<P> This nerve can cause an electric shock - like sensation by striking the medial epicondyle of the humerus from posteriorly , or inferiorly with the elbow flexed . The ulnar nerve is trapped between the bone and the overlying skin at this point . This is commonly referred to as bumping one 's `` funny bone '' . This name is thought to be a pun , based on the sound resemblance between the name of the bone of the upper arm , the `` humerus '' and the word `` humorous '' . Alternatively , according to the Oxford English Dictionary it may refer to `` the peculiar sensation experienced when it is struck '' . </P>
striking the funny bone is actually compression of the
ulnar nerve