Actually, most reining saddles do have the stirrups placed in the middle. There is also a cut out in the fender under the stirrup attachment to allow the stirrups to swing more. Reining riders are adopting more of a centered dressage type seat. They don't ride with their legs out in front of them. Some of them push their legs forward for the stop and back because that's how they have trained the horse to do the maneuver.