ANN ARBOR---It's a terrifying aspect of old age: Falling.
Nearly one in three people over age 65 and not living in a nursing home fall each year---and those falls often result in serious injury and significant cost.
In a series of studies begun in the early 1990s, James Richardson, M.D., and colleagues at the University of Michigan Health System have documented a strong link between falling and a neurological disorder called peripheral neuropathy.
In Richardson's studies, more than half the subjects with peripheral neuropathy (PN) had suffered a fall, compared with only 10 percent of the subjects without PN. In fact, Richardson has shown that PN affecting the feet and legs makes elderly people about 20 times more likely to fall.
The body collects information about its position from the peripheral nervous system. PN affects that system, however, and causes people to gradually lose sensation in their feet, legs and, to a lesser extent, hands.
Older adults with PN have difficulty sensing the position of their feet and how much their ankles are turned inward or outward. As a result, their center of gravity can easily shift too far without their realizing it---making them unstable. Also, feet and ankle muscles in people with PN develop strength slowly, so they are far less likely to recover when they wobble.
As many as 20 percent of older adults suffer from peripheral neuropathy, which is particularly common in diabetics.
In one study, PN patients could stand on one foot without teetering for only 3.8 seconds. A similar group without PN achieved 32.3 seconds.
That, Richardson says, means doctors can diagnose PN by observing how long a patient can stand on one foot. An ongoing study, in fact, suggests that a patient's ability to stand on one foot is a better indicator of PN than a detailed physical examination.
Preventive steps that can help people avoid PN-related falls include:
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EDITORS: For more detailed information on Dr. Richardson's research, see these peer-reviewed papers:
1) Moderate Peripheral Neuropathy Impairs Weight Transfer and Unipedal Balance in the Elderly, Archives of Physical Medicine and Rehabilitation, November 1996, pp. 1152-1156.
2) Peripheral Nerve Dysfunction and Falls in the Elderly, Postgraduate Medicine, June 1996, pp. 161-172.
3) A Cane Lowers the Risk of Patients with Peripheral Neuropathy Losing Their Balance, Archives of Physical Medicine and Rehabilitation, May 1996, pp. 446-452.
4) Effects of Peripheral Neuropathy on Ankle Inversion and Eversion Detection Thresholds, Archives of Physical Medicine and Rehabilitation, September 1995, pp. 850-856.
5) Peripheral Neuropathy: A True Risk Factor for Falls, Journal of Gerontology: Medical Science, 1995, 50A(4) pp. 211-15.
6) The Relationship Between Electromyographically Documented Peripheral Neuropathy and Falls, Journal of the American Geriatrics Society, October 1992, pp. 1008-1012.
Archives of Physical Medicine and Rehabilitation