Originates at the back of the knee (front leg) and the back of the top part of the cannon bone (hind leg), attaching to the sesamoid bones. The lower portion of the ligament attaches the lower part of the sesamoid bones to the pastern bones. Its function is to support the fetlock. The lower ligaments that attaches the sesamoid bone to the pastern bones are the distal sesamoidean ligaments.