Hey, let me start by saying that your brother has won a good dedicated brother! I suffer from COPD and exercising was the most hated thing in the world for me. Than a friend suggested me to do a walk in a nice park closed to where I live, and I fell in love with it. So I believe that anyone can do some exercise when they find a place and an activity they like

I would look at chair exercisers first. Soft and gentle exercisers can increase your flexibility