Abstract: An adjustable seat occupant assembly for a vehicle seat including an elongate beam spring with an inline slider mechanism at its proximal end that displaces an beam spring flexor, e.g., elongate strap or link, operatively connected to a distal end of the spring to change the amount of flexure and prominence during adjustment to adjust support. In one embodiment, the mechanism is an inline slider crank mechanism carried by a drive carriage extending from the proximal end that rotates a crank when a knob is turned reciprocating the flexor between a fully retracted position where flexure is maximum and a fully extended position flexure is minimum. In another preferred embodiment, the mechanism is an inline slider cam-follower mechanism with a cam rotated by the knob to slidably displace a translating follower yoke that moves the flexor to change spring flexure.