Tennis Shoe Tech

Well Cross Trainers, but that doesn't create the necessary titular alliteration.

After screwing up both my ankles last week I went out and bought a new pair of sneakers. I had been wearing New Balance 609s which are essentially similar to these. My new pair are 853s. With the higher number came higher price of course. My old shoes were basically cheap generic sneakers. The new ones will help give me the foot and ankle support I need. The neat thing to me, as a former composite materials engineer, is the graphite rollbar built into my new shoes.

When I first went to University of Delaware as a prospective student, the man who would become my advisor for 6 years showed us this neat little widget. It was a little piece of fiber reinforced composite about 8 inches long, an inch and a half wide, and maybe an eighth of an inch thick. The neat thing was that you could bend it all you wanted and stretch it a bit too, but you couldn't twist it if your life depended on it.

When I was finishing my bachelors I took a class on composite structures and I found out how the little dohickey worked. The fiber reinforcement is the strong part and the plastic around it is fairly weak. When you bend it or stretch it, the fiber isn't supporting anything so you can flex it like it was a normal piece of cheap plastic. However the fibers are in the +/-45 degree directions. The engineers who know structures out there will recognize these as directions of shear stress. So if you load it in torsion, a fancy way of saying "twist it", you are pulling on the carbon fiber which is both strong and stiff.

So something like that dohickey is now in my shoes to allow me to run in them, but prevent me from turning my foot the wrong way. Hopefully it will keep me from spraining an ankle in the future.

Oh, after we got to play with the composites we watched a 20 minute video on paint drying. I am not kidding you. One of the fluid mechanicians at Delaware (the Dupont state) does a lot of work on getting even paint coverage on corners/etc. But it was perhaps the dullest thing I have ever witnessed.

Well the dullest thing I have ever witnessed until I was forced to attend a 3 hour breakless briefing this morning.