Human Anatomy Vol 1

UPPER LIMB

Pronator quadratus

Supinator

Fig. 10.21 : Pronators of the forearm

Biceps brachii

Humerus

(a) (b)

Figs 10.23a and b: (a) Supination, and (b) pronation

Type

Wrist joint is a synovial joint of the ellipsoid variety

between lower end of radius dnd articular disc of

inferior radioulnar joint proximally and three lateral

bones of proximal row of carPus, i.e. scaphoid, lunate

and triquetral distally.

The pisiform does not play a role in the radiocarpal

articulation. It is a sesamoid bone acting as a pulley for

flexor carpi ulnaris.

Adiculor Surfoces

er

1 Inferior surface of the lower end of the radius

(see Fi9.2.24).

2 Articular disc of the inferior radioulnar joint

(Fig.10.2a).

[oI

1 Scaphoid

2 Lunate

3 Triquetral bones.

Ligomenls

L The articular capsule surrounds the joint. It is attached

above to the lower ends of the radius and ulna, and

s. A protru-

prestyloid

of the ulna

and in front of the articular disc. It is bounded

inferiorly by a small meniscus projecting inwards

Pronator teres

tt
E

()

IL

e

=
c
.e
()
o)
o Fig.10.22: Supinators of the forearm