It is. During the validation studies for alcohol, the parameters were age 65 and more than 50 pounds overweight. That was simply because they didn't have anybody over age 65 and nobody who was more than 50 pounds overweight participating in the validation studies.
With the alcohol workshops that we have done over the years, we've had people who are far older than 65. We've had people who are much heavier than 50 pounds overweight. The tests still work. There will be individuals who can't do them, even though they would fall under what would be the normal parameters, where they're fit, but for whatever reason they can't stand on one leg. When you look at these as being used to elevate suspicion to reasonable and probable grounds, the fact that somebody can't do one test is not a big issue. Overall, the general population can do them. But the mere fact that some individuals may not be able to simply means we'd have to do something else if we believe the person is impaired.