Despite the large personal and economic losses associated with the effects of falling and slipping, the etiology of falling and slipping behavior is unknown. A major inhibition of past research has been the lack of a facility to experimentally investigate such behavior without exposing human subjects to the natural danger of injury resulting from falls. To carry out this research, a facility was constructed to investigate falling and slipping behavior. One component of this facility, a fall arresting robot, is used to experimentally research the basic mechanics involved in falls. Specifically, this robot was designed to provide passive, reactive support of a test subject, so that a reduced friction walk surface could be used to induce a fall. This paper describes the design and development of the fall arresting robot and how the components are combined to provide a functional fall arresting system.