Step change: How 3D printing is benefitting foot orthotics

Lee Dockstader, HP 3D Printing Business, explains how 3D printing is reshaping foot orthotics.

For as dramatic a difference medical foot orthotics can have on someone’s quality of life, the process of making them remains pretty low tech and slow, often taking weeks from the initial doctor appointment to get the orthotics into the patient’s shoes.

3D printing is starting to change that. While 3D printing is just beginning to take hold in the world of medicine, the technology will dramatically change how orthotics are prescribed and produced.

3D printing is revolutionising healthcare in many ways. Surgeons are able to practice complicated procedures on 3D-printed models of their actual patients before ever cutting into their skin. Amputees are getting better fitting replacement limbs. Teenagers with scoliosis can now get braces that perfectly fit their bodies and carry less of the stigma that causes many not to wear them. The majority of hearing aids are manufactured using 3D printing to improve the fit. Every day hundreds of thousands of medical parts are 3D printed, mainly in the medical segments of orthodontics, dentistry, audiology and orthopaedics.

People suffering from flat feet, unusual walking gaits, plantar fasciitis, bursitis, tendinitis, diabetic foot ulcers, pain or other serious problems require more than just over-the-counter arch supports, heel liners or foot cushions. They need custom-made medical orthotics from a trained medical professional. Traditionally, custom orthotics have been made by taking a mould of the patient’s foot and the doctor then recommending an orthotic size and shape based on an examination of the foot mould and the patient’s gait over a few steps. For the most part, that method has worked, but has a number of dependencies and is not 100% effective. The traditional model relies heavily on human judgment, the doctor’s eyes and a trained orthotic technician, leaving room for human error.

Mark Twain famously said the difference between the almost right word and the right word is the same as the difference between the lightning bug and the lightning. That is true of orthotics too. A millimeter or two of incorrect foot measurement has a ripple effect: not only would the contour of the insole be off, but the patient could experience leg or back pain as a result and then have to go through the process again.

Plus, it usually takes a few weeks from the time the doctor orders the insole for it to be manufactured and delivered. In some ways, that’s really fast, but if you’re a patient struggling with pain, it can feel like an eternity.

It’s also unnecessary. With the capabilities of 3D printing, doctors can now use specialised pressure plates to analyse each individual’s dynamic walking or running gait. The plate and accompanying software called footscan 9 from RSscan International can measure the properties of 10 different zones of the foot while still and in motion. It analyses not only arch shape but ligament and joint stress, muscle activity and movement throughout the rear foot, midfoot and forefoot. That level of specific calculation throughout the foot is simply not possible with visual examination and some plaster of Paris. A proper foot orthotic is less likely to be created from a static foot analysis and observing someone take a few steps. Even more challenging are photogrammetry based solutions that take a picture of your foot with a smartphone. 

With dynamic gait analysis, once the specific dimensions and shape of the orthotic have been determined, manufacturing the orthotic is simply a matter of printing the PA 12 plastic orthotic base with an HP Jet Fusion 4200 3D printer or comparable device and affixing it to a fabric insole pad.

Improving how orthotics are prescribed and produced will also likely help millions of people who don’t suffer from severe foot problems but do have some discomfort or fear of injury. The pressure plate, software and 3D printed shoe insert would likely benefit anyone with comfort or stability issues.

High-performance athletes and runners often order custom-made shoes and insoles to make sure their feet hit the ground correctly. Some land on the inside edge of the foot and roll outward. Some land on the outside edge and roll inward. Some run with toes angled out, some angled in. There is an ideal way the foot should make impact with the ground to maximise comfort and minimise the possibility of injury, and orthotics can help – if they are designed correctly.

With 3D printing and the associated foot scanning and analysis technology, doctors will be able to produce better orthotics more quickly. More importantly, millions of people may be able to walk and run without pain, something most of us simply take for granted.  This same technology, but with less range of corrections, will also be available to consumers in the not too distant future.