A gait aid is to be disposed on a shoe, and includes a detecting module, a control circuit and a projecting module. The detecting module generates a sense output based on pressure exerted on a sole of the shoe. The control circuit generates a control signal based at least on the sense output generated by the detecting module. The projecting module is electrically coupled to the control circuit for receiving the control signal therefrom, and is operable, based on the control signal, to project or not to project a cueing mark.
