Video 1.
Download video file (1.1MB, mp4)
DOI: 10.1136/bcr-2020-236308.video01
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.