The present invention provides a stabilizing device that helps to prevent over-pronation or over-supination and a shoe which includes such a stabilizing device. The stabilizing device is provided along a side of the midsole and preferably extends laterally between about 20% and about 35% of a width of the sole towards the opposite side thereof. The stabilizing device includes an elongated portion and a sidewall portion that extends transversely from the elongated portion. The sidewall portion forms part of an outer peripheral wall of the shoe. The sidewall portion has a stiffness which varies along the length of the stabilizing device to provide a predetermined support profile along the side of the sole. The elongated portion can also vary in stiffness along its length. The stabilizing device can be formed of a resilient material using an injection molding procedure or similar technique.
