Human radius, by Bob Myers.
Bob Myers, Science Teacher at West Ottawa High School, Michigan
CC BY 3.0
From YouTube video "Pectoral Limb Walk-thru". Video URL is <a rel="nofollow" class="external free" href="https://www.youtube.com/watch?v=Exe4h9qcJqE">https://www.youtube.com/watch?v=Exe4h9qcJqE</a>