The invention relates to a passive orthopedic aid in the form of a foot prosthesis or foot orthosis, with a first part which is connected to a second part in a rotatable manner via a swivel joint, with a sensor arrangement for measuring parameters that provide indications of instantaneous operation requirements of the aid, with a control means which is connected to the control arrangement and is used to determine operation requirements and to generate corresponding control signals, with a controllable hydraulic damping arrangement with which a movement resistance acting on the rotation movement between the first part and the second part can be modified, and with a control means which converts the control signals of the processor arrangement and is used to control the damping arrangement.
