Here is a Monday Methods discussion of how historians investigate "disability" in the past.

Although retrodiagnosis (especially of psychological disorders) is fun, tempting, and a very popular subject for freshman English students, historians treat disability historically. We consider disability to consist of two parts: physical or intellectual impairment on one hand, and how social conditions turn that impairment into disability: an inability to participate fully in contemporary society.

Without a doubt, the most popular discussion of history disability on AskHistorians relates to PTSD in premodern soldiers--it's at the top of our Military History FAQ.

Current: "Disability"

On deck: "14th Century AD"

In the Hole: "Resistance and Conformity"