Presented is a manner of organizing and grouping performance information to support the design and development of physical movement aids for non-ambulatory persons which enable them to ambulate or at least change their position in a semiambulatory fashion. Hierarchical levels of psychobiologic deficiency and corresponding condition variables are given for the various physically handicapping conditions which result in non-ambulation. Information on performance characteristics is intended to be used in design research for determining abilities and needs of specific non-ambulatory groups at all levels of non-ambulation and for determining the characteristics which the proposed dynamic artificial aids must possess. A case study using the data provided is included to illustrate that a psychobiologic approach to design is possible and to indicate the type of reasoning which needs to be followed in developing design solutions. (KW)