An electric bed, chair and the like includes a back frame, a waist supporting device pivotally connected with the back frame, and an actuator pivotally connected between the back frame and the waist supporting device in such a way that the waist supporting device is turnable by the actuator between a first position and a second position where the waist supporting device protrudes over a top surface of the back frame. The back frame supports a users back and the waist supporting device can optionally support the users waist to make the user feel comfortable when he/she lies or sits down. By controlling the actuator, the service of the waist supporting device can be optimally provided and the elevation protruding over the top surface of the back frame can be adjusted so as to adjust the supporting effect of the waist supporting device.
