A lower limb function training device for rehabilitation of the lower extremities of a user includes: a single foot rest adapted to receive both feet of the user side by side on an upper surface; a foot rest pivot means for rotation about a pivot axis; a foot rest support structure; and a foot rest drive mechanism arranged to drive the foot rest to rock in a vertical direction about the pivot axis. The lower limb function training device further includes an additional part such as a foot joint data acquisition device which obtains data of a condition of the knee and/or ankle joints of the user.