Can anyone tell me where the bar wedge pad is supposed to be placed on the shoe? Is any part of the pad supposed to be hanging off the back?

How the back of the pad is fit depends on the conformation of the foot and the shoe fit. (as with any wedge pad) . Fitting the back of pads is quite subjective.
Do you have a specific problem with one and need answers? If so, pictures might help.

calshoer wrote:

Actually, I have two horses on my route that have stretched soles. I talked with you about this a couple of weeks ago. And you gave a good explaination. They have no heels, and grow no heels, and stretched soles. After you shoe them it doesn't take long before they look long again. I thought that a bar wedge pad would help by getting them off of their heel bulbs and backing the toe as far as possible to change the angles.

I would trim the heels back as much as you can, fit the shoe heels long ,and fit the back of the bar wedge to the ends of the shoes. And grind or bevel the top edge of the pad at an angle to help prevent shoe pulling.
I have a couple of "stubborn" cases in my practice that no matter how many times they have had everything set back ,trimmed back, wedged, sole support, whatver, they still grow forward in 6 weeks, its just their conformation, so don't lose too much sleep over it.

calshoer wrote:

Thank you for the reply.

calshoer wrote:
What do you do with the excess trim left on the inside of the pad? I assume trim it out so that it is not blocking the commisures.

The bar wedges have a hollow side and a flat side... depending on the foot and degree of prolapse or sensitivity across the frog I'll use the hollow side or the flat side. A sensitive frog may start with a leather frog sling on a wedged shoe ( a great tool I "stole" from Patty). Depending on foot conformation I may allow up to half an inch of plastic behind the shoe and bevel it in. A more upright foot the pad usually ends at the heels of the shoe. I would allow dirt and shavings to fill under the barwedge...I'd see it as free bar support (unless you have a major mess).
Whenever I hear the phrase "no heels" I'm curious about what is meant. Do they not grow tall, bend forward or are they just not upright?
Jason

In Califiornia where my clients were mostly stalled, I used to leave it open under the bar, (which usually covers about half the frog)but now the environment is different so I fill under just the bar portion with equipack to keep out rocks. Here in Colorado all we have is sand ,gravel and rocks.