Any repetitive movement or activity can cause injury or strain in your hands, including hand or finger cramps from writing, according to the Dystonia Society, an organization that studies chronic muscle spasm. Hand cramps are often given the name writer's cramp or musician's cramp, reflecting the nature of the overuse.
The Dystonia Society suggests that the primary causes of writer's cramp include hand tension and unusual positioning of the arm and elbow during long writing sessions. Musician's cramp, similarly, may cause the fingers to curl in spasm. Both afflictions are usually temporary. If any repetitive or prolonged activity is causing pain, it is advised to cease the activity.