The inability to stand on one leg for 10 seconds in mid-to-later life has been linked to a near doubling in the risk of death, from any cause, within the following 10 years, according to international research.
Conducted among 1702 participants, the study found the proportion of deaths among those who failed the test was significantly higher - 17.5 percent versus 4.5 percent.
After accounting for age, sex and underlying conditions, the inability to stand on one leg was associated with an increased risk of death from any cause within the next decade, rising by a staggering 84 percent, according to the research, which was published in the peer-reviewed medical journal British Journal of Sports Medicine last week.
Based on their findings, the team of international researchers - from the likes of the University of Sydney and Clinimex Clínica de Medicina do Exercício in Brazil - have now suggested this simple and safe test could be included in routine health checks for older adults.
Unlike aerobic fitness, muscle strength and flexibility, balance tends to be reasonably well preserved until the sixth decade of life, when it starts to wane relatively rapidly, the researchers noted.
However, an assessment of balance isn't routinely included in health checks for middle-aged and older men and women, possibly because there isn't any standardised test for it and there is little hard data linking it to clinical outcomes other than falls, they added.
Therefore, the researchers wanted to determine whether a balance test might be a reliable indicator of a person's risk of death from any cause within the next decade and as such, might merit inclusion in routine health checks in later life.
The researchers drew on participants in the Clinimex exercise cohort study, which was established in 1994 to assess the associations between various measures of physical fitness, exercise-related variables and conventional cardiovascular risk factors with ill health and death.
The analysis included 1702 participants aged 51 to 75 at their first check-up, between February 2009 and December 2020. About two-thirds (68 percent) were men.
Weight, waist size and several measures of skinfold thickness - the fold of skin and underlying fat formed by pinching, the thickness of which is a measure of nutritional status - were taken. Details of the participants' medical histories were also provided and only those with stable gait were included.
As part of the check-up, participants were asked to stand on one leg for 10 seconds without any additional support.
To improve the standardisation of the test, participants were asked to place the front of their free foot on the back of the opposite lower leg, while keeping their arms by their sides and their gaze fixed straight ahead. Up to three attempts on either foot were permitted.
In all, about one in five (20.5 percent; 348) participants failed to pass the test. The inability to do so rose in tandem with age, more or less doubling at subsequent five-year intervals from the age of 51 to 55 and onwards.
The proportions of those unable to stand on one leg for 10 seconds were:
- nearly 5 percent among 51 to 55-year-olds
- 8 percent among 56 to 60-year-olds
- just under 18 percent among 61 to 65-year-olds
- and just under 37 percent among 66 to 70-year-olds.
More than half (about 54 percent) of those aged 71 to 75 were unable to complete the test. In other words, people in this age group were more than 11 times as likely to fail as those just 20 years younger.
During an average monitoring period of seven years, 123 (7 percent) people died, 32 percent due to cancer; 30 percent due to cardiovascular disease; 9 percent due to respiratory disease; and 7 percent due to COVID-19 complications. There were no clear temporal trends in the deaths, or differences in the causes, between those who were able to complete the test and those who weren't able to do so, the researchers noted.
But the proportion of deaths among those who failed the test was significantly higher: 17.5 percent compared to 4.5 percent, reflecting an absolute difference of just under 13 percent.
In general, those who failed the test had poorer health: a higher proportion were obese, and/or had heart disease, high blood pressure and unhealthy blood fat profiles. Type 2 diabetes was also three times as common in this group - 38 percent compared to around 13 percent.
After accounting for age, sex and underlying conditions, an inability to stand unsupported on one leg for 10 seconds was associated with an 84 percent heightened risk of death from any cause within the next decade.
As an observational study, the research was unable to establish the cause behind the findings. As the participants were all white Brazilians, the findings might not be more widely applicable to other ethnicities and nations, the researchers acknowledged.
A key limitation of the study was that information on potentially influential factors, including the participants' recent history of falls, physical activity levels, diet, smoking status and use of drugs that may interfere with balance, weren't available.
Regardless, the researchers concluded the 10-second balance test "provides rapid and objective feedback for the patient and health professionals regarding static balance" that adds "useful information regarding mortality risk in middle-aged and older men and women".
