Wrist Flashcards

1
Q

Allows the wrist and hand to rotate on the radius farther into ulnar deviation than into radial deviation

A

Ulnar tilt

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2
Q

What is the normal degree for ulnar tilt?

A

25 degrees

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3
Q

The distal articular surface of the radius is angered about ___ degrees in the palmar direction. This _______ accounts, in part, for greater amounts of flexion than extension in the wrist

A

10; palmar

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4
Q

Which row of carpal bones is relatively loose? which row is bound tightly by strong ligaments?

A

proximal; distal (creates a stable base for metacarpal bones)

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5
Q

Arches over the concave carpal bones to form tunnel

A

Transverse carpal ligament

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6
Q

What is contained in the carpal tunnel?

A
  • median nerve
  • 4 tendons of flexor digitorum superficialis
  • 4 tendons of flexor digitorum profundus
  • tendon of pollicis longus
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7
Q

What prevents contained ligaments from bowstringing anteriorly and out of the carpal tunnel during grasping actions performed with a partially flexed wrist?

A

transverse carpal ligament

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8
Q

Where is the axis of rotation in the wrist?

A

Head of capitate (firmly articulated with 3rd metacarpal)

- for both medial-lateral and anterior-posterior

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9
Q

What is the ROM for wrist flexion? extension?

A

70-85
60-75
- flexion normally exceeds extension by 10-15 degrees

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10
Q

Why does flexion normally exceed extension?

A

Palmar tilt of radius

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11
Q

What is the ROM for ulnar deviation? Radial deviation?

A

35-40
15-20
- ulnar deviation usually 2x more than radial deviation due to ulnar tilt of radius

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12
Q

What is the average wrist ROM needed for ADL’s?

A

40 degrees flexion
40 degrees extension
10 degrees radial deviation
30 degrees ulnar deviation

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13
Q

What is the “position of function” of the wrist (the average position of the wrist during daily activities)?

A

10-25 degrees extension

10 degrees ulnar deviation

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14
Q

The “position of function” is the position the wrist would be fused or splinted. Why would you fuse the wrist or any joint?

A

stability and relief of pain

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15
Q

What is the capsular pattern for the radiocarpal joint?

A

Equal amounts of flexion and extension

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16
Q

What is the close packed position for the radiocarpal joint? open pack?

A

Extension, radial deviation;

neutral, slight ulnar deviation

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17
Q

Arthrology of the radiocarpal joint: [concave/convex] radius and disc on [concave/convex] scaphoid and lunate

A

Concave; convex

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18
Q

__% of total force passes through the scaphoid and lunate to the radius
__% of force passes through the articular disc

A

80%; 20%

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19
Q

Where is the mid carpal joint?

A

Between proximal and distal rows of carpal bones

20
Q

The wrist is a double-joint system and motion occurs simultaneously at both radiocarpal and mid carpal joints. Where does the majority of wrist flexion occur? wrist extension?

A

Midcarpal joint; radiocarpal joint

21
Q

Formed by the distal radius, lunate, capitate, and 3rd metacarpal

A

central column of wrist

22
Q

in wrist extension, the ____ ligaments becomes slackened and the ____ ligaments become taut

A

dorsal radiocarpal; palmar radiocarpal

23
Q

Extension occurs as the convex surface of the lunate rolls ___ on the radius and simultaneously slides ____. At the mid carpal joint, the head of the capitate rolls ___ on the lunate and simultaneously slides in a ____ direction

A

dorsally; palmarly; dorsally; palmarly

24
Q

Ulnar deviation (for both the mid carpal and radiocarpal joint) involves the scaphoid, lunate, and triquetrum rolling _____ and slide a significant distance ____.

A

Ulnarly; radially

  • both joints contribute to fairly equal overall wrist motion
25
Q

The amount of radial deviation at the _____ joint is limited as the radial slide of the carpus impinges agains the styloid process of the radius. Therefore, the majority of radial deviation occurs at the _____ joint.

A

radiocarpal; mid carpal

26
Q

During radial deviation, the proximal row of carpal bones ____ 20 degrees. During ulnar deviation, the proximal row of carpal bones ____ 20 degrees.

A

Flexes; extends

27
Q

What is the primary cause of carpal instability? what are the two common types?

A

Laxity or rupture of ligaments

  1. Rotation collapse of wrist (zig zag deformity; DISI or VISI)
  2. Ulnar translocation of carpus
28
Q

How can you tell if a rotational collapse of the wrist is a DISI or a VISI?

A

The direction the distal end of the lunate faces

29
Q

What does the ulnar tilt of the radius create?

A

a translation force in the ulnar direction

30
Q

What is an excessive ulnar translocation of the carpus result in?

A

altered biomechanics of the wrist and hand; radial side = stretched ligaments; ulnar side = compressed ligaments

31
Q

What are the primary wrist extensors?

A
  1. Extensor carpi radialis longus
  2. Extensor carpi radialis brevis
  3. Extensor carpi ulnaris
32
Q

Prevents the tendons from “bowstringing” up and away from the radiocarpal joint during active extension

A

Extensor retinaculum

33
Q

Compartment I (containing tendons of extensor pollicis previous and abductor pollicis longus) are particularly susceptible to inflammation, a condition called

A

de Quervain’s tenosynovitis

34
Q

If you have a radial nerve disruption in the upper arm, what wrist deformity could it cause?

A

DISI

35
Q

What is the main function of the wrist extensors?

A

to position and stabilize the wrist during activities involving active flexion of the fingers

36
Q

The wrist extensor muscles must counterbalance the significant ___________ torque produced by the [extrinsic] finger flexor muscles

A

wrist flexion

37
Q

What position must the wrist be in to produce maximal grip force? why?

A

30 degrees wrist extension

  • optimizes the length-tension relationship [active insufficiency)
  • overstretched finger extensors create a passive extensor torque at the fingers
38
Q

Finger flexion needs a counterbalance of wrist extension. Activities that require repetitive forceful grasp, such as hammering or playing tennis, may stress the proximal attachment site of the wrist extensor muscles, often leading to a painful condition. What is this condition called?

A

Lateral epicondylitis/ epicondylagia

  • AKA tennis elbow
  • may not be inflammatory but rather degenerative
39
Q

What are the primary wrist flexors?

A
  1. Flexor carpi radialis
  2. Flexor carpi ulnaris
  3. Palmaris longus
40
Q

Which muscle produces the greatest wrist flexion toque potential of the three primary wrist flexors?

A

flexor carpi ulnaris

41
Q

Do wrist flexors or wrist extensors have a larger cross0sectional area?

A

flexors (2x)

42
Q

wrist flexor muscles produce about __% greater isometric torque than the wrist extensor muscles

A

70

43
Q

distal radius fracture; growth plate fracture that causes ulnar tilt to be significantly less

A

Cole’s fx

44
Q

What action could cause a scaphoid fracture?

A

Punching a wall

- scaphoid provides stability for lunate

45
Q

Synovial fluid buildup in sheath or joint; pin in dorsal of the wrist

A

ganglion cysts