The invention relates to a supporting device for a support (12) used to support a lower extremity, in particular a knee joint, a lower leg, a foot or an ankle, an upper leg support (14) and a lower leg support (16) being provided and interconnected via an articulation (17), the upper leg support (14) comprises at least a load-bearing surface (24, 28), the lower leg support (16) comprises at least a load-bearing surface (31), a support fixing (18) is provided, which engages with the support (12), the lower leg support (16) and the support fixing (18) being coupled to one another for the transfer of force. (See FIG. 1)