Orthopedic braces and artificial limbs for both the upper and lower extremities have been the subject of evaluation programs for many years, and relatively useful methods and techniques have been evolved. The parameters which provide the most useful assessment of these devices are fairly well established. In addition, there exists a body of basic data on normal human locomotion from which useful criteria for evaluating performance can be drawn. A somewhat different situation prevails in an approach to the evaluation of such items as lift aids and wheelchairs since there is available little basic information about their performance factors. Such standards as do exist are descriptive in nature and relate primarily to dimensions and materials of the devices.