Wrist and Hand Biomechanics Flashcards
1
Q
What is prehension
A
Grip
2
Q
True or False:
You need proximal stability for distal mobility
A
True
3
Q
True or False:
The UE is subservient to the wrist and hand
A
True
4
Q
Is compensation proximally for lost hand function effective
A
Nope
5
Q
How many degrees of freedom does the humeroulnar joint have
A
1
6
Q
During CKC pronation and supination what is moving
A
Ulna rotates on a fixed radius
7
Q
Fewer degrees of freedom means there is more mobility or stability
A
Stability
8
Q
What is AOM
A
Analysis of Motion
9
Q
How can the ulna rotate on the radius during CKC supination and pronation
A
The ulna has no articulation with the wrist
10
Q
Where is the expansion of the radius
A
At the carpus
11
Q
What is the purpose of the expansion of the radius and ulna
A
Attachment of muscles, tendons, and ligaments
12
Q
Where is the ulnar expansion
A
At the humerus
13
Q
The ulna at the carpus is modified for what
A
Radius and hand to rotate
14
Q
The space at the distal end of the ulna is called what
A
Ulnocarpal space
15
Q
What is in the ulnocarpal space
A
Triangular Firbrocartilage Complex (TFC)
16
Q
Where does the stability of the hand come from
A
3rd metacarpal and somewhat the 2nd metacarpal
17
Q
What is the 3rd metacarpal flanked by
A
Mobile segments
18
Q
What is the thenar eminence
A
Thumb side muscularture
19
Q
What is the hypothenar eminence
A
Pink side musculature
20
Q
What muscles are present at the 2nd and 3rd metacarpals to provide stability at the wrist allowing for freedom of movement around the pillar (3)
A
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Flexor carpi radialis
21
Q
Which carpal is most inportant
A
Capitate
22
Q
What type of motion occurs at the wrist complex
A
Biaxial
23
Q
What are the planes motion occurs in at the wrist complex
A
Frontal and sagittal
24
Q
What are the sagittal plane motions
A
Flexion and extension
25
What is the range for flexion and extension at the wrist complex
Flexion: 80-90
Extension: 70-80
26
What are the frontal plane motions
Ulnar and radial deviation
27
What is the range for ulnar and radial deviation
Ulnar: 30-35
Radial: 20-25
28
Why is radial deviation less than ulnar deviation
Due to the size of the radial styloid
29
What makes up the proximal articulation of the radiocarpal joint
Radius and radioulnar disc (TFC)
30
What makes up the distal articulation of the radiocarpal joint
Scaphoid, lunate, triquetrium
31
What are the arthronkinematics of the radiocarpal joint
Convex scaphoid and lunate moving on a concave distal radius
32
What does the lateral radial facet articulate with and percent of the radiocarpal joint
Scaphoid, 46%
33
What does the medial radial facet articulate with and percent of the radiocarpal joint
Lunate, 43%
34
What does the inferior radioulnar disc articulate with and percent of the radiocarpal joint
Triquetrium, 11%
35
True or False:
| There is no formal carpal articulation with the ulna
True
36
Is the pisiform included in the radiocarpal joint
No
37
What type of bone is the pisiform bone
Sesamoid bone
38
What does the pisiform do
Increase MA of the flexor carpi ulnaris
39
What does a sesamoid bone do
Enhances MA of muscles
40
True or False:
| No muscles act directly on the RC joint
True
41
What is motion at the radiocarpal joint due to
Ligamentous forces distributed and muscles that insert at the distal carpals and metacarpals
42
What 2 motions does the radiocarpal joint contribute to most
Flexion and ulnar deviation
43
If someone has flexion and ulnar deviation problems what joint should you focus on
Radiocarpal joint
44
True or False:
| The midcarpal joint has no isolated capsule
True
45
How would you describe the midcarpal joint
Interrupted multiarticular surface
46
True or False:
| The scaphoid contributes to motion both at the radiocarpal and midcarpal joints
True
47
How many degrees of freedom does the midcarpal joint have
2
48
What 2 motions does the midcarpal joint contribute to most
Extension and radial deviation
49
True or False:
| The intercarpal joints allow minimal movement to accomodate hand and wrist positioning
True
50
Which side of the intercarpal joints is more mobile
Ulnar side
51
What ligaments of the intercarpal joints are stronger palmar or dorsal ligaments
Palmar ligaments
52
True or False:
| The palmar side of the lunate is reltively unstable
True
53
Which carpal is the most commonly dislocated
Lunate
54
Does the scaphoid have any ligament attachment dorsally near the proximal pole
No
55
What does the lack of ligament attachment on the proximal pole of the scaphoid potentially lead to
Ganglion cyst formation
56
True or False:
| Ligaments are support structures and passive movers
True
57
What does the dorsal radiocarpal ligament contact
Lunate and radius
58
What is the dorsal radiocarpal ligament a check rein to
End range wrist flexion
59
What are the ulnar and radial collateral ligaments check reins to
Radial: Ulnar deviation
Ulnar: Radial deviation
60
True or False:
| The volar radiocarpal ligament is the most important of all ligaments for stability and passive mobility contribution
True
61
How many bands does the volar radiocarpal ligament have
3
62
What is the coupled motion with flexion
Ulnar deviation
63
What is the coupled motion with extension
Radial deviation
64
What is the angle of the radial head called
Ulnar tilt
65
What is the angle of the radial head
25
66
During flexion at the radiocarpal joint what arthrokinematics occur
Palmar roll and dorsal glide
67
During extension at the radiocarpal joint what arthrokinematics occur
Dorsal roll and palmar glide
68
During radial deviation at the radiocarpal joint what arthrokinematics occur
Radial roll and ulnar glide
69
During ulnar deviation at the radiocarpal joint what arthrokinematics occur
Ulnar roll and radial glide
70
When do the palmar and intercarpal ligaments become taut
Full extension
71
What is the closed pack position of the radiocarpal joint
Full extension
72
For the intercalated segment what counter rotation occurs during flexion
The scaphoid flexes and the lunate and triquetrium extend
73
What does counter rotation result in
Increased ligamentous tension
74
Is the counter rotation noticeable
No
75
Increasing coaptation of the midcarpal articular surfaces does what
Increases stability
76
For intercalated segment what counter rotation occurs during extension
The scaphoid extends and the lunate and triquetrium flex
77
What are the 2 halves of the midcarpal joint
Ulnar and radial
78
What is the arthrokinematic configuration of the ulnar side of the midcarpal joint
Convex on concave in frontal and sagittal planes
79
What bones are in contact at the ulnar side of the midcarpal joint
Hamate and capitate on lunate and triquetrium
80
What is the arthrokinematic configuration of the radial side of the midcarpal joint
Concave on convex in frontal and sagittal planes
81
What bones are in contact at the radial side of the midcarpal joint
Trapezoid and trapezium on the scaphoid
82
What is the ulnar side of the midcarpal joint linked anatomically and functionally with
Radiocarpal joint
83
Why is the ulnar side of the midcarpal joint linked to the radiocarpal joint
Due to the same convex on concave orientation
84
What are the arthrokinematic motions for flexion and extension at the ulnar side of the metacarpal joint
Flexion: Palmar roll and dorsal glide
Extension: Dorsal roll and palmar glide
85
What is the radial side of the midcarpal joint linked anatomically with
Radiocarpal joint
86
Is the radial side of the midcarpal joint linked functionally with the radiocarpal joint
No
87
What are the arthrokinematic motions for flexion and extension of the radial side of the metacarpal joint
Flexion: Palmar roll and glide
Extension: Dorsal roll and glide
88
During radial deviation which way do the distal row of carpals move
Toward the radial deviation with the proximal row
89
What happens when the ligaments and bones create limitation and approximation during radial deviation
The scaphoid and lunate move palmarly and the trapezoid and trapezium move dorsally
90
What does the motion of the scaphoid, lunate, trapezoid, and trapezium allow for
Full ROM
91
What is the closed pack postion of the radiocarpal and midcarpal joint
Full radial deviation
92
During ulnar deviation which way does the distal row of carpals move
Toward the ulnar deviation with the proximal row of carpals
93
What happens when the ligaments and bones create limitation and approximation during ulnar deviation
The scaphoid and lunate move dorsally and the trapezoid and trapezium move palmarly
94
What does the motion of the scaphoid, lunate, trapezoid, and trapezium allow for
Full ROM
95
What is the closed pack position of the wrist complex
45 wrist extension and slight radial deviation
96
What occurs during extension to the carpals
Rotation toward supination which tightens the ligaments and draws the carpals together
97
What is the open pack position of the wrist complex
Slight flexion with slight ulnar deviation
98
What are the primary wrist flexors (3)
1. Palmaris longus
2. Flexor carpi radialis
3. Flexor carpi ulnaris
99
Which muscle is a better secondary deviator the flexor carpi radialis or flexor carpi ulnaris
Flexor carpi ulnaris
100
Why is the flexor carpi ulnaris a better secondary deviator
Due to the proximal insertion
101
What type of muscle is the flexor carpi ulnaris
Spurt
102
What are the digit flexors with secondary wrist action (3)
1. Flexor digitorum supericialis
2. Flexor digitorum profundas
3. Flexor pollicis longus
103
Which muscle is better able to function as a wrist flexor flexor digitorum superficialis or flexor digitorum profundas
Flexor digitorum superficialis
104
Why is the flexor digitorum superficialis a better wrist flexor
It inserts closer to the wrist
105
What are the primary extensors of the wrist (3)
1. ECRL
2. ECRB
3. ECU
106
Which is more effective at wrist flexion and why, ECRL or ECRB
ECRB due to its central attachment to metacarpal 3
107
What are the digit extensors with secondary wrist action (6)
1. ED
2. EI
3. EDM
4. EPL
5. EPB
6. APL
108
What muscles are injured during dequarvains tenosynovitis (2)
1. APL
| 2. EPB
109
True or False:
Wrist deviation contribution detracts from primary action of the thumb so requires synergistic activity of ECU to offset it
True
110
How do the ECRL/ECRB work synergistically with the ED
If the ECRL/ECRB is weak the ED will help with extension of the wrist
111
How can you tell if the ED is aiding the ECRL/ECRB with wrist extension
Extension of the fingers
112
Where does the ADM originate from
Pisiform
113
How do the FCU and ADM work synergistically
FCU contraction stabilizes pisiform to allow abduction of 5th digit
114
How dot he ECU and EPL/EPB work synergistically during thumb extension
ECU maintains the hand in neutral position
115
What happens to the fingers when you extend the wrist
Finger flexion
116
What happens to the fingers when you flex the wrist
Finger extension
117
What does the corresponding motion at the fingers during wrist motion minimize
Active and passive insufficiency
118
What is tenodesis
Benefits from tightness for function
119
With minimal active wrist extension what happens to the finger flexors
Adaptive shortening
120
For paraplegics increased passive tenison in the fingers allows for what
Increased ADL function
121
How do the FCU and ECU work synergistically (3)
1. Pure ulnar deviation
2. Flexion and ulnar deviation
3. Extension and ulnar deviation
122
When do the FCU and ECU cause pure ulnar deviation
Equal force output of both muscles
123
When do the FCU and ECU cause flexion and ulnar deviation
FCU force greater than ECU
124
When do the FCU and ECU cause extension and ulnar deviation
ECU force greater than FCU
125
How do the FCR and ECR act synergistically
Same as FCU and ECU but to the radial side
126
What type of joint is the CMC 2-4
Plane synovial
127
What is all of the arthrokinematic orientations of the digit joints except the 1st CMC
Concave on convex
128
What type of joint is the 5th CMC
Condyoid/saddle
129
What motions occur at the 5th CMC
Flexion/extension and ABD/ADD
130
What does the 5th CMC being a saddle joint contribute to
Opposition
131
What type of joint is the 1st CMC
Saddle
132
What are the articulating surfaces of the 1st CMC
Trapezium and 1st metacarpal
133
What is the arthrokinematic orientation of the 1st CMC joint in the sagittal plane (ABD/ADD)
Convex on concave
134
What is the arthrokinematic orientation of the 1st CMC joint in the frontal plane (Flex/Ext)
Concave on convex
135
True or False:
| Ligament and capsular laxity allows some rotation and wide ROM at the 1st CMC joint
True
136
What is the amount of flex, ext, and abd at the 1st CMC joint
Flex: 15-20
Ext: 20-30
Abd: 70
137
What plane and axis goes with ABD/ADD of 1st CMC
Sagittal plane M-L axis
138
What plane and axis goer with Flex/Ext of 1st CMC
Frontal plane A-P axis
139
What is the arthrokinematic motion at the CMC 2-5 during flexion and extension
Flexion: Anterior roll and glide
Extension: Posterior roll and glide
140
What is the arthokinematic motion at the 1st CMC during flexion and extension
Extension: Lateral/Radial roll and glide
Flexion: Medial/Ulnar roll and glide
141
What is the arthrokinematic motion at the 1st CMC during ABD and ADD
ABD: Anterior roll posterior glide
ADD: Posterior roll anterior glide
142
What type of joint are the 2-5 MCP joints
Condyloid
143
When are the collateral ligaments and capsule taut for the MCP joints
Flexion
144
What is the close pack position of the MCP 2-5
Flexion
145
True or False:
| ABD/ADD at the 2-5 MCP is difficult while flexed
True
146
What is the open pack of the 2-5 MCP
Neutral to slight flexion
147
What happens to flexion as you go from radial side of the hand to the ulnar side of the hand
Increases from 90 to 110
148
What is extension of the 2-5 MCP active and passive
Active: 30-40
Passive: over 90
149
What is ABD/ADD ROM at 2-5 MCP
30-40
150
When does ABD/ADD increase
With extension
151
What type of joint is the 1st MCP joint
Condyloid
152
What do the 1st CMC and 1st MCP work synergistically to allow
5 degrees of freedom for opposition
153
What type of joint are the PIP and DIP joints
Hinge
154
Does ROM increase or decrease from IP joint 1 to 5
Increase
155
What is flexion at the 1st PIP and DIP
PIP: 100-110
DIP: 80
156
What is flexion at the 5th PIP and DIP
PIP: 135
DIP: 90
157
What is a power grip
Used when there is stability or large forces are required without the need for precision
158
What shape are the objects for power grip
Spherical or cylindrical
159
What is a precision grip
Contour to object and/or some delicate action needed
160
What is a power (key) pinch
Holding object between thumb and lateral border of index finger requires large forces to stabilize object
161
What is a precision pinch
Fine control between index and thumb without power
162
What are the 2 types of pinches
Pulp to pulp and tip to tip
163
What is a hook grip
Doesn't require thumb only partial flexion of PIPs and DIPS static nature grip for long periods of time
164
What is the main muscle for a hook grip
Flexor digitorum profundas
165
What causes swan-neck deformity
RA causing decrease of ligament integrity and increased flexor pull on MCP joint
166
What is the result of swan-neck deformity
MCP flexion, PIP extension, DIP flexion
167
What is the result of boutonniere deformity
MCP extension, PIP flexion, DIP extension
168
Do people with RA usually have ulnar or radial drift
Ulnar drift due to more mobility and looser on ulnar side (path of least resistance)
169
What is the rest position of the hand
```
Wrist extension: 20
Ulnar deviation: 10
MCP flexion: 45
PIP flexion: 30
DIP: slight flexion
```
170
What does the resting position of the hand optimize
Finger flexor force via optimal length tension
171
True or False:
| In the resting hand position all of the wrist muscles are under equal tension
True
172
What is the immobilization position for the hand
Wrist extension: less than 20
MCP flexion: 70
IP joints: neutral
Thumb: CMC wide ABD, MCP slight flexion, and IP neutral
173
Why is the hand immobilized like this
To minimize potential for contractures or adaptive shortening
174
Motivation
Mike Elhers likes little boyz!
