Some of them are usually pretty well stretched, but some are rather tight. To separate the tight from the loose and focus just on the binding ones, we need the science of kinesiology and of course the Zaichik Stretching Techniques.
You see all the kicks, leg lifts, squats, lunges, turnouts and various other common movement flex the hip and leave the fibers that extend the hip pretty flexible.
However the fibers that flex the hip and thus are stretched in extended hip get tighter and tighter. Once we want to do a skill that requires their flexibility, issues begin.