June 2015

The argument for library-based orthotic prescription

6Delcam-Sidebar-Picture1-copyBy Jordana Bieze Foster

Much of the discussion at the 2015 Ortho Technology Forum (OTF) focused on various ways in which the future of the orthotic industry will require adapting to new technologies. But the event’s final presenter challenged OTF attendees to consider the possibility that the future of the industry will also require reinventing the entire process of orthotic prescription.

Scott Marshall, co-owner of KLM Laboratories in Valencia, CA, noted that industry professionals who have been making custom foot orthoses have likely noticed, as he has, that a majority of the devices fall into recognizable and predictable shape categories. This phenomenon makes the industry particularly well-suited, he said, for a scientific library system in which most devices are made from premanufactured shells or positives or pre-engineered digital shape files.

“What if certain shapes are used over and over again? This is what optometrists do; that’s why you can get glasses in about an hour,” Marshall said.

What makes the proposed library system scientific is that the shape categories would be defined by specific measurements calculated from years of data on devices that were created using more traditional means of orthotic design and manufacturing.
KLM’s ongoing analysis of its database of 367,755 plaster casts and digital foot scans has revealed four key measurements that dictate device shape:

  1. Length from the bisection of the first metatarsal head to the most proximal aspect of the heel;
  2. Apex of medial arch height along the bisection of the first metatarsal shaft when the cast is placed in the balanced or prescribed position;
  3. Apex of lateral arch height when the cast is placed in the balanced or prescribed position; and
  4. Heel width across the middle of the heel, at the widest part.

After identifying the range for each measurement that accounted for the majority of devices in the database, Marshall and colleagues estimate that a library system of 4680 reproducible foot shapes would accommodate most patients’ needs. The library models could also easily be adjusted, mathematically and objectively, by increasing or decreasing one of the four key measurements.

This type of system could allow most patients to get high-quality orthotic devices at a single visit, and at a lower cost than with current processes, Marshall said. It could also provide a scientific means of tracking and studying the performance of different orthotic configurations on the same patient or on patients with particular deformities.

“The time has come to revisit how we prescribe orthotic devices, and to redefine what a custom orthotic is,” Marshall said.

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.