Frequently.
My neck, shoulders, elbow, knees , thumb, etc.
The worst is my back. It can go out at the drop of a hat.
One minute I'm fine, and the next I can't lift my coffee cup, or move from my chair.
Then there's my hip. I'll be walking along and then all of a sudden it's like my leg is three inches shorter and isn't even attached to me anymore, and down I go.