RETED

Although several databases of handwriting movements have been created so, none of them has been specifically designed for studying the effect of age during ellipse drawing. Ninety subjects voluntarily participated in the database construction. Their age ranged from 19 to 85 years: 30 participants in the range [19, 39] years, 30 in the range [40, 59] and 30 subjects in the range [60, 85]. Twenty-six women (range 19-72 years) and sixty-four men (range 25-85 years) participated. The oldest subjects have been recruited in retirement homes in the towns of Tunis, Sfax, and Gafsa in Tunisia. The participants’ health status was checked based on their self-report and on the indications of the retirement homes staff. The non-inclusion criteria were any neurodegenerative or musculoskeletal pathology that could affect the understanding of the instructions and the ability to draw. In addition, each participant was asked to self evaluate her(his) level of writing activity between frequent, occasional or rare. The participants had normal or corrected to normal vision.

During data acquisition, participants were seated in a comfortable chair with a seat height of 45 cm and a backrest while keeping their elbow in contact with a table 80 cm high. The height of the chair and the table were not adjustable.  The participants were asked to perform a repetitive tracing of an ellipse on a graphical tablet (GENIUS graphic tablet MousePen i608X) with a stylus (KYE Systems Europe GmbH, Langenfeld, Germany) for 60 seconds. The graphical tablet was positioned horizontally on the table. The model of the ellipse was drawn on a sheet of paper placed on top of the tablet. The experimenter verified that the participants were correctly seated and felt comfortable drawing on the graphical tablet. In addition, and in order to ensure that the participants had well understood the requested movement, the experimenter displayed the task with the stylus. The participants were allowed to practice the task before data recording for three minutes. The experimenter verified that the participants posture was correct and that the instructions were well understood. The participants were asked to execute the movement at their preferred speed and no instruction on movement velocity was given. A custom-made software developed in MATLAB (MathWorks, Natick MA, USA) was used to record the data.

The characteristics of the ellipse were: Long axis = 60mm, small axis = 36mm, inclination of the major axis θ = 30 °