A seat assembly includes a seat bottom and a seat back extending along a first axis and coupled to the seat bottom for receiving a vehicle occupant. The seat back includes a seat back frame with at least a first cross-member extending parallel to a second axis, perpendicular to the first axis. The seat assembly further includes a head restraint assembly with a head restraint and at least one head restraint post that supports the head restraint on the seat back. The seat assembly further includes a motor at least partially housed within the first cross-member of the seat back frame and configured to selectively generate an output torque. The seat assembly further includes a drive assembly coupled to the motor and the head restraint assembly to receive the output torque and, in response, translate the head restraint in at least one direction parallel to the first axis.