Development, evaluation and application of a novel markerless motion analysis system to understand push-start technique in elite skeleton athletes

PLoS One. 2021 Nov 15;16(11):e0259624. doi: 10.1371/journal.pone.0259624. eCollection 2021.

Abstract

This study describes the development, evaluation and application of a computer vision and deep learning system capable of capturing sprinting and skeleton push start step characteristics and mass centre velocities (sled and athlete). Movement data were captured concurrently by a marker-based motion capture system and a custom markerless system. High levels of agreement were found between systems, particularly for spatial based variables (step length error 0.001 ± 0.012 m) while errors for temporal variables (ground contact time and flight time) were on average within ± 1.5 frames of the criterion measures. Comparisons of sprinting and pushing revealed decreased mass centre velocities as a result of pushing the sled but step characteristics were comparable to sprinting when aligned as a function of step velocity. There were large asymmetries between the inside and outside leg during pushing (e.g. 0.22 m mean step length asymmetry) which were not present during sprinting (0.01 m step length asymmetry). The observed asymmetries suggested that force production capabilities during ground contact were compromised for the outside leg. The computer vision based methods tested in this research provide a viable alternative to marker-based motion capture systems. Furthermore, they can be deployed into challenging, real world environments to non-invasively capture data where traditional approaches are infeasible.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Athletes
  • Deep Learning
  • Female
  • Humans
  • Male
  • Motion
  • Musculoskeletal System
  • Skeleton / physiology*

Grants and funding

This research was funded by CAMERA, the RCUK Centre for the Analysis of Motion, Entertainment Research and Applications, EP/M023281/1 and EP/T014865/1 and in collaboration with the British Bobsleigh and Skeleton Association who we thank for their continued time and support with this project. There was no additional external funding received for this study.