But wasn't Legolas facing forward, away from the horse, at the start of his maneuvre. I don't know whether, objectively, the maneuvre is possible or not, but the way that it is portrayed in the film, it does look physically impossible to me. Having studied it once or twice since the issue was first raised, it looks to me like his arm would have to pass through his body. But then again, I'm no expert in Elven horseman(elf?)ship.