This chapter briefly reviews four issues: (1) Single-digit contacts, (2) multi-digit grasps, (3) constraints on digit forces and (4) prehension synergies. In the section on the single-digit contacts the main models of contact (the point model, hard-finger contact and soft-finger contact) as well as slip prevention are considered. A subchapter on multi-digit grasps is a tutorial-like introduction to grasp mechanics, in particular to the concept of grasp matrices. The following issues are addressed: (a) vertically oriented prismatic grasps, (b) grasp matrices, (c) non-vertical prismatic grasps, (d) arbitrary grasps, (e) virtual finger and (f) internal forces. The constraints on digit forces are classified as mechanical and biological. Among the biological constraints force deficit and finger enslaving are addressed. Inter-finger connection matrices and their use for reconstruction of the neural command are discussed. Prehension synergies, experimental methods of their research, and the principle of superposition are described.: To manipulate hand-held objects, people exert forces on them. Performers grasp objects in different ways. A simplest classification of the grasps (or grips) includes two varieties: a power grip when the object is in contact with the palm of the hand (e.g. holding a tennis racket) and a precision grip when only the digit tips are in contact with the object. The present chapter deals with the precision grip.: Single-digit contacts: This section concentrates on two issues: modeling the digit contacts and slip prevention.: Modeling the digit contacts: Contact is a collection of adjacent points where two bodies touch each other.
|Original language||English (US)|
|Title of host publication||Sensorimotor Control of Grasping|
|Subtitle of host publication||Physiology and Pathophysiology|
|Publisher||Cambridge University Press|
|Number of pages||19|
|State||Published - Jan 1 2009|
All Science Journal Classification (ASJC) codes