Monday, January 14, 2013

Mythbuster: Steel Toe Boots Can Sever or Amputate My Toes So I’m Safer Without Them

This is the number one excuse we hear for guys or girls that just don’t want to wear steel toed boots.  If I had a 30 lb anvil and you had to have it dropped on your toes and I gave you three choices for your feet: 
  1. Barefoot 
  2. Regular work boots no steel toe 
  3. ANSI Approved Steel Toe Work Boots or shoes 
Which would you choose?

Adam and Jamie of the Mythbusters actually covered this subject very well and the myth was totally busted. This was Mythbusters episode 42.  Their final result:
Steel toe boots have a higher amputation risk than regular boots: myth busted


Steel Cap Amputation
Myth: Steel-toed boots are more dangerous than regular boots — if something falls on the boots, the steel can curl in and cut off your toes.


(Remember…this is what the believers of this myth are saying. When something heavy hits the boot toe it causes the steel toe cap in the boot to compress down cutting off the toes. It’s not the object falling on the foot that causes the amputation but the object causing enough force that the steel toe cap in  the boot clamps down, cutting through the foot and bone and severing the toes.)


They were able to find one occurrence of amputation while wearing steel-toed boots occurring in real life. In 2002, an Australian worker lost his 3rd toe when some steel pipes feel from a forklift.


Adam and Jamie constructed various tests for this myth using both a guillotine toe-smasher and an arbor-press. Initially they used frangible feet that Adam made, but it turned out that they made a mistake in assuming that their frangible feet would model real human feet being crushed. For better comparisons they ended up using clay.


Frangible Feet Construction
Adam constructed frangible feet to test with based on landmine frangible feet. After testing chicken legs, bamboo, and fiberglass as substitutes for human bones, he decided to use fiberglass bones. The bones were set in a ballistics gel cast of Adam’s leg.


NOTE: in turned out that the results from this test were somewhat invalid. After testing with the steel-toed boots they tested with the regular boots and discovered that the ballistics gel was too springy and was invalidating their results.


Setup: * Guillotine-style toe crusher that drops a flag metal bar onto the toe of a boot beneath. * Used the highest-rated (ANSI-75) steel toe boots.


Results: * 75lbs from 3 feet (official ANSI test height and weight): mashed the leather down a bit, but nothing injurious. * 400lbs from 3 ft: more deformation in the steel plate, but only damage to frangible foot was a broken metatarsal (big toe). Adam: “I want to see some toes cut off or crushed beyond all recognition” * 400lbs from 6 ft: a lot of pancaking of steel cap and lots of broken bones beneath, but no toe amputation.


They didn’t detail the results from the regular boot because of their discovery about the ballistics gel being too springy.


Guillotine drop on boots filled with clay
Because of the ballistics gel problem they decided to use clay instead of the frangible bone legs they had constructed. Clay is the method ANSI uses to test boots.


At the official test height of 3ft with 75lbs there was 0.5″ of clay compression with the steel-toe boot, which is exactly to spec. The regular boot failed horribly, with the clay being completely splattered.


Arbor press test to find total failure point
They used an arbor press to squish boots to their total failure point. The steel-toe boot was able to take 6000lbs of pressure before total failure; the regular boot was only able to take about 1200lbs, which was hard to measure as it failed so quickly.


Shearing attachment tests
In order to test a worst case scenario, they made a shearing attachment, which was a thin metal plate that would hit the boot on edge. They mounted the shearing attachment to the arbor press: at 750 lbs it broke every bone in the frangible foot; at 1400 lbs it severed all the bones in the feet.


They then mounted the shearing attachment on the guillotine and raised it to it’s max height of 6ft and max weight of 400lbs. The blade glanced off the steel plate, shearing the entire shoe in half. They tested again and got the same result. In this particular scenario, were a heavy blade to drop on your foot you could actually lose more of your foot as the steel cap could direct the glade further up the foot as it did in the test. This isn’t the failure mode described in the tests (remember…the myth is the steel toe cap cuts the toes off…not the object falling), though, and regardless of what type of boot you used there would be amputation.


Mythbusted:
They had to mount a blade in order to get amputation with the steel toe boot and all their other tests showed much more damage to the foot when regular boots are used.


5 comments:

  1. This comment has been removed by the author.

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  2. I saw this episode! I am really impressed how the steel toed boots held up.

    I will never again take them for granted.

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  3. My job requires steel toe with a metatarsal guard to prevent shearing behind the cap. So there are measures to prevent what was a worst case scenario for the show

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  4. I am really impressed with this blog! Very clear explanation of issues is given and it is open to everyone.
    steel suppliers

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  5. I saw this episode a couple of years ago and I had no idea that this would actually happen to me while wearing steel toed boots.
    In late August of 2013, a heavy metal shelf about 6 feet tall tipped over backwards, and came down squarely on top of the steel cap of my boot. It hurt like hell and I figured I fractured a toe at the worst, but it didn't really make sense as to why if it got the steel cap only. That was until I saw the second set of x-rays several days later.
    Those x-rays revealed 4 breaks in 3 toes and they were very clean and straight. What happened was the weight of the shelf and the fact that it was the top that got me hit with enough force to compress the rubber sole which allowed the sharp edge of the cap to snap my toes cleanly. Sort of like a hole punch. Well, in a freak occurrence, I ended up losing my big toe due to severed capillaries at the point of impact. There was no way for them to see that, because of the swelling and bruising. I didn't go to the ER for 2 days.
    2 weeks later, the doctor could see the discoloration and broke the bad news to me. On October 28th, 2013, they removed it.
    Many people tried to say it was because of the steel toe, but the fact is, had I not had the steel toe, I probably would have lost half of my foot. I cited this very episode of Mythbusters several times to the people that insisted I would have been better off without steel toes, but when they get something stuck in their head, there's no convincing them otherwise. If the bones in my foot were as thisck as the bones in their head, I wouldn't even need steel toes at all.

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