Even healthy people can grow wobbly as they age
I run six or seven miles every morning, and I often follow that workout with a one-mile swim. I lift weights two or three times a week. I take long walks with my dogs every day. But I can’t put on my sweatpants one leg at a time without wobbling.
My balance just isn’t what it used to be.
“Balance declines with age,” says Luigi Ferrucci, a senior investigator and scientific director of the National Institute on Aging. “You can be otherwise perfectly healthy, without any diseases, but still unable to maintain your balance.”
Balance is very important, especially as we get older. People can fall when they lose their balance, sometimes with serious consequences. Every year, more than 1 of 4 older Americans falls, according to the Centers for Disease Control and Prevention, with 2.8 million treated annually in emergency departments for fall injuries. More than 95 per cent of hip fractures result from falls, and falls are the most common cause of traumatic brain injuries.
“Falls due to balance problems are more common in the elderly, and can lead to fractures, especially hip fractures,” says James F. Battey Jr., director of the National Institute on Deafness and Other Communication Disorders. “A woman with osteoporosis who suffers a hip fracture might have to spend several weeks in bed, and her muscles can atrophy — sometimes [she will] never get out of bed again.”
To be sure, while balance generally worsens with age, and can be problematic in the healthiest of elderly individuals, people of any age can suffer from balance disorders. There are more than a dozen such disorders, which can be caused by health conditions, medications or problems in the inner ear or the brain. Symptoms of balance disorders can include dizziness or vertigo, light-headedness, a feeling as if you were going to fall — or actually falling — blurred vision and disorientation.
In 2008, an estimated 14.8 per cent of American adults — 33.4 million people — had a balance problem during the previous year, according to the National Institutes of Health.
Good balance requires input to the brain from three sources: the vestibular system, a complicated structure in the inner ear that processes sensory information about motion and spatial orientation; the muscles, limbs and joints, which tell the brain the position of the body, a process known as proprioception; and vision.
People usually can maintain their balance fairly well if at least two of the three systems are unimpaired.
“If you have perfect proprioception and a perfect vestibular, you can close your eyes and maintain perfect balance,” Ferrucci says. “But if you start having problems in two of the systems, you will have problems maintaining your balance. Two is sufficient, but one is not enough.”
The vestibular system includes the labyrinth, a mazelike structure in the inner ear that is made of bone and soft tissue. Within the labyrinth are semicircular canals containing three fluid-filled ducts. These let the brain know when your head rotates and when it moves up and down.
Inside each canal is a gel-like structure called the cupula, which sits on a cluster of sensory hair cells. When you turn your head, fluid inside the canal moves. This causes the cupula to flex, which bends the hair cells, creating a nerve signal that tells the brain which way your head has turned.
Between the canals and the cochlea (a spiral-shape cavity in the labyrinth) lie two fluid-filled pouches, the utricle and the saccule. These tell your brain the position of your head with respect to gravity — for example, whether you are sitting up or lying down. The utricle and the saccule also have sensory hair cells that alert your brain when you have changed your position.
The vestibular system works with vision and proprioception to control body position. But as we age, cells in the vestibular system begin to die and the fluid inside the canals can deteriorate. We also become prone to conditions that can affect the other two systems — cataracts and osteoarthritis, for example. When this happens, balance can worsen.
“Signals from all three systems — vision, proprioception and the vestibular — all converge on the brain, and when these cells begin to die, the signals get disrupted,” Battey says.
But there are things we can do to make up for these deficiencies and develop what Ferrucci calls “functional reserve.” Aerobic workouts, strength training, stretching and specific exercises aimed at improving balance all are valuable. Also, maintaining normal blood pressure (low blood pressure in particular can cause dizziness upon standing up), preventing ear infections (yes, adults can get them, too) and correcting vision can help, especially in reducing the risk of falls.
As for my pants problem, Ferrucci thinks my vision and proprioception both are working against me. Neither is providing my brain with enough data for decent balance, he says.