Abstract: An actuator for a manually operated lumbar support system provides for an in-out directional adjustment of a flexible member via control of tension in a cable through rotary motion of a lever or knob attached to a driving shaft associated with a directional one-way locking clutch that slips in either direction under manual actuation and locks when no manual actuation occurs or movement stops. A housing and an eccentric hub combine to form a wedge space. Several locking members, such as rollers or balls, are used to lock the rotation in response to tension from the cable, but only one locking member exists in each wedge space. The designed locking direction may be either clockwise or counterclockwise, as desired. The drive shaft has fingers associated with each locking member to move the locking members to release the clutch in the opposite direction. The tension of the cable may be used to lock the actuator in one direction.