A four-bar-linkage brake-included knee joint includes a knee carriage, first and second links rotatably coupled to the carriage, and a clamp member coupled to a joint body. The clamp member forms a through hole that receives an axle to couple the second links. A compression block is received in a rear portion of the joint body and is set in engagement with a back side of the clamp member. The clamp member forms a gap extending from the through hole of the clamp member to a bottom of the clamp member. When a heel of a prosthesis that includes the knee joint is put on the ground, a reaction force is induced in the prosthesis that causes the compression block to directly depress the clamp member thereby reducing the gap to have the clamp member tightly clamping the axle and thus preventing the axle from further rotation.
