EFFECT OF THE MECHANICAL CONSTRAINTS ON MULTI-FINGER PREHENSION

Abstract

INTRODUCTION: When a finger produces a force, other non-task fingers of the hand also produce an involuntary force. This phenomenon has been known as finger enslaving (Zatsiorsky et al. 1998). In the present study, we examined the characteristics of the enslaving matrices obtained by the fixed object prehension and the free object prehension. Previous studies showed that two innate constraints (i.e. peripheral and central constraints) affect the performance of finger force production during fixed object prehension. However, it is unknown how the mechanical constraints, which are imposed externally, play a role in grasping tasks. The purpose of the current study was to investigate the finger enslaving for the fixed and free object prehension during maximum finger force production tasks in statics. The central nervous system (CNS) is required to satisfy linear and rotational equilibrium during the free object prehension, while the CNS does not need to satisfy any external constraints