Until I started using a fountain pen, I’d always thought that hand cramps were the norm for long writing sessions. Turns out, what I thought was just my heavy handed writing style was probably caused in part by my use of a ballpoint pen. A ballpoint pen relies on gravity to coat the ball with ink. The ball then spins and distributes the ink as the pen is drawn across the paper. Since my preference was always for clear (and dark) writing, I used a great deal of pressure to obtain this result with my stick pen.
My hand cramps disappeared once I started writing with a fountain pen since almost no pressure is necessary for the ink to flow from pen to paper.
Are you heavy handed with your pens?