The auction house Cooper Hewitt offers for sale this unusual piece of furniture. It's called a cockfight chair.
When it was made in the 1720s or 30s in England, reading was becoming increasingly popular for gentlemen. When a man wished to read, he would place a book on the back board, then straddle the chair in a Riker Maneuver. He could place his arms on the rests and keep writing implements on the small shelf.
How did it get the name "cockfight chair"? The Handbook of Antique Chairs explains that "Fops would recline on the chair between bouts and rise, straddling the saddle, to watch the bird-killing sport."