DC's Pity Party
Influenced by the struggles of other groups fighting for Civil Rights, the Disability Rights Movement gathered steam and momentum in the late 1960s and early '70s. During this time, DC made efforts to be socially "with it" and began to feature stories of the Women's and Student Movements as well as African-American characters. It was also during this time that DC published numerous stories with wheelchair-bound characters.
The word "pity" seems to be the signifier of a character in a wheelchair. In the world of DC romance, pity and wheelchairs go hand-in-hand. In these stories, none of the characters are permanently disabled or in a wheelchair due to congenital disorders or childhood illnesses. All are results of recent accidents, are temporary, and are overcome within the course of the story.
I have yet to come across any wheelchair-bound characters in the Marvel or Charlton romance comics, but I am sure they are out there somewhere!