I’m assuming we have already determined the style of AFO for the patient, by history, physical assessment, gait analysis, biomechanics +/- an Elaine Owen algorithm will get you so far as to exclude certain types. We don’t have enough space here to discuss the process outlined above, so will leave that topic for another time.
But what I’m asking, is now that we have clinically one of the largest choices of stock AFO’s, and as Orthotist we are largely autonomous in our clinical decision making, what are the most important reasons to you in reaching a final clinical decision on the product? For example when faced with ordering a lightweight carbon AFO with an anterior shell, how do you choose between the several on offer? Cost? Customer service?
Initially it’s largely based on experience and trial & error, feedback from colleagues and as general rule with stock AFO’s, I consider the following design term F3: Fit / Form / Function.
Ideally the AFO should be designed by reversing those, most important being the function, which will ultimately define the form and then fit. However it is often the F3 priority that sees form take priority over function and these are the items that we see fail, often problematic with fit.
Function – Do we perform the biomechanical task well and uphold the force principles over time? If adjustability is offered, do we perform this both easily and well? An AFO offered with a trimmable footplate, but which leaves a sharp edge, or is best performed under extraction means for certain clinicians an unusable function that creates more work. Do straps work and not fail, are padding & soft goods anatomically correct and working to protect and unload? Does the AFO articulate, are the joints anatomically located, does it even have a joint to allow a dynamic articulation – if so how can you be certain a dynamic AFO pivots at the correct point without a joint?
Form – Are we light, strong enough to uphold the corrective forces, do we have footplate pitch? A must for myself. Build quality and longevity are not always in line with purchasing cost. Max weight limits, good selection of sizing and ratios of footplate to finish heights are sometimes make or break for supply on certain clients. Quality of materials, some pre-preg carbon layups are superior to others. Is the out toe correct?
Fit – Are all interfaces smooth, are edges flexible, can they accommodate anatomical movement in gait, or small fluctuations of size? It is a stock AFO and as such it should have the ability to have some tolerance to movement, as an example the calf band. A fixed calf band or those which are not heat mouldable exclude a lot of clients and as such these would not be the first to be trialled personally. If modular / articulating, do the parts fit and have tight tolerances, do replacement parts fit and interconnect well. Personally a neutral footplate I find more useful as a preformed shaped footplate is likely not to fit all feet and it’s easier to add an insole to the neutral footplate for any M – L concerns. If a full length footplate, does it actually fit a shoe. Foot piece struts distort the shoe, some are worse offenders than others.
We understand the multiple other variables that may determine your choice, and we would like to generate a discussion and hear your thoughts on your decision making.