Human Odometry with a Two-Legged Hopping Gait: A Test of the Gait Symmetry Theory

Abstract

Biological odometry refers to the capacity for perceptually measuring distances traveled during locomotion. In the case of haptic odometry, information about distance traversed is generated from the movements of the legs, with coordinated leg motions (i.e., gait patterns) producing patterns of tissue deformation detectable by the haptic perceptual system. The gait symmetry theory of haptic odometry classifies gaits based upon the symmetry of muscle activation patterns. This classification identifies candidate higher-order variables of haptic odometry and provides a promising basis for understanding the associated patterns of tissue deformation detected by the haptic perceptual system. The theory successfully predicts biases (i.e., underestimations/overestimations) resulting from the manipulation of the gait patterns used in the outbound and return phases of homing tasks. We test gait symmetry theory by considering a previously unexamined key prediction. Two-legged hopping and walking have the same symmetry group classification, therefore, a homing task completed using any combination of two-legged hopping and walking as the outbound/return gaits should produce no systematic biases. Contrary to this prediction we observed systematic biases. We discuss the possibilities for modifying gait symmetry theory to account for our findings, and we present a new alternative theory based upon spatial reference frames.

Acknowledgements

Special thanks must be given to Hannah Holbrook, Benjamin Gross, and Amanda Ivey of Colby College, who assisted in the implementation of the experiment.

Disclosure statement

The authors declare no competing or financial interests.

Funding

This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

Notes

1 The experiments of Schwartz (1999) show that report distances are unaffected by measure phase variations in step amplitude/frequency when these gait parameters are self-selected and consequently possess a ‘natural’ or ‘typical’ covariation with gait speed.