A functional knee brace designed to support the posterior cruciate ligament and the femoral-tibial joint in its posterior movement, said brace consisting of two parts (11, 12) joined to each other by articulated mechanisms (13, 14) to be respectively positioned in the femoral and tibial parts of the leg, the lower tibial sector (12) presenting a backward-facing positioning curve (15) with a longer arch in order to be positioned below the calf muscles while the lower part (12) of the knee brace comprises a posterior thrust mechanism (16) which is fixed to the lower arch in such a way as to exert pressure on the calf in a posterior-anterior direction.
