Your writing practice should never, ever make your hands hurt. Ever. Never.
How can you write without getting the tired old aches they call “writers cramp?”
Everybody is different, so you have to figure that out for yourself. The basic principle is simple: when it hurts, change something so that it doesn’t. You can change the way you sit or how you hold the pen. You can change your expectations for how tidy the words look on the page or for how many words you are able to write. (More suggestions here.)
Before you begin to write, lay your hands comfortably on the table and move them in a way that feels gentle and relaxing. Meditate a little bit on the many different ways a hand can work.
Stay relaxed, pick up a pen, and write about what your hands have already done for you today. Do not let your hand hurt. Not even a little. At the slightest twinge or tiredness, change something until it goes away.
Put the date on the page and give it a title. For extra measure, draw your hand on it.