|Contact backrest with permanent and adjustable backrest pressure and seat angle adjustment. The contract backrest, which can be controlled depending on weight, continually adjusts to the current sitting position. It follows the movements of the upper body and hence effectively supports the spine. The backrest can be locked in any position. Due to the variable seat angle of -4° to +10°, the optimum body opening angle of at least 90° can be maintained, depending on the working position. Pressure loads on the thigh are reduced and uniform blood circulation in ensured.