The invention relates to a control unit (57) for a wearable sitting posture assisting device (10), having at least one operation program, which is designed to control a blocking means (17) of at least one leg unit (12, 12) of the wearable sitting posture assisting device (10) in dependence of a sensor signal representing a sitting angle (21) between an upper support (13) and a lower support (14) of the at least one leg unit (12, 12)" to a wearable sitting posture assisting device with such a control unit (57) and a method for controlling a wearable sitting posture assisting device (10).
