I think, greenlady102, that this was a purely observational test, and didn't establish cause. But given than falls are one of the main causes of death in older people, it makes sense to do what one can to avoid them, I guess.
I found this from Michael Moseley which is a slightly different take:
A good test of your balance is to see how long you can stand on one leg, first with your eyes open and then closed. Take your shoes off, put your hands on your hips and stand on one leg. See how long you last. The test is over as soon as you shift your planted foot or put your raised foot down on the ground. Best of three. Then repeat, with your eyes closed. You will be dismayed by how quickly you start to fall over. Here are the targets that different age groups should be able to manage:
Under 40: 45 seconds with eyes open, 15 seconds with eyes closed.
Aged 40-49: 42 seconds open, 13 seconds closed.
Aged 50-59: 41 seconds open, 8 seconds closed.
Aged 60-69: 32 seconds open, 4 seconds closed.
Aged 70-79: 22 seconds open, 3 seconds closed.