All Topics Prescribing Scanning

Foot Scanning & Casting:
Applying our skills to modern technologies.

I think someone said "easy..." ?

Casting, scanning, assessing and submitting foot modelling data is easy right? Press a button, lights flash, the magic processing wheel turns, a 3D foot appears on our screen. Press another button and the lab has all they need!

Foot printing clinician Ian Drakard takes us through the processes of casting and/or scanning in preparation for sending information to a manufacturing lab…

" Modern technology correctly applied "

How to cast and scan...?

Look out for upcoming discussions on the types of scanners, but I’m going to use this blog to set out some thoughts on how to cast and scan, so when we look at individual scanners you know where we’re coming from.

Now I’ve seen some pretty fierce arguments about the way casts and scans should be done, so I’m not expecting you to agree with everything, but hear me out ok?

I’ll also use cast and scan somewhat interchangeably at times, because I just mean the method of volumetric capture.

So, what are we trying to achieve with the scan? As someone who has spent years designing orthoses around scans, not only for other clinicians but also my own patients, I can’t repeat this point enough; the closer the scan to the final shape of the device you want to achieve, the easier the process and the greater the chance of a successful outcome.

Footprint Hubs Stuart Roeszler has done an excellent blog on communication here, and the scan is a huge part of communicating the shape we want to end up with. I’m confident I could get a similar looking cast from 2 sets of feet with very different mechanics. So when I’m teaching people to cast or scan, I show them the basics, but the point always comes back to not just does it reflect the foot, but does it reflect the device geometry you are thinking of? Where the device is higher or lower will influence the magnitude and vector of the orthotic reaction force applied to the foot.

The prescription forms we see have not changed from the days of plaster. Most labs don’t use a separate form for digital scans or plaster casts or foam boxes. But the form options are the same. Expansions, arch fills etc all have the same check boxes.

So, suppose I take a traditional suspension plaster cast, loading the lateral column, and a digital scan with the foot left hanging. I’m not going to tell you which one is better, because that’s not the point. Suppose I fill in the same boxes on the prescription form. I should end up with 2 different shaped devices right?

But the patient is the same…

Either that or the person doing the designing has made a load of assumptions I didn’t ask them to make to get to a different shape – in which case what’s the point of the prescription?
  • Can all these advances de-skill us in other areas?
  • Do we get so wrapped up in how much quicker, easier and more streamlined everything is that we forget some of the core principles of what we’re doing?
  • Does it even matter?

  • The simple answer to the above is YES. For a lot of the things we do (and say we do)… as an industry, current technology has a de-skilling effect. It is much quicker and easier in exchange for a bit of “loosening” of our protocols and effects the customised nature of the product(s) we produce.

    A quick PodByte for you...?

    ” The advent of modern technology has not changed the need for a clear understanding and communication process to deliver information essential for manufacturing. The assumptions contained within the tech has, in real terms, made it more important to follow a clearly defined, industry recognised clinical process “
    Every now and then, something comes along that makes sense. Knowing the extreme value of these little cherubs, we have compiled them into a series called the ” PodBytes “. Look for them on your journey through our site or on the bottom of communication to a fro. Please feel free to use these podbytes to help jog your memory, ease the day or share your knowledge with a friend.
    In simple terms, communication is the process by which an accurate exchange of information occurs between individuals and/or groups of people. Good communication is evidenced by all parties satisfied with the resulting action / products generated by the interaction. Read more here.