Design: 10 patients with WC and 10 age- and handedness-matched HV will be videotaped while writing. The WCIS scores will be given to each subject by four blinded raters (Drs. Mark Hallett, Barbara Karp, Katherine Alter, and Camilo Toro) based on the videos. The patients will complete the WCDS. In addition, each individual will be asked to repeat some basic elements of the scale while writing on the screen of a tablet PC, and on the surface of a detached digitizing tablet in order to generate high temporal and spatial resolution pen tip position samples for further numerical analyses and scoring. The biomechanics of the hand will be measured using a published scale.