Abstract: A bed for patients that require periodic movement of their body parts. The bed includes a rectangular frame with panel members transversally disposed. Each panel member is supported by a pair of eccentric members that in turn are rigidly mounted to two spaced apart shaft that are parallel to each other. The shafts are imparted a rotational force by a motor assembly that generates a reciprocating movement that is translated to a rotational movement applied to the shafts. The eccentric members cammingly engage the underside of the panels, and they are divided in two sets of eccentric members that are aligned with respect to each other so that each set is composed on non-adjacent alternate panels that are lifted when the panels of the other set are brought down.