Your body is constantly trying to maintain holistic HOMEOSTASIS. When you have too much mobility in one area, your body tries to compensate by increasing stability in another area. And vice versa. When you have too much stability, from tight muscles to arthritic joints, your body compensates by becoming too loose or mobile in other areas.
In order to prevent long term problems caused by these compensations, you should get checked regularly. Keeping your body balanced — by increasing movement in your spine and your joints that are too stable AND by decreasing movement where you have too much mobility — prevents chronic structural problems and promotes optimal holistic health.