A Single Clinical Sign To Test For Functioning Of All 3 Nerves Of The Hand
S Rajkumar, S Tay
Keywords
function, nerves of hand, single test
Citation
S Rajkumar, S Tay. A Single Clinical Sign To Test For Functioning Of All 3 Nerves Of The Hand. The Internet Journal of Orthopedic Surgery. 2005 Volume 3 Number 1.
Abstract
There are various signs and tests used in routine practice when examining nerve function of the hand. There are specific tests for detecting nerve weakness
3 Nerve test - (Kumar Test)
Ask the patient to dorsiflex his/her wrist,
Abduct the fingers of 3 rd , 4th and 5 th fingers and
Make a ring (O) sign with thumb and index finger tips touching each other (Figure 1). This single test will assess motor power of all three nerves.
Figure 1
Inability to dorsiflex wrist indicates Radial nerve weakness (wrist dorsiflexors 1 ); inability to abduct the ulnar half of fingers indicates Ulnar nerve weakness (Dorsal Interossei 1 ) and inability to appose thumb and index finger tips to make an O sign indicates Median nerve weakness (Flexor Pollicus Longus and Flexor Digitorium Profundus of index finger 1 ).
This test can be effectively performed in a clinical setting to rapidly test for nerve weakness although the sensory component cannot be assessed at the same time. If a nerve weakness is detected, then further tests can be carried out to confirm it.
This test is a useful test to rapidly diagnose nerve injuries in casualty and clinical setting.