I don't have arthritis but have had heel spurs and plantar faciaitis in both feet so I understand your pain.
Lots of soft floor mats in front of my machine and a chair so I can sit whenever possible.
My friend has arthritis in both hands and the only thing that keeps him going is playing his guitar. That and the $1000/month medication.
I hope that when I am 65 I am as productive as you.
Mike