A support assembly having a first support region with adjustable degree of support and a second support region with adjustable degree of support includes a support member for incorporation into a seat frame, a first adjustment arrangement for adjusting the degree of support in the first support region, and a second adjustment arrangement for adjusting the degree of support in the second support region. An actuator is coupled to the first adjustment arrangement and to the second adjustment arrangement. The actuator is configured to simultaneously act on the first and second adjustment arrangements in opposite directions. A wire-length control mechanism is coupled to one of the first adjustment arrangement and the second adjustment arrangement and is configured to absorb an excessive length of a wire of the one of the first adjustment arrangement and the second adjustment arrangement.