Footnotes

• Contributors Y-JT was involved in the conceptualisation, crafting of the draft manuscript and review of the final manuscript. CHT and CC were involved in obtaining and editing the video and figure used in this study, and the review of the final manuscript.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Provenance and peer review Not commissioned; externally peer reviewed.