MS: elbow, wrist, hand

Question 1

What is the concave/convex relationship of radius in relation to the ulna

Answer 1

Convex radius proximally, concave radius distally.

Question 2

UCL

Answer 2

triangular;

three parts

Question 3

RCL

Answer 3

fan shaped;

stronger than UCL histologically

Question 4

Annular ligament

Answer 4

attaches to medial ulna, encircles radial head;
protects radial head in semiflexion;
taut at extremes of pronation and supination

Question 5

Quadrate ligament

Answer 5

radial notch (on ulna) to neck of radius;
reinforces inferior joint capsule;
limits spin of supination/pronation

Question 6

Why does the UCL provide better functional stability than RCL

Answer 6

RCL attaches to soft tissue (annular ligament).

UCl requires more strength because functional activities stress medially and compress laterally

Question 7

How does the ulna glide (medially vs laterally) during flexion

Answer 7

laterally

(medial glide occurs during extension)shaped

Question 8

How does the ulna rotate during flexion?

Answer 8

external rotation (supination)

opposite for extension

Question 9

How is the first CMC shaped?

Answer 9

saddle shape, with trapezium being convex M/L and concave A/P

Question 10

Finger concave on convex

Answer 10

Convex proximal aspect, concave distal.

Applies to all joints of fingers

Question 11

Collateral ligaments of the fingers-when are they taut.

Answer 11

All fibers tighten with flexion, volar fibers tighten with extension

Question 12

What does the ulnar nerve innervate in the hand

Answer 12

hypothenar, 5th digit, and medial 4th digit

Question 13

What does the median nerve innervate in the hand

Answer 13

palm thats not innervated by ulnar, dorsal 2nd, 3rd, lateral 4th (from DIP to tip)

Question 14

What does the radial nerve innervate in the hand

Answer 14

dorsal aspects not innervated by ulnar or median