Influence of Eye Movements on Writing Pressure During Handwriting: A CrossSectional Study

Abstract

Writing pressure is the pressure applied to the desk when handwriting). Clinical observation of Occupational therapy showed that when many patients with hemiplegia instructed to control writing pressure during writing exercises, they kept their gaze on the pen tip. Based on this phenomenon, we considered that eye movement during writing in patients with hemiplegia might be involved in controlling writing pressure. So, as basic research, we aimed to investigate whether eye movements are involved in the writing pressure during handwriting by healthy participants. The participants were 28 healthy adults (2 men, 26 women, average age 21.8 ± 0.6 years). The task was to draw 10-cm lines from left to right and 20 times from right-to-left. The instruments used were Tracking Glasses (SMI ETG) and an upper limb Coordination Evaluation system Trace coder (SYSNET Co. Ltd.). Based on eye movement data, the participants were classified into “target locking type,” including those who kept looking at the goal from the start, and “close pursuit type,” including those who kept their eyes on the tip of the pen. In the target locking type, fluctuations in the writing pressure per unit of time value increased greatly when the angular velocity of eye movements changed. In the close pursuit type, fluctuations in the writing pressure per unit of time value were seen at the start of drawing but decreased after that. The results showed that the amount of change in the writing pressure per unit of time value fluctuated greatly in the target locking type and was small in the close pursuit type. These findings suggest that eye movements affect writing pressure during line drawing