Blog entry posted by dunetraveller, Dec 23, 2010.

A little rant tonight. Everyone at work seems to love looking to see if I wear my VFF KSOs everyday. I am asked about them almost daily. Today one of the department supervisors was wondering what her employees were geeking out about. I am a courier for my company and part of my delivery duties involves delivering plastic boxes of quarters. A "can" of quarters weighs 12.5 pounds. I am always asked if I am worried that something might fall on my foot (like a can of quarters). I always respond that "of course I worry about it, but that it makes me more aware of my surroundings", thereby reducing the odds of an accident to almost nil.

Still, they seem to think their shoes provide great, or even complete protection. I then respond that the amount of material in their shoe uppers don't provide any more protection against crushing impact than mine do, but that they labor under the illusion of safety. They seem to nod a bit in agreement when they think about it, but you can tell they think their safety is assured and I'm possibly crazy.

I spent an hour or possibly more looking on various physics websites to find the calculators I needed to verify the actual force my foot would be subjected to if by some unimaginably bad stroke of luck, a can of quarters fell from a height onto the top of my foot. Long story short, the impact from 3.5 feet above would be around 4700 Newtons, and from 5 feet would be around 6600 Newtons. One 70 kg man results in around 686 Newtons of force against the Earth from the effects of gravity. So my coworkers somehow believe that the thin flexible uppers of athletic or dress shoes will provide protection from impact equal to 1000 - 1350 pounds resting on a small spot on top of their foot (can you say ouch? and get me an ambulance?). On the upside: a steel toe boot meeting the latest standard could resist all the force and then some.

I always thought I was right in assuming the damage done by a falling object would do injury, but it's quite another thing to actually do the math. Everyone at work might as well be barefoot for all the protection afforded by their choice in footwear (the company does not require safety shoes and no one I have seen has worn them in my 10+ years at the company), but I anticipate that my boss will finally come around to see what I am wearing and insist I wear "normal" shoes for "safety". One can hope a little science lesson will suffice?

Sorry for the approximations for the figures quoted, but once I did the calculations I promptly misplaced the information, and I had to go from very fuzzy memory, but I am pretty close anyways.