Impaired mobility is an important consequence of several common chronic diseases of aging, and is a risk factor for falls, hip fractures, and loss of independence. For a newly developed field study on disability in older persons, an accurate portable instrument is required to measure the walking speed of subjects in their homes. The patient's walking speed is measured at one meter and at either three or four meters. Data obtained from this study will aid in the identification of diseases, since different walking patterns can identify different diseases. Those with Parkinson's disease and certain other problems have a distinctive pattern: They begin walking very slowly, but then attain normal walking speed.
