For the one in eight Americans now over the age of 65, mobility is a vital sign that should be checked regularly, say two health and exercise-science professors at Wake Forest University.

Mobility is closely linked to overall health and quality of life, but health care professionals haven't had an easy and effective way to assess it.

To solve the problem, professors Tony Marsh and Jack Rejeski developed the Mobility Assessment Tool with the help of colleagues in the university's computer science department and at Wake Forest University Baptist Medical Center.

The tool is a way to assess mobility in older adults using video animation rather than written questions. Created for the iPad and the PC, the assessment method takes about four minutes to complete. The score provides information that helps older adults better understand their current mobility and can provide a yardstick to monitor changes in how well they get around.

To take the test, older adults watch short videos of animated figures performing everyday tasks such as climbing stairs or walking while carrying a bag of groceries. The videos help senior citizens picture themselves doing these tasks. They then use the touch screen to indicate what they can and cannot do.

Marsh and Rejeski claim the tool is a quick, simple, and cost-effective way to measure mobility accurately and may help practitioners plan appropriate interventions to remove limitations. They envision the elderly getting what some call activity prescriptions to improve their physical function based on the results of the Mobility Assessment Test. The evaluation easily could be administered in a waiting room before a patient talks to a physician.

The assessment tool offers some advantages over written questionnaires, the professors contend, and can be used when having the older adult physically perform each task isn't practical.

"In pilot testing, we found that the animation technology allowed older adults to project themselves into the tasks," Marsh says. "This removed potential biases that would have occurred if actual people had been filmed doing the tasks."

Using animation instead of actors also made the tool more adaptable and less expensive. In addition, the touch-screen technology dramatically decreases the time it takes to complete the test.

The authors say the animation technology allows for great flexibility in altering the form, speed, and environmental parameters of mobility-related tasks, opening up a wide range of possibilities for future research questions.

"This is a tool that could be used quickly in a physician's office or out in the field," says Rejeski, who has found the assessment tool to be useful in his research on older adults and mobility.

Marsh and Rejeski recently published two studies supporting the video animation tool's effectiveness in measuring mobility.