Is it ever OK for non-disabled actors to play disabled roles?

Bryan Cranston’s defence of playing a wheelchair user only strengthens a cycle that shuts out disabled actorsBryan Cranston’s defence of playing a wheelchair user in the new comedy-drama The Upside has underlined a particular point in the complicated issue of equality and diversity in acting: should non-disabled actors play disabled roles?We are familiar with the repellent days of “blacking up” – the disabled actors’ equivalent is “cripping up”, a