The present disclosure relates to a vehicle seat assembly. The vehicle seat assembly (1) includes a chassis and a backrest support (5). The backrest support (5) has a first torsion tube (11) for adjusting a recline angle; and the chassis has a second torsion tube (18) for adjusting height rise. The first and second torsion tubes (11, 18) are arranged concentrically about a pivot axis (A). The first and second torsion tubes are rotatable independently of each other about said pivot axis. The first torsion tube is rotatable to adjust the recline angle; and the second torsion tube is rotatable to adjust the rise height. The present disclosure also relates to a vehicle incorporating a vehicle seat assembly.