The OP mentioned 'parallel' which leads me to believe the arm rest has come loose.
On mine there is a zipper on the bottom rear of each arm rest, this allows the cover to be slipped off. There is a single large bolt that goes into the seat back on which the arm rest pivots. If this bolt has come loose the arm rest will flop around.
Ted 'n' Laurie, plus Jackson (aka Deputy Dog, the Parson Russell Terrier 'fur kid') and, Rylie (who crossed the Rainbow Bridge June 14, 2012).