Relationship Between Multiple Joint Movements Using Fitts Law

Abstract

Fitts Law predicts the time required to move to an object given the distance to the object’s center and its size. Over the years, Fitts law has been tested on various body parts/joints such as the elbow, wrist, fingers and even tongues. In this paper, we extend Fitts law to model movement by multiple joints. To accomplish this, we first establish a relationship between the performances of different joints, using the concept of atomic movement. We define the atomic movement as the movement of the fastest joint from amongst the joints under consideration. We propose that every other joint movement is a multiple of this atomic movement.