Busted Knee, help!

Anyone help me? I need to find some uncomplicated light exercise that doesn't involve the knees. Suitable for a person with rheumatoid arthritis.

My joint and toe damage in my right foot has put my knee out of whack and affected my hip and my rheumatology physio has told me no exercise, even swimming until I've got something in place via the rheumatology podiatrist.

I'm really going to struggle with MFP without me exercise points. Any ideas?

p.s. I Hate Gyms. And my usual exercise is swimming three times a week and walking every day, with occasional yoga.