The lumbar is the region of the spine Bench Seat Cover between the diaphragm and the pelvis; it supports the most weight and is the most flexible. The adjustable lumbar mechanisms in seats allow the user to nickels the couch following shape in this region, to make it fresh comfortable. Some seats are long enough to support full thigh.

This congenial of seats prevent forward movement of the occupant in case of collision. It is a safety feature, important for front seats over last seats.