Sensors and video for archery training: Taha 2018

The paper describes a computer program that brings together on one screen what can be recorded during an archery training session: three cameras (front, overhead and side) and five wearable sensors. An accelerometer on the pelvis measures body sway, a gyroscope held by a glove on the bow hand is meant to track the movement of the bow, two EMG sensors record a finger flexor and a finger extensor, and a sensor at the wrist picks up heart rate. The data arrive over Bluetooth and appear in real time as graphs beside the video. Separately, results from a psychological skills questionnaire (ACSI-28) and a few physical tests are typed in by hand: vertical jump, standing broad jump, stork balance, grip strength and core strength. The outcome of the work is the programme itself: no measurements on archers are reported.

The programme is written in C# with Microsoft Visual Studio Community 2017, uses the Emgu CV library for the cameras and an internal database that exports to CSV files for sharing between archers and coaches. To cope with three video feeds and five data streams at once, sensor reading is split across parallel threads. According to the authors, the psychological and fitness data, collected every three months or a week before a competition, feed an equation that estimates the archer's psycho-fitness level, but the equation is not given.

There is no validation: it is not known how accurately the sensors measure sway, hand movement or muscle activity, at what rate they record, or whether their data were compared with reference instruments such as a force plate or a motion capture system. Nor is it clear why the EMG sits on two different arms (the extensor on the left, the flexor on the right). The idea that immediate feedback from the coach helps to fix technique is taken from a thesis, not put to the test here. The text itself says that the portable tower for mounting the cameras at the range is still being developed.

For anyone who shoots nothing changes: this describes a tool, not a study of archers. It shows what a Malaysian university group, funded by the National Sports Institute, considered worth measuring at the time (body sway, the bow hand, finger muscle activity, heart rate, mental and physical readiness) and how it can all be put on one screen. Whether these measurements help anyone shoot better, and by how much, remains to be shown.