I would say 29" I agree with PABowhntr, it will straiten out your upper body. and allow you to bend your arm a touch. If you hunt from a trestand and a deer is under you, it is very hard to bend over and get a shot if your upper body is arched like that. You will tend to creep out of the valley (because it is hard to bend over and stay arched) and the string will want to jump.