An apparatus for treating a body part of a patient is provided. The apparatus comprises a support for at least partially supporting and holding the body part and a manipulator connected to the support for supporting and maneuvering the support. The manipulator includes a parallel linkage device including a plurality of hingedly interconnected linear actuators. The parallel linkage device includes at least one hinge including a, preferably resilient, tendon joint. Further, a method, a storage medium and a piece of headgear are provided.