Clinical aspect of palm
1 thenar eminence 2 hypothenar eminence
To test the flexors of the
fingers (flexor digitorum profundus and flexor digitorum superficialis) the
fingers are flexed against resistance etc.
The lumbricals can be
tested by causing flexion at the metacarpophalangeal joints and extension at the interphalangeal
joint- ie the writing position.
The interossei are tested
by asking for adduction or abduction of the fingers against resistance. Remember
that all the muscles of the fingers are supplied by the ulnar nerve except LOAF –
lateral two lumbricals, opponens pollicis brevis, abductor pollicis brevis,
flexor pollicis brevis all of the thenar eminence. To test therefore the function
of the median nerve in the hand m it is important to test the action of the thenar muscles.
The pen touching test
helps to identify the paralysis of the abductor pollicis brevis, a thenar
muscle. The hand is laid on the table and a pen is held a little above the
thumb. With the thumb touching the ground, the subject is asked to raise the
thumb in order to touch the pen. If he cannot do this, it means the abductor
muscle is paralysed and the lesion is probably from the median nerve at the wrist.
The test of the function
of the ulnar nerve at the hand is usually the function of the adductor pollicis
which lies in its own compartment in the hand called the adductor pollicis
compartment. This is performed by the paper handling test. When a newspaper is held
with the thumb upwards, the paralysed thumb does not adduct with the rest of the
fingers since the adductor muscle is paralysed. But a trick action o f the flexor
pollicis longus flexes the thumb and in doing so prominently flexes the
interphalangeal joint of the thumb and its easily recognised as Froment’s sign
Extensor action on the
fingers can be tested by asking the subject to extend the fingers against
Rupture of the tendons of
insertion of the flexors and the extensors can occur. For example rupture of the
collateral slip of the dorsal digital expansion which is inserted into the terminal phalanx, is called baseball or
mallet finger. Rupture of the flexor tendons of the fingers may also arise –e.g. rupture of the flexor digitorum
superficialis. It is commoner to have knife cut of the tendons. Rupture or
division of both tendons cause loss of ability to flex the two interphalangeal
joints while the rupture of only the profundus tendon affects the distal
interphalangeal joint. Rupture of the superficialis alone (not common) only weakenes
the act of flexion since the profundus can perform the action of flexion alone.
Testing the wrist joint
range of movement involves the technique of extension to 70o and flexion to 80o
in the normal range. If pain occurs in this range or if there is inability to make
the range, then the extensors of the carpus (extensor carpi radialis longus and
brevis, and other extensors of the wrist that cross the joint must be sought for. It
also includes the technique of testing for the range of ulnar and radial
deviations performed by the agencies of the extensor carpi radialis and the
flexor carpi radialis (radial deviation) and the extensor carpi ulnaris and the
flexor carpi ulnaris (for ulnar deviation).
digits are supplied by arteries and nerves which run along their medial and
lateral borders. Injections of local anesthetic solution to deaden the nerves must be applied at
the interdigital clefts with needle directed at the lateral and medial aspects of the
digits, most especially but also around the circumference of the digits
generally. This is the same for the lower extremity.
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