These days, there are multiple ways to manufacture ‘Orthoses’ (plural of Orthotic).
Steps involve taking a plaster cast of the foot, making plaster modifications to correct the foot mould, polypropylene (PPE) or carbon fibre material heated in an oven and then vacuum moulded over the modified plaster cast. Most of the process was done by the Podiatrist, or the cast sent to a professional laboratory for manufacture.
Either a plaster cast or directly scan the foot using a laser scanner, the resulting data is then sent via email with a prescription to a commercial laboratory for a technician to convert the data into a usable file for a computer generated orthotic. A robotic machine carves out the shape of the orthotic from a solid block of plastic (PPE) or rubber (EVA). More waste biproduct but cheaper to make and more adjustable with a heat gun than Digital printed.
Steps are the same as Milled device, but now the data is used to input a Digital printer, whereby the orthotic is slowly built by liquid material slowly added together and hardens. A very slow cooling cycle is required. This device takes a minimum of 48 hours to produce, but there is little waste material. More expensive than milled.
While perfecting this art, I was very reluctant to move into the 21st century, but in 2019, I took the enormous step of acquiring a High Definition Laser Scanner required to prescribe Computer generated orthoses. This has been a very positive step for my patients as the orthoses are lighter, thinner and generally more user friendly than the older style of orthotic.
The heated polypropylene used in the manual method is a minimum of 4mm thick, whereas the milled devices are between 2.2mm and 3.5mm depending on your weight.
There has also been a slight drop in the overall cost since the days of fully manual manufacture.
The digital capture can be kept for many years without storage issues. Casts were kept by the client for 10 years or by the Laboratory for 2-3 years.
I am now fully confident in using the Milled orthotic method, and in time, this will easily convert over to digital printed technology.
At the time of writing an Orthotic prescription, a discussion can be had with each client as to the balance between cost, environmental issues and other various functional issues the two types of technologies present.