Sensory weighting of position and force feedback during pinching

Sensory weighting of position and force feedback during pinching

Geelen, J.E. (TU Delft Biomechatronics & Human-Machine Control)
van der Helm, F.C.T. (TU Delft Biomechatronics & Human-Machine Control)
Schouten, A.C. (TU Delft Biomechanical Engineering)
Mugge, W. (TU Delft Biomechatronics & Human-Machine Control)

Biomechanical Engineering

2023

Human hands are complex biomechanical systems that allow for dexterous tasks with many degrees of freedom. Coordination of the fingers is essential for many activities of daily living and involves integrating sensory signals. During this sensory integration, the central nervous system deals with the uncertainty of sensory signals. When handling compliant objects, force and position are related. Interactions with stiff objects result in reduced position changes and increased force changes compared to compliant objects. Literature has shown sensory integration of force and position at the shoulder. Nevertheless, differences in sensory requirements between proximal and distal joints may lead to different proprioceptive representations, hence findings at proximal joints cannot be directly transferred to distal joints, such as the digits. Here, we investigate the sensory integration of force and position during pinching. A haptic manipulator rendered a virtual spring with adjustable stiffness between the index finger and the thumb. Participants had to blindly reproduce a force against the spring. In both visual reference trials and blind reproduction trials, the relation between pinch force and spring compression was constant. However, by covertly changing the spring characteristics in catch trials into an adjusted force-position relation, the participants’ weighting of force and position could be revealed. In agreement with previous studies on the shoulder, participants relied more on force sense in trials with higher stiffness. This study demonstrated stiffness-dependent sensory integration of force and position feedback during pinching.

Fingers
Motor control
Pinching
Proprioception
Sensory integration
Sensory weighting

http://resolver.tudelft.nl/uuid:79681030-8cba-4a19-b83a-161214dbfd27

https://doi.org/10.1007/s00221-023-06654-1

0014-4819

Experimental Brain Research, 241 (8), 2009-2018

Institutional Repository

journal article

© 2023 J.E. Geelen, F.C.T. van der Helm, A.C. Schouten, W. Mugge