Nerve stimulation will be used with a current of 0,2 mA (milli Amps). Following completion of the block the dermatome supplied by the MACN will be tested by loss of cold sensation. After 20 minutes the dermatomes and motor function of all nerves are tested by elbow flexion and extension, primarily thumb opposition and abduction of the index finger. Sensory block is tested at the fifth finger (ulnar nerve, the hand palm at the thumb (medial nerve)and the dorsum of the hand ( radial nerve), the lateral (musculocutaneous nerve) and medial skin ( MACN) of the forearm.