Gather all the fingers of one hand together, and tense your wrist. If the tendon on the inner side of the wrist doesn’t become visible, you must be one of the 14% of people who don’t have the long palmar muscle. This muscle belongs to the vestigial parts of the body — those whose necessity has disappeared in the course of evolution. Experts say that the absence of the long palmar muscle does not affect the grip strength or any other functions assigned to the hands.