q

Stabilizing factors of the CMC of the thumb

A

Surface shape
Muscles
Ligaments

104
Q

Type of motion of the CMC of the thumb - how many DF

A

3 DF
Flex/Ext
Abd/Add
Limited axial rotation, but there is circumduction

105
Q

Trapezium is __ in the ___ plane and ___ in the ___ plane

A

Concave in the sagittal plane

Convex in the frontal plane

106
Q

Movements of the CMC joint of the thumb - what makes up opposition

A

Flexion + abduction + internal rotation

107
Q

1st MCP joint (thumb) - what is it

A

The head of the 1st MC bone with the base of the proximal phalanx

108
Q

What type of joint is the 1st MCP and how many DF

A

Condyloid - 2 DF
FLEX/EXT and ABD/ADD
Motion is significantly restricted though

109
Q

1st MCP joint motion
Ext =
Flex =
Ab/Ad =

A

0 Ext
50-60 Flex
5-10 of total ab/ad

110
Q

1st MCP - supported by

A

collateral and intersesmoid ligaments

111
Q

2nd to 5th MCP joints - what are they

A

Head of the MC bones to the base of the proximal phalanx

112
Q

2nd to 5th MCP joints - what type of joint and DF

A

Condyloid - 2 DF

FLEX/EXT and ABD/ADD

113
Q

2nd to 5th MCP joints - articulating surfaces

A

Concave phalanx (20 degrees of articulating surface)
Convex MC bone (180 degrees of articulating surface)
Difference contributes to hyperextension and axial rotation

114
Q

2nd to 5th MCP joints - motion increases from

A

radial to ulnar side

115
Q

2nd to 5th MCP joints
Ex:
Flex:
Ab/Add:

A

40 of ext
90-110 of flex
20 total of ab/add

116
Q

Close packed position of the 2nd to 5th MCP joints

A

Full flexion

117
Q

2nd to 5th MCP joints - volar ligament does what

A

Enhances joint stability and prevents hyperextension

118
Q

2nd to 5th MCP joints - collateral ligaments do what

A

Limit radial and ulnar deviations as well as flexion

119
Q

2nd to 5th MCP joints - axial rotation requires what

A

Is a passive movement

120
Q

IP joints - type

A

Synovial hinge - FLEX/EXT

121
Q

IP joints - what on what

A

Concave base on convex head

122
Q

IP - joints - Proximal (convex) articulating surface faced ____ this results in what?

A

Faced volarly

Results in higher flexion and decreased extension

123
Q

PIPs: Flex and Ext

A 
Ext = 0
Flex = 100-135
124
Q

DIPs: Flex and Ext

A 
Ext = 10
Flex = 80-90
125
Q

IP joints - increase movement in which direction (radially or ulnarly)
What does it facilitate

A

Inc ulnarly - which facilitates opposition and convergence

126
Q

Close packed position of the IP joints

A

Full extension

127
Q

Ligaments of the IP joints

A

Volar ligament

Collateral ligaments

128
Q

Function of the ligaments of the IP joint

A

Volar - enhances joint stability, prevents hyperextension

Collateral - tight through range

129
Q

Arthrokinematics of active Ext, Flex, Abd

A

Concave on convex - Roll and glide in the same direction

130
Q

Intrinsic muscles of the hand

A 
Thenar
Hypothenar
Lumbricals
Dorsal interossei
Palmar interossei
131
Q

Thenar muscles

A

Abductor pollicis brevis
Opponens pollicis
Flexor pollicis brevis
Adductor pollicis

132
Q

Hypothenar muscles

A

Abductor digiti minimi
Opponens digiti minimi
Flexor digiti minimi

133
Q

Lumbricals - how many and action

A

4 of them
Flex MCP
Ex IP
Radial deviation of the MCP

134
Q

Weakness of the lumbricals contributes to

A

claw hand (in conjunction with the dorsal interossei)

135
Q

Dorsal interossei - how many and action

A

4 of them

Abd

136
Q

Weakness of the dorsal interossei

A

Weakness in abd of index, long and ring fingers

Loss of muscle balance and grip strength

137
Q

Palmar interossei - how many and action

A

3-4 of them

Add

138
Q

Palmar interossei - weakness

A

Weakness in Add/convergence of fingers

Loss of muscle balance and grip strength

139
Q

Prehension - define

A

The act of gripping something with the hand

140
Q

Precision grip - when used

A

Use when fine movements are needed

Great strength is not available

141
Q

Precision grip - mainly involves what

A

index finger and thumb

Only radial side is involved

142
Q

Precision grip - different types

A

Tip to tip
Pad to pad
Pad to side
Three point

143
Q

Power grip - when used

A

Used where strength is needed

Fine movements are not available

144
Q

Power grip - mainly involves what

A

Flexion of all fingers

All digits and palm are involved

145
Q

Power grip - different types

A

Palmar grip

Hook grip

146
Q

Distinguishing factors between power and precision grips

A 
Area of contact within the hand
Number of fingers involved in the activity 
Amount of finger flexion
Position of the thumb
Position of the wrist
147
Q

Muscles involved in tip to tip

A

Thumb - opposition

MCP, PIP and DIP flexed

148
Q

Muscles involved in pad to pad

A

Thumb - opposition
MCP, PIP flexed
DIP extended

149
Q

Muscles involved in pad to side

A

Thumb - approaches 2nd and 3rd fingers

Stronger pinch when more power is required

150
Q

Types of power grip/grasp - joint positions vary with type of grasp - what impacts grasp pattern

A

Size of the object

151
Q

Types of power grip/grasp - joint positions vary with type of grasp - Fingers more flexed on which side

A

Ulnar side

152
Q

Types of power grip/grasp - joint positions vary with type of grasp - what acts as a stabilizer and how

A

Thumb - it tends to flex over the other fingers

153
Q

Types of power grip/grasp - joint positions vary with type of grasp - What pulls the thumb onto the fingers and/or object

A

Adductor pollicis brevis

154
Q

What is often associated with a palmar or cylindrical grip

A

Ulnar deviation

155
Q

Extensor assembly provides what

A

Optimal alignment of the ED tendon
Assists in producing proper moment arms during extension
Allows for smooth coordinated finger flexion

156
Q

Extensor assembly - Ext digitorum tendon attaches to what

A

Aponeurotic hood

157
Q

Extensor assembly - dorsal and palmar interossei attach where

A

aponeurosis

158
Q

Extensor assembly - lumbricals attach where

A

aponeurosis

159
Q

Extensor assembly - hood distal structure - how many segments

A

3
Central tendon
2 lateral bands separate and reunite to the central tendon

160
Q

Flexor tendon, sheaths, and pulleys - FDS attaches where

A

to the middle phalanx

and splits into two bands forming a tunnel for the FDP

161
Q

Flexor tendon, sheaths, and pulleys - FDP attaches where

A

to the distal phalanx

162
Q

Flexor tendon, sheaths, and pulleys - how many pulleys

A

5 annular and 3 cruciform

163
Q

Flexor tendon, sheaths, and pulleys - function of the pulleys

A

Maintain a constant moment arm of the tendon

164
Q

Flexor tendon, sheaths, and pulleys - damage of the pulleys contributes into what

A

Bowstringing

  • amplification of torque produced
  • reduction of angular motion of the joint
165
Q

Wrist extensor role in grip strength - with the wrist flexed –>

A

Flexors cant generate adequate force (they are too short)

Overstretch extensors create a passive extensor torque

166
Q

Wrist extensor role in grip strength - with the wrist extended

A

flexors cant generate adequate force (too long)

167
Q

Wrist extensor role in grip strength - where is the optimal position for best grip strength

A

about 35 degrees extension optimizes the length-tension curve of the extrinsic finger flexors

168
Q

Paralyzed wrist extensors results in

A

ineffective grip strength

169
Q

Hand: stability/control mechanisms

A

Ligamentus system
Extensor assembly
Flexor tendon sheaths and pulleys

170
Q

Hand: stability/control mechanisms - ligamentus system

A 
Collateral ligaments (radial and ulnar)
Volar plate
Thick volar joint capsules (IP joints)
Arches of the hand
Thick volar skin 
Thin dorsal capsules (MCP and IP joints)
171
Q

Hand: stability/control mechanisms - Extensor assembly

A

Tendinous structures of the ED and the intrinsic muscle insertions

172
Q

Hand: stability/control mechanisms - Flexor tendon sheaths and pulleys

A

Attachments of the FDS and FDP surrounding retinacula, tendon sheaths and pulleys

173
Q

Balance of muscle forces in the hand - tendon excursions occur

A

simultaneously and in opposite directions

174
Q

Balance of muscle forces in the hand - Tendon moment arms and excursions decrease from

A

Proximal to distal joints
FDS - FDP
FL - EXT
Extrinsic - Intrinsic

175
Q

Balance of muscle forces in the hand - During flex/ext what acts as moderators

A

Intrinsic muscles

They stabilize the middle phalange

176
Q

Balance of muscle forces in the hand - use of FDP versus FDS

A

FDP used more frequently

FDS used as more power is needed

177
Q

Balance of muscle forces in the hand - only muscle that produces MCP ext is what

A

ED

If intrinsic muscles are inactive, ED produces clawing

178
Q

Balance of muscle forces in the hand - DIP movement is tied to what

A

PIP movement

Full flexion of PIP prevents DIP active extension

179
Q

Tenodesis - define

A

an action that is used as a substitute to a proper, finger flexing grasp

180
Q

Tenodesis - when the wrist is extended…

A

the fingers naturally fall into position of flexion and the thumb into opposition with the index finger

181
Q

Tenodesis - process used

A
  1. Wrist placed in flexion using gravity
  2. Object placed between thumb and finger
  3. Active wrist extension to pick up object
  4. Wrist extension maintained to transfer object
  5. Object released by relaxing extension and allowing hand to open
182
Q

Opening the hand sequence - Early phase

A

ED

183
Q

Opening the hand sequence - Middle phase

A

Lumbricals

Interossei

184
Q

Opening the hand sequence - Late phase

A

ED and intrinsic

Flexor carpi radialis

185
Q

Opening the hand sequence - pattern is

A

Proximal to distal

186
Q

Opening the hand sequence - hood migration

A

Dorsal hood migrates proximally

187
Q

Closing the hand sequence - early phase

A

FDP
FDS
Interossei

188
Q

Closing the hand sequence - late phase

A

FDP
FDS
Interossei
Lumbricals remain inactive (stretched)

189
Q

Closing the hand sequence - pattern is

A

Distal to proximal

190
Q

DON’T FORGET TO SMILE

A

:D

Semester 4 FS Exam 3 (1 decks)

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