Abstract: A knee joint for a leg prosthesis comprising an upper joint part (2) and a lower joint part (3) which can be rotated about a joint axis (5) relative to the upper part of the joint (2), and an upper brake device (14, 15, 20, 21). The brake device comprises a first force transmission element 14, upon which the force triggering the brake effect acts, and which transfers the force at a given transmission ratio to a second force transmission element (15), which, in relation to the joint axis, transfers the displaced force in a substantially parallel direction towards a brake disc (20, 21).