Monday, December 18, 2006
put a spring in your step
A couple of months ago, I had the idea that if somehow my shoes were spring-loaded, I might be able to achieve what, for me, is the hardest part of walking –– pushing off with my toes. I talked to my physical therapist about this and she arranged a consultation with an orthotist who recommended a pair of custom-made prosthetics to do the job. Yesterday, I went for a fitting for my new ankle braces.
Things have changed a lot since the days of plaster bandages, or since the times I’ve had “life-casts” made of my face for theatrical make-up classes.
The orthotist, Jesse, first covered my feet and legs below the knee with cotton stockings, on which he marked the position of a few landmarks like my ankle bones and toes. Then he immersed a roll of fiberglass tape in a pail of warm water and wrapped this around my legs. As he was doing this, we were continually chatting. I was in the middle of a sentence when I noticed that Jesse had a mat knife in his hand. He started cutting down the front of my shin and I thought, "He's really careful with that knife,” before I remembered that he put a plastic shield on my leg when he started wrapping it.
The really surprising part was that this fiberglass tape was completely hardened in about one minute. Jesse simply slit it down the middle, peeled off my leg and stood it up in the floor.
He told me the next step in the process would be to make a plaster “positive” of my leg from this mold. They would then build up certain areas on the model of my leg, and finally create a thermoplastic brace around the model using a vacuum-form table.
I asked him about how my back brace might been made. When I was fitted for that brace, I was flat on my back, and unable to move, so the orthotics specialist took a series of measurements, and what they probably did was use a computerized lathe. The measurements are entered into a computer program that controls a machine, which sculpted a singled torso-sized slab of plaster to create a template. A sheet of soft, hot plastic was drawn over the model of my torso, and sucked down tight on a vacuum-form table until the plastic cooled and hardened.
This whole process apparently goes pretty quickly, as I should be getting my new braces before the New Year.
Pretty cool, huh?