CanterWave & Quantum: It is not dangerous for the horse for you to sit that far forward in an western saddle (although they were not designed for that so I am not sure what it would do about distributing weight equally like it it supposed to....) but it can be very dangerous for you. The western saddle is designed to keep the rider seated comfortably and securely while the english saddle is designed for close contact with the horse. I have seen more good riders get thrown sitting in a english set in a western saddle than any other time because they are in wrong seat position in a saddle that is not designed for light contact in the seat.

However, getting thrown is not the dangerious part. You have to look at the design of the western saddle with it's high pommel and saddle horn. When you are sitting forward like that if that horse stops, bucks, rears, jumps... anything besides going forward your body is going to be catapulted forward, however unlike in an english saddle or when you are sitting deep in the western saddle (like you are supposed to) where you essentially "role with the punches" your body is going to go forward and be stopped by that high pommel and the saddle horn. Best care scenario is you get a painful bump when your abdomen and lady parts hit that very hard part of the saddle, worse case scenario is some very painful bruises and potential for internal damage. During a reining lesson I leaned to far forward in a sliding stop and instead of being catapulted over the horse's head like I would have been in an english saddle, I hit the saddle horn and believe me, it feels like being punched in the stomach. I was lucky. My trainer told me about an older woman she was watching in a barrel racing competition who landed on the saddle horn and did such severe internal injury that she was forced to have a hysterectomy because of hemorrhaging.

So yes, leaning that far forward in a saddle that was not designed for it IS very dangerous to the rider.

When you are riding properly in a western saddle, you are riding in a balanced seat.