Human Anatomy Vol 1

UPPER LIMB

The movement is assisted by long flexors of the

fingers and thumb (Fig. 10.34), and abductor pollicis

longus.

2 Extension; It takes place mainly at the wrist joint.

The main extensors are;

i. Extensor carpi radialis longus.

ii. Extensor carpi radialis brevis.

iii. Extensor carpi ulnaris.

It is assisted by the extensors of the fingers and

thumb (Fig.10.27).

3 Abduction (radial deaiation): It occurs mainly at the

midcarpal joint. The main abductors are:

i. Flexor carpi radialis.

ii. Extensor carpi radialis longus and extensor

carpi radialis brevis.

iii. Abductor pollicis longus and extensor pollicis

brevis.

4 Adduction (ulnar deaiation): It occurs mainly at the

wrist joint. The main adductors are:

i. Flexor carpi ulnaris.

ii. Extensor carpi ulnaris.

5 Circumduction: The range of flexion is more than

that of extension. Similarly, the range of adduction

is greater than abduction (due to the shorter

styloid process of ulna).

Extensor digiti minimi

Extensor indicis to

join the tendon of

extensor digitorum

Extensor digiti minimi to join the

tendon of extensor digitorum

Figs 10.27a and b: (a) Extensor digitorum, and (b) extensor

digiti minimi

The wrist joint and interphalangeal joints are
commonly involved in rheumatoid arthritis
(Figs 10.28a and b).
The back of the wrist is the common site for a
ganglion. It is a cystic swelling resulting from
mucoid degeneration of synovial sheaths around
the tendons (Fig. 10.29).
The wrist joint can be aspirated from the posterior
surface between the tendons of the extensor pollicis
longus and the extensor digitorum (Fig. 10.30).
The joint is immobilised in optimum position of
30 degrees dorsiflexion (extension).
Because of the complex nature of the joint and the
multiple articulations, any injury to the ligaments
attached to the proximal or the distal row of carpal
bones may cause subluxation of the carpalsverrtrally
or dorsally leading to painful condition of the wrist.
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DISSECIION

Out of these the most important joint with a separate

joint cavity is the first carpometacarpaljoint. This is the

Figs 10.26a and b: Flexors of the wrist