Someone who only works in the office at his desk. Usually used to define someone who used to do field work, but due to promotions and age, only sits in a chair and watches others work for him.
Will and I used to inspect bridges together for the state, but ever since he turned 40 and got that promotion, he's nothing but a chair jockey now, barking orders to everyone out working in the field.
A person who out of choice or due to mental disabilities, rocks back and forth in a disturbing manner. These are often laughed at by people of the general public if the jockying is so vigorous the chair collapses or the jockey smashes his/her back against the back of the chair
Hey look, that retard's a complete chair jockey!