I said I would post when I found out what UCBL stood for...
It is an orthotic that was invented by University of California Berkley... the 'L' stands for something in the orthotic world - unknown at the moment (the therapist just temporarily forgot). It is made out of hard white plastic - is constructed from a cast made of the child's foot and is used to keep the child's foot in a more balanced structural position. It's used early on in life so that the structure grows in a more normalized position.
I have pictures of it if anyone is interested,
francine