Interactions under the desk: a characterisation of foot movements for input in a seated position

We characterise foot movements as input for seated users. First, we built unconstrained foot pointing performance models in a seated desktop setting using ISO 9241-9-compliant Fitts’s Law tasks. Second, we evaluated the effect of the foot and direction in one-dimensional tasks, finding no effect of the foot used, but a significant effect of the direction in which targets are distributed. Third, we compared one foot against two feet to control two variables, finding that while one foot is better suited for tasks with a spatial representation that matches its movement, there is little difference between the techniques when it does not. Fourth, we analysed the overhead caused by introducing a feet-controlled variable in a mouse task, finding the feet to be comparable to the scroll wheel. Our results show the feet are an effective method of enhancing our interaction with desktop systems and derive a series of design guidelines.