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Analysis of Movement > Elbow and Forearm > Flashcards

Flashcards in Elbow and Forearm Deck (35)
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1
Q

What boney surfaces make up the radiohumeral joint?

A

head of the radius and capitulum of humerus

2
Q

What boney surfaces make up the humeral ulnar joint?

A

trochlea of the humerus, trochlear notch of the ulna

3
Q

What additional motion also occurs in elbow extension?

A

forearm abduction

4
Q

What is gunstock position?

A

gunstock = loss of the normal cubital valgus (13 deg), so arm is almost straight

5
Q

What portion of the UCL in the elbow resists the first stages of valgus?

A

anterior band

6
Q

What ligament blends with the annular ligament?

A

RCL

7
Q

T/F: The UCL has two parts.

A

false, UCL has 3 portions; RCL has 2 portions

8
Q

What does the transverse portion of the UCL do, mainly?

A

stabilizes the elbow joint (the anterior and posterior portions resist more of the valgus force)

9
Q

What ligament is there to prevent damage from falls on an outstretched hand?

A

ulnar portion of lateral collateral ligament; provides posteriolateral tension

10
Q

What are the arthrokinematics of the elbow?

A
flex = anterior roll and slide
extend = posterior roll and slide
11
Q

T/F: The flexors are stretched in elbow flexion.

A

false, they’re compressed

12
Q

What is the functional range for ADLs for elbow flexion/extension?

A

30-130 degrees (instead of 0-145 normally)

13
Q

The interosseous membrane helps distribute what kind of forces? What is it not good at distributing?

A

interosseous membrane

  • good for compressive forces (like falls) at radiocarpal jt
  • bad for distractive forces
14
Q

What do we have more range in, pronation or supination?

A

supination, by 10 degrees (85 vs 75)

15
Q

What ligament supports the proximal radioulnar joint?

A

annular ligament

16
Q

T/F: When we supinate, our GH joint automatically goes into external rotation.

A

true, a little bit of ER

- keep limb close to body when measuring supination so pt. can’t cheat with ER

17
Q

What is the open-pack position for the humeroulnar joint?

A

70 degrees flexion, 10 degrees supination

18
Q

What is the open-pack position for the distal radioulnar joint?

A

10 degrees supination (5 degrees is closed pack)

19
Q

What arthrokinematics occur at the proximal radioulnar joint?

A

just spin, since the annular ligament is so tight

20
Q

What arthrokinematics occur at the distal radioulnar joint?

A

radius moves on ulna (concave on convex)

  • supination = dorsal roll and slide
  • pronation = palmar roll and slide
21
Q

What functional range is needed for ADLs for pronation/supination?

A

50 degrees either way

22
Q

What is the triangular fibrocartilage complex? What’s it do?

A

TFCC = connects ulna to carpal bones, provides stability

  • connects radius and ulna, and radius and carpal bones too
  • consists of capsule, fibrocartilage disk, and ligaments
23
Q

If the interosseus membrane isn’t distributing forces appropriately, what will happen to the joint?

A

decreased joint space, due to degeneration (on medial side?)

24
Q

The certain elbow flexors being utilized are dependent on what?

A

elbow joint position (pronated, supinated, flexed)

25
Q

What muscle is the workhorse of elbow flexion?

A

brachialis

26
Q

What muscle is the workhorse of elbow extension?

A

medial head of tricep (then lateral, then long)

27
Q

At what angle is torque maximized for the bicep?

A

90 degrees elbow flexion

28
Q

What elbow flexor is used in rapid movements for power?

A

brachioradialis

29
Q

What has the shortest moment arm of the elbow flexors? Longest?

A

shortest moment arm = pronator teres

longest moment arm = brachioradialis

30
Q

T/F: Elbow and wrist flexors are both stronger than their opposing extensors.

A

true

31
Q

What muscles help to lock the elbow should there be a C7 or up nerve root lesion?

A

anterior deltoid = horizontal adduction
pec major = adducts arm
• these keep arm close to body and locked for bed mobility since your arm extensors don’t work anymore

32
Q

What is important to prevent in patients that have a C7 or above nerve root lesion?

A

flexion contracture, so they can still use the body-weight elbow lock maneuver to push up out of bed

33
Q

What muscle is the synergist to elbow flexion?

A
  • posterior deltoid -> it makes sure that GH flexion doesn’t occur, so optimal elbow flexion DOES occur
  • exact opposite for elbow extension
34
Q

What’s the best supinator of the forearm? Why?

A

bicep b/c of greater CSA; 2x stronger

35
Q

What’s the best pronator? Why?

A

pronator quadratus because it is exactly perpendicular to axis of motion