Progress in the gait lab.
Text: Christoph Dieffenbacher
Discrete irregularities in gait can point to cognitive deficits later in life – even years in advance. The University Center for Medicine of Aging at the Felix Platter Hospital in Basel is involved in cutting-edge research in this area.
There’s more to this walkway than meets the eye. Looking at the ten-meter strip of plastic, you wouldn’t think that some 30,000 tiny sensors were stuck to the bottom. The walkway, which is used to objectively measure gait at the Basel Mobility Center, is housed in a former dining hall on the grounds of the Felix Platter Hospital. When someone walks across it, the imbedded pressure sensors can measure up to 80 different parameters – from the walking speed to the length and width of the strides and even tiny irregularities that are undetectable with the naked eye.
Over the last eleven years, more than 6,000 gait analyses have been performed using this GAITRite walkway. The data comes mainly from older individuals who were referred by their family doctor and who find walking increasingly difficult. Whether it be due to dizziness, memory problems, lack of muscle mass or joint pain, something they used to take for granted becomes a serious problem: unsteady gait in old age can lead to life-threatening falls.
Usually, patients have to complete five or six lengths of the carpet walkway. Sometimes, they are asked to walk faster or slower than normal; sometimes, they must walk while simultaneously performing a second task, such as counting backwards or naming different animals. These “dual task” tests place an additional burden on the brain – that is, the subjects have to complete an additional cognitive task while they walk. This is one of the research specialties of the gait lab at the Basel Mobility Center, which is affiliated to the Felix Platter Hospital and the Department of Clinical Geriatrics at the University of Basel. “When people are burdened with an additional task while walking, their speed generally slows by a tenth,” says Dr. Stephanie A. Bridenbaugh, who is head of the lab. “They also walk with a more irregular gait and often with a slightly wider stride.”
What is the norm?
In addition to diagnosis and early detection, the doctor spends half of her time on research, which she conducts in collaboration with colleagues in Switzerland and abroad. She explains that unsteady gait can often be a symptom of underlying problems. Her current research seeks to determine what actually constitutes a normal gait in old age. In terms of speed, for example, the norm for adults is at least 100 centimeters per second, but she says that many aspects remain unclear. For example, what is the normal walking speed of an 80-year-old woman?
For Bridenbaugh, geriatrics is “one of the most exciting areas” of medicine, because it spans multiple disciplines: “Here, there’s no such thing as a textbook case.” She cites the problems her older patients experience in everyday life: While out in public, they are confronted with dozens of different stimuli – on crosswalks, on escalators or on the tram. Without realizing it, older people often automatically stop walking in these situations and are then pushed from behind, barged into or bombarded with insults. “It’d be nice if more people put themselves in older people’s shoes,” the doctor says.
Detecting dementia in advance
Not uncommonly, the cause of certain gait disorders can be found in the brain, and specifically in the area responsible for sensory and cognitive functions, says Bridenbaugh: “Researchers in the US have shown that cognitive deficits can be predicted based on walking speed up to ten years in advance.” Gait analysis can even be used to estimate the risk of eventually developing some form of dementia, such as Alzheimer’s disease.
Researchers in Basel are also collecting data and carrying out studies in this area. For example, they are investigating whether it is possible to predict the type of dementia a person will develop later in life based on gait disorders. They are also studying the influence of diet and muscular atrophy on gait. In addition, studies have found that ginkgo preparations can help people with mild cognitive impairment improve their gait, as the plant extract improves blood circulation in the brain. Another finding to emerge from Basel is that older people who still have their own teeth are steadier on their feet than people with missing teeth or dentures.
Meditation and mobility
“Sometimes, the gait measurements lead us to new, previously unknown findings,” says the doctor. Her goal is to help patients improve their gait using simple methods. In this regard, research and clinical practice can benefit from one another: The latest findings and advances in geriatric medicine can be implemented directly. For example, a study is currently underway into the relationship between Eastern forms of movement and mobility in old age.
In operation all week long, the gait lab in Basel is used to its full capacity. Indeed, Bridenbaugh is already looking forward to the relocation to a new building next year, where there are plans for two gait labs so that researchers can take even more extensive measurements. Using small, wearable sensors, it is possible to measure other parameters such as upper body sway or stepping height, for example. Bridenbaugh hopes to continue gathering important insights to create a comprehensive picture of gait that can be presented in the form of objective figures, and compared with other values.
Twice as many over-70s by 2040
The American-born doctor’s remarks point to a future that is dominated by aging research and preventive healthcare: “If the number of over-70s actually doubles by 2040, we will face real challenges as a society.” That includes challenges at the economic level, says Bridenbaugh: “If we manage to delay placement of older people into a retirement or nursing home by just one year, we could save millions or even billions of francs.”
Stephanie A. Bridenbaugh is head of the gait lab at the Basel Mobility Center, affiliated to the Felix Platter Hospital in Basel and the clinical chair of geriatrics at the University of Basel.
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