The physics of a passenger sitting properly in a chairlift do not require use of a restraining bar. If the chairlift stops suddenly (as from use of the system emergency brake), the carrier's arm connecting to the grip pivots smoothly forward—driven by the chair's inertia—and maintains friction (and seating angle) between the seat and passenger. The restraining bar is useful for children—who do not fit comfortably into adult sized chairs—as well as apprehensive passengers, and for those who are disinclined or unable to sit still. In addition, restraining bars with footrests reduce muscle fatigue from supporting the weight of a snowboard or skis, especially during long lift rides. The restraining bar is also useful in very strong wind and when the chair is coated by ice.