Median nerve wrist block. Artwork of a syringe being used to inject a local anaesthetic to numb the median nerve, a procedure known as a nerve block. Nerve blocks applied at the wrist allow surgery to be carried out on the hand. Below the wrist, this nerve provides sensation for two-thirds of the palm, from the thumb to the index and middle fingers, half the ring finger, and distal dorsal surfaces of those fingers (see C016/6836 and C016/6837). This injection is applied between the flexor carpi radialis and palmaris longus tendons. For all three injections for a complete hand nerve block, see C016/6827 to C016/6829.