Accurate statistics are not available on the number of individuals with hidden mobility disabilities as this has not been a topic of research focus. We do know that, in the United States, 7.1% of the adult population have serious difficulty walking or climbing stairs (known as an ambulatory disability).

In Canada, Statistics Canada’s 2012 Canadian Survey on Disability found that 19 percent of persons with mobility disabilities walk without mobility aids. The Arthritis Society has documented that 20% of women and 13% of men over the age of 15 have osteoarthritis, a degenerative joint disease that results in difficulty in walking and standing.

In the U.S., the Census Bureau estimates that 9.9 percent of people have trouble walking and 9.2 percent have difficulty with stairs. Of those having difficulty, 3.6 percent do not use wheelchairs or other mobility aids – meaning over 10.6 million Americans have hidden mobility disabilities.

It is hard for people to estimate how far they can walk comfortably so we propose the measure of a standard school bus, which is 35 feet. Informal interviews indicate that most persons with a hidden mobility disability can walk 30-35 feet even when experiencing a moderate level of pain and that 50 feet represents the maximum distance such persons can walk before experiencing severe health consequences.