An unsteady gait is an abnormality in walking that can be caused by diseases of or damage to the legs and feet (including the bones, joints, blood vessels, muscles, and other soft tissues) or to the nervous system that controls the movements necessary for walking.n unsteady gait may occur as a result of a temporary condition, such as an injury or infection, or it may indicate a long-term (chronic) problem. An unsteady gait can be mild enough to be barely noticeable or may be so severe as to cause an inability to perform tasks of daily living.