Will orthotics weaken my feet?

Classically braces can cause muscular weakness to occur because they support the braced area thereby negating the need for the muscles to actually do any work.  Subsequently the muscles become weak over time from inactivity.  However, a properly constructed foot orthotic does just the opposite.  By aligning the bones of the foot and subsequently the bones and joints of the entire body into a more corrected, functional and efficient position, the total contact orthotics provides a stable framework for the body to become stronger by allowing the muscles of the body to function in a symmetrical, even and consistent manner thereby avoiding injury due to overuse from functioning in an imbalanced position. 
I've had orthotics before that didn't work, why should I think that yours will?
In short, there are no guarantees that anything will work, but with this being said, this orthotic technology is a proven to work system that places the bones of your foot in a more corrected and subsequently functional position.  Many orthotics do not achieve that as they are made using a different technology.  The orthotics that is used by your doctor are total contact orthotics which are uniquely different than anything else on the market.  It is advised that you communicate your concerns and experience to your doctor before you get started so that they can firstly assess why the previous orthotics did not work for you and secondly, so that they can explain to you why the total contact orthotics will in fact work to handle your particular situation if they believe that it can in fact be handled to your satisfaction.