12.1 Osteology and Arthrology of the Forearm and Wrist

Question 1

Where are the radial and ulnar styloid processes located? What structures attach to each?

Answer 1

Outermost (i.e. lateral radius and medial ulnar) distal components of each bone

Radial: brachioradialis and radial collateral ligaments of wrist

Ulnar: radioulnar and ulnar collateral ligaments of wrist

Question 2

Origin and insertion of brachioradialis

Answer 2

Origin: lateral supracondylar ridge of humerus

Insertion: radial styloid processes

Question 3

Which bones make up the articular surfaces of the wrist?

Answer 3

Superiorly: distal radius

Inferiorly: carpal bones (scaphoid, lunate, and triquetrum)

Question 4

Which two carpal bones have their own dedicated facets on the distal end of the radius?

Answer 4

• Scaphoid facet
• Lunate facet

Question 5

The joints between carpal bones are called…

Answer 5

Intercarpal joints

Question 6

The joint between the proximal and distal row of carpals is called…

Answer 6

The midcarpal joint

Question 7

The radiocarpal joint is __axial, and ___ in shape.

Answer 7

Biaxial (f/e, ab/ad), and condylar in shape

Question 8

Which structure prevents the ulnar from articulating with the carpal bones?

Answer 8

A fibrocartilaginous/articular disk

Question 9

Which wrist ligaments limit hyperadduction and hyperabduction respectively?

Answer 9

Hyperadduction: lateral collateral ligament

Hyperabduction: medial collateral ligament