Arch height/fill for your orthotic prescription. Here are a few tips to consider
The arch height of your orthotics is something that you will have to decide on for every prescription. It’s one of the most important parts of your prescription as it can determine comfort and results. So, how do you determine the arch height you want and what options are there?
Fill is what most people will use to determine their orthotics’ arch height. That said not many people know what it means in terms of the figures.
0 fill – Means the shell is contacting the arch of the scan.
Minimum fill – means the arch height is reduced by 10% from the arch height of the scan.
Standard fill – means the arch height is reduced by 20% from the arch height of the scan.
Maximum fill – means the arch height is reduced by 30% from the arch height of the scan.
This is why your scan is important. Your scan will determine the arch height you will have if you prescribed in % fill. For example, if you use a flatbed scanner and scan the foot in a supinated position your starting arch height will be higher. If you scan the foot pronated your arch will start from a lower position.
When prescribing like this it is always a guess as to how high the arch will come back as you don’t know the exact mm you started with. But it is a good base to the amount of movement you want the foot to have.
Prescribing in mm
This is why CAD CAM is so good. You can prescribe the exact arch height you want to the nearest mm. Mark the high point of the arch using a pen. Place the foot in the position you will perform the scan then, using a ruler, take a measurement. You can then decide in mm how high you want it.
Prescribing in mm also gives you consistency with your orthotics. If you prescribe in mm you will know exactly how high your arch will come back. If you prescribe by % fill you will not be sure.
wondering what factors contribute to determining your medial arch height? Check out our next blog here.
For more help with your prescriptions contact us today.