As far as I know reading is the basic sense we need on Bitcoin forum, next is understanding, next is basic knowledge to use computer or gadgets in order to compose lines and answers, if they have this thing then they can just freely be with us, no issues.
Yes these things are most important for disable people and that's why they will completely understand bitcoin and easily join it because bitcoin is the most beneficial currency for them and their life will very easy because bitcoin will provide everything which are important for their family and that's why they can invest their some extra money in bitcoin so their future will more secure because investment will give them huge profit.
I think bitcoin can be a really big help to persons with disabilities, in a sense that it can help them grow by discovering new projects thats suits their health conditions, like XMED it is all about medical industries and medical solutions thats cover the needs of persons with disabilities.