Proprioception Is Robust under External Forces

Irene A Kuling,Jeroen B J Smeets,Eli Brenner

doi:10.1371/journal.pone.0074236

Abstract

Information from cutaneous, muscle and joint receptors is combined with efferent information to create a reliable percept of the configuration of our body (proprioception). We exposed the hand to several horizontal force fields to examine whether external forces influence this percept. In an end-point task subjects reached visually presented positions with their unseen hand. In a vector reproduction task, subjects had to judge a distance and direction visually and reproduce the corresponding vector by moving the unseen hand. We found systematic individual errors in the reproduction of the end-points and vectors, but these errors did not vary systematically with the force fields. This suggests that human proprioception accounts for external forces applied to the hand when sensing the position of the hand in the horizontal plane.

Highlights

When making a goal directed movement, information from both vision and proprioception is used to identify the position and orientation of the hand [1,2,3,4,5,6,7]
The errors are comparable for all force fields, but the pattern of errors differed considerably between the two subjects, which is consistent with the subject-specific patterns of errors found in other experiments [8,9,10,11]
We found that the force fields influenced the amount of extra path, which shows that the forces did have an effect on the movement paths

Summary

Introduction

When making a goal directed movement, information from both vision and proprioception is used to identify the position and orientation of the hand [1,2,3,4,5,6,7]. Despite the ease with which we perform such tasks, there is evidence that subjects have considerable biases when matching proprioception to vision [8,9,10,11]. These biases suggest that the calibration of our senses is far from perfect. In this study we examine a complication of proprioception that may contribute to such biases: external forces

Methods

Results

Conclusion