Abstract: Disclosed herein is a power headrest apparatus capable of automatically adjusting vertical and forward-backward movement of a headrest using motors, and of sufficiently securing an amount of forward-backward movement of the headrest using a pair of link members, which are arranged to intersect with each other in an X form, while a width of the headrest in forward and backward directions thereof is maintained below a certain level.

Abstract: Disclosed herein is a 4-way lumbar support capable of automatically adjusting a vertical curved position and an amount of curvature of a lumbar plate, while securely supporting the lumbar plate even when a large load, such as the rear-end collision of a vehicle, is applied to the lumbar plate. In addition, the 4-way lumbar support can adjust an amount of forward curvature of the lumbar plate using a pusher including a pair of hinge members, thereby enabling the amount of forward curvature of the lumbar plate to be adjusted across a wider range without increasing the thickness of a seat back in the forward and backward directions thereof.