Hello, PFers! I'm a 3rd Year Mechanical Engineering Undergraduate, just started on a design project titled "Electrically-driven Tricycle for Disabled Children". My team of 3 are currently doing research to make a proposal with valid data before the deadline in the next 4 days. It's pretty much a tricycle fitted with an electric DC motor and an electronic control unit to be used by children with at least a hand to operate. However, we might change the general specification depending on our findings about disabled children and commercialized disabled-friendly tricycles/bicycles. I'm trying to find some statistical data on physically-disabled children/adults to have an idea of what kind of physical disability most people have. For example, how many people were born without 1 hand/1 leg/both hands/both legs/both hands & legs. I've been going through the WHO's website, UNICEF's database, and ChildInfo.org for that information, without ANY results. So I was hoping if anybody knows of some references that I could look into for the statistical data. It doens't matter if most reports/statistics are for adults with physical disabilities, but at least my team has some idea of that demographic group. Help & discussion is greatly appreciated.