A belt lumbar for a vehicle seat has a pair of brackets that are respectively located at opposite ends of the belt, a platform that extends between the brackets, and hinges that connect the platform to the brackets. A bowden cable extends between and pulls the brackets toward each other from a first position to a second position. The hinges are living hinges which have more flexibility than the pair of brackets and the platform. In response to the brackets moving toward each other, the hinges rotate relative to the platform and the brackets and extend the platform away from the brackets. Springs connect the ends of the belt to the sides of the seat frame.