An unusual experiment. Try putting your finger just above the collarbone and below the Adam’s apple as far as possible until it hurts. I think you can already get quite far in there. But, can you imagine doing the same exercise with a rusty, 10mm thick rebar or reinforcing steel? Neither can I, and yet it worked.
The video here: YouTube
Thanks, Marc Gassert for this experience! (www.marcgassert.de)