A common question we have received through the years from safety managers and their employees is whether or not a particular style has a shank. More often than not we find the person is really seeking a steel plate.
What do you think of when you hear the word shank? Do you picture a really bad golf shot? A piece of meat? A homemade knife? In footwear a shank is a supportive piece in the middle-part of the shoe between the heel and ball area to help provide arch support.
Many people think a shank provides puncture resistance, i.e. the ability to prohibit the piercing of footwear by a foreign object. A shank or “shankpiece” is most often rectangular about the size of a piece of chewing gum. Some newer styles trying for extra arch support have slightly different shapes but the relative size and purpose are the same. Shanks provide arch support in a variety of work environments such as climbing ladders or working on railroad ballast; but by no means is a small shankpiece going to provide puncture protection. A shoe needs a full length and width plate made with specialized materials to be able to achieve true puncture resistance.
Puncture-resistant plates provide underfoot protection relative to their materials, size, and shape. There are traditional metal versions as well as alternative non-metallic versions. The most important thing to affirm is that they are compliant with ASTM F2413 Puncture-Resistant requirements. Puncture-resistant footwear should be worn in work environments with bottom hazards such as nails, needles, metal shards and other potential sharp or dangerous items. This type of footwear is most commonly used in steel manufacturing plants, waste disposal and recycling oriented job places as well as a wide variety of construction sites.
A common misconception about puncture-resistant footwear is that the puncture plate makes a shoe or boot completely inflexible. Generally, the reason puncture-resistant shoes are slightly more rigid than other safety shoes is due to a harder outsole that offers an additional layer of protection. Technology has improved dramatically over the years when it comes to the rigidity of puncture-resistant footwear; and today’s styles provide bend and flexibility to be more comfortable and functional.
Occupational Health & Safety online had a good article by Wayne Elsey in 2006 about the need for puncture-resistant footwear and safety footwear in general.