Enhancing digital video analysis of bar kinematics in weightlifting: a case study

Abstract

Weightlifting technique can be objectively assessed from two-dimensional video recordings. Despite its importance, participants’ bar trajectories in research involving the snatch or clean exercises are often not reported, potentially due to the time required to digitize video. The purpose of this investigation was to evaluate the use of an LED-based marker, digital video and open source software to automatically track the bar end during weightlifting exercises. A former national-level weightlifter was recorded with a digital video camera performing the snatch, clean and jerk, and squat exercises. An LED-based marker was placed on the right end of the bar. This marker was automatically tracked using two open source software programs to obtain vertical and horizontal position coordinates. The LED-based marker was successfully auto-tracked for all videos, over a variety of camera settings. Further, the vertical and horizontal bar displacements, and vertical bar velocity were consistent between the two software programs. The present study demonstrates that an LED-based marker can be automatically tracked using open source software. This combination of an LED-based marker, consumer camera and open source software is an accessible, low cost method to objectively evaluate weightlifting technique.