Problems with the inner ear can push some people to their outer limits. To explore how problems in the inner ear can affect balance, especially in older patients, Craig Formby, PhD, a research professor in the Department of Communicative Disorders at the University of Alabama, has developed the Roto-Tilt Chair.

The chair rotates, twirls, and eventually will spin test subjects and patients head over heel so researchers can gather data on how the inner ear contributes to balance and why the system sometimes goes wrong. Specific motions and positions of the chair can be used to test particular parts of the vestibular system, and visual displays can be presented to assess related eye movement disorders.

Dr. Formby, who also has appointments in the College of Engineering and School of Medicine at the university, plans to test the chair and then use it for the benefit of people with balance problems. Neuro Kinetics Inc., of Pittsburgh, PA, built the custom-designed chair to Dr. Formby's specifications. It is installed in the Alabama Innovation and Mentoring of Entrepreneurs (AIME) Building at the university.

Vestibular problems play a role in an estimated half of all fall-related injuries and deaths among senior citizens in the United States. Falls are the leading cause of fatal and nonfatal injuries among older adults, and historical data indicate that at least one-third of Americans age 65 and older will experience a fall this year.

"The enormous societal health care problem and projected future expenses-which are estimated to top $40 billion by 2020-and the fact that most elderly fall injuries and related deaths are preventable have motivated and intensified national efforts toward an all-out attack on elder falls," said Dr. Formby, an investigator funded by the National Institutes of Health (NIH).

He can evaluate a sitting patient by spinning the chair, rapidly tilting it, or combining the spinning and tilting actions to achieve specific motions or positions that activate the inner ear structures. Through chair and eye movements, researchers can monitor a patient's visual and vestibular systems, the two basic sensory systems that control balance. The two systems must work together. The visual system receives input from the eye. Through the intricate workings of the fluid-filled canals and sensory structures within the inner ear, the vestibular system senses changes in head position that are critical for maintaining balance as the eyes focus on an image.

The question is how to pinpoint what is not working properly when dealing with something as complicated as the inner ear with its many mechanisms. "The way the chair is built, the machine can assess all three planes of motion," Dr. Formby said, using the pilot terms of yaw, roll and pitch. "Yaw is rotating movement like that of the spinning office chair, roll is sideways rotation, and pitch sends you head over heels."

He began working on the chair about eight years ago at the University of Maryland School of Medicine. Funding for the machine has come from both NIH and the University of Alabama. He works with colleague Keith Williams, PhD, associate professor of mechanical engineering, and his graduate students to refine and evaluate the capabilities of the new chair.

"It's so powerful and flexible that I will end my career and won't have had enough time to do it justice, so we plan to share its use with outside researchers," Dr. Formby said. "We have already visited NASCAR headquarters in Charlotte, NC, to discuss potential applications of the chair for improving driver safety and the safety of patients who will be tested in the chair."