Recurrence-based phase synchronization analysis of digit kinetic signals during precision grip

Abstract

The inter-digit coordination during precision grip was assessed using a recurrence-based phase synchronization (PS) analysis in this study. The PS across the normal forces of the thumb and index finger with respect to the contact surface serve as a critical dynamical strategy underlying precision grip. When both the thumb and index finger had reduced tactile sensitivity, the PS of Fz increased compared to the conditions with normal digit tactile sensation. This result suggested a compensatory mechanism relying more on the feedforward control with reduced tactile sensory information. The PS analysis would shed light on the mechanisms of digit-force coordination and facilitate assessment of sensorimotor function in patients suffered from neuropathies.