Craig PayneThis discussion will never go away. It should.
This discussion over which is better or more appropriate has been on my radar for over 30 yrs now and it still has not been resolved. Not one of the studies (or systematic reviews) has satisfactorily answered the question except for the orthotically naive. If you look at the studies on this that have been done and ask yourself this question: are the foot orthotics that are used in the study typically of the type and design that would commonly be used in clinical practice for the pathology under investigation? Usually the answer is no. The custom made designs are usually some sort of generic prescription missing many design features that would be typically be used for that pathology and the prefabricated designs are just used as a basic shell no one does that in real clinical practice. So we have studies on a basic shell of a prefabricated orthotic vs a generic custom made device, neither with the design features needed for the actual pathology present. No wonder they find no differences.
To illustrate my point further, take for example a patient with some pathology of the posterior tibial tendon. The short to medium term foot orthotic management of that is to reduce the external rearfoot eversion moment. You do that by ensuring that there is some material on the medial side of the point of rotation for that eversion moment and the amount of material there has a sufficient lever arm to reduce that moment. If you got it right, then the load in the tendon is reduced as the posterior tibial muscle then does not have to pull so hard on the damaged tendon. The foot is not going to care if the foot orthotic is custom made or prefabricated as long as it has the design features to reduce that joint moment. Nor will the foot care if its 3d printed or any other high-tech way of doing. What matters is the delivery of the design features to get the required affect.
What if you did a proper well conducted randomized controlled trial of custom made vs prefabricated foot orthotics in those with pathology in the posterior tibial tendon? If the design features in the foot orthotics used do reduce the rearfoot inversion moment, then there will be no difference between the two different foot orthotics. What a waste of research resources is that? What would have been more useful to clinicians would have been a study comparing devices that have the design features to reduce that joint moment vs foot orthotics without those design features. Who cares how those design features are delivered? The foot certainly does not care.
The key is focussing foot orthotic prescription on the delivery of the design features needed to reduce the load in the problematic tissue, not on the type of device to use. What is the point of using some sort of generic foot orthotic prescription, like most of the randomised controlled trials do, which is not specifically aimed at the problematic tissues. Start thinking about delivery the right design features and not the type of orthotic or the process by which that foot orthotic is made.