A wheeled carriage for supporting a patient includes a patient support with head and foot ends and a wheeled base supported by castered wheels. Auxiliary wheels secured to an auxiliary wheel support structure are suspendedly mounted to the wheeled base. A control apparatus includes manipulative members, such as foot pedals at the head and foot ends and at the lateral sides of the wheeled carriage. The side foot pedals are supported by a transverse control shaft. The transverse control shaft extends through apertures in the auxiliary wheel support structure. Wheel bearing devices rotatably attach the auxiliary wheels relative to the transverse control shaft. A linkage arrangement enables the side foot pedals to physically move with the auxiliary wheels during movement between deployed and stowed positions.