Functional analysis of finger contact locations during grasping

In this paper we present a method for studying human selection of fingertip contact point locations during grasping and manipulation. Our aim is to perform a functional analysis, looking at how a particular choice of contact point distribution affects the subjects´ ability to resist external forces applied to the grasped object. We rely on grasp quality metrics derived from the Grasp Wrench Space, a method traditionally used for quantifying robotic grasps. We illustrate this approach by studying human grasps of a spherical object under a number of different disturbances. Our results indicate that the quality metrics we use can help explain the subjects´ choice of contact points, although other possible grasping strategies may exist.