Standing up straight and keeping your body centered may seem like second nature to most of us. But for people with balance disorders, it is anything but easy. Wobbly and unsure on their feet, they often have difficulty walking and are prone to falls, a leading cause of injury and death in the elderly.
Certain diseases and medications, or the normal wear and tear of aging, can weaken the sensory signals transmitted to the part of the brain that governs gravitational stability, which is why people become unsteady, dizzy or disoriented.
Now scientists have developed a novel balance feedback device that weighs less than a pound and can be worn on a belt like a pager. It may help correct balance difficulties by providing sufferers with the sensory data they are missing.
"Balance disorders can be terribly social-stigmatizing because people think they're drunk, and some people withdraw from daily activities because they're afraid of falling," says Christopher Platt, program director for balance and vestibular sciences for the National Institute on Deafness and Other Communication Disorders in Bethesda, Md. "A device that accelerates someone's ability to retrain themselves holds a lot of promise."
An estimated 20% of Americans suffer from balance disorders. These difficulties can be triggered by viral infections, head injuries, aging, illnesses such as multiple sclerosis and Parkinson's disease, or inner ear damage, which can be caused by Meniere's disease, poor blood circulation or some antibiotics.
Although maintaining balance may seem effortless, keeping your body stable is a gravity-defying skill that requires input from three main senses, says Fay Horak, a neuroscientist who helped develop the new technology at the Oregon Health and Science University in Beaverton. The brain integrates information from our vision, from the vestibular (balance) system in the inner ear and from the somatosensory system -- the sense receptors in our muscles, joints, skin and feet -- that tells us where our body is in reference to surfaces that we contact.
Most people sway slightly when they're standing still. "You think you are totally frozen, but your body is making little movements that your brain controls to maintain your balance," says Marco Dozza, a biomedical engineer at the University of Bologna in Italy, who is part of the OHSU research team.
