a system for earthquake retrofit of existing building structures uses a knee brace connected on one end to an existing stud and to an existing floor joist on the other end . an additional stud is provided for reinforcement to prevent the existing stud from failing . the capacity of all other components of the system exceed the capacity of the connections between the knee brace and the existing stud and existing floor joist , which connections act as a fuse in the event of an earthquake and fail first , thus preventing failure of other components and improving collapse capacity of the building structure .