Custom made foot orthoses (shell only) are manufactured to a specific measurement 3-5mm behind the metatarsal heads and follow the metatarsal parabola.
All sulcus length and full length, covers are made to standardised shoe size templates used in the Firefly lab for consistency. Technicians follow these templates accurately.
Data in the form of 3D scanned images and plaster of paris casts, non weight bearing, arrive daily in our lab. We also receive semi weight bearing and fully weight bearing foam impressions.
The key information we require from our podiatrist clients include body weight to choose shell thickness and shoe size to complete sulcus or full length covers. The data in any format proximal to the MTPJ’s is not used to size top covers as the foot position varies from scan, to plaster and foam.
Toe box shape varies from shoe brand to shoe brand and shoe type which means unless we have a specific template sent with the order, we will use the lab standardised templates to finish top covers. They quite often require trimming to fit with sharp scissors and if possible, a mini grind to polish edge. Although most clinics do not have grinders and a good set of sharp scissors will suffice.
Shoe sizing measurement systems also vary from UK, EU and USA. Therefore comparing different measurement systems is like comparing apples with oranges and confusing. How they are used can lead to the potential for confusion around sizing.
In Firefly’s lab, we match from the plantar aspect of the orthoses to the template– as demonstrated in the video above. Therefore, adjustments to the length of the top cover can be made with a sharp scissors in clinic and there is no requirement to send the devices back to Firefly for recover.
If two different shoe sizes are requested for left and right foot, e.g. a 5 for the left and a 5.5 for the right, the assumption is made that the patient will wear a pair of shoes to fit the larger foot. Seldom do we see a patient purchase two different pairs of shoes to get accurate shoe sizing for each foot.
Therefore, the template chosen will be for the larger foot size and an assumption that the podiatrist will fit to shoes and allow the smaller foot to sit short of the template size.
Style of shoe must be considered as some device types e.g. Impact Sport, Diabetic Tridensity and RA Soft Mould devices can be quite bulky due to their design and palliative nature. In such cases, we recommend sidecuts and undercuts to make them more slimline – please discuss with Firefly’s Technical Support team if you anticipate this should be considered in device design.
