What are the minimum requirements to join a Pilates class?

As long as your doctor has released you to exercise you will be fine to join a basic pilates class. The instructor should be trained to work with people of all fitness levels. The best thing to do is look up videos of beginning pilates classes to be able to visualize what the basic classes do. I am sure if your doctor says you can...you will be able to do the basic. Don't be intimidated!