Driving
Contrary to popular belief, RSI affects much more than typing. It disables you to the point that almost any everyday activity can be excruciatingly painful.
I avoid driving whenever possible, because it is one of those activities that causes extreme pain in my arms. I had to drive today, unfortunately.
My right arm was in so much pain that I could not hold on to the steering wheel with it. I don't usually like to drive one-handed, but this time I had no choice. I ended up exiting the highway and resting for awhile, because I was afraid that the pain in my left arm would soon become unbearable.
I think that driving is so painful because it combines the pain of uncomfortable arm movements with the pain of holding the steering wheel tightly. I try to hold the steering wheel loosely, but sometimes I need to hold it tightly for better control.