what-when-how
In Depth Tutorials and Information
Casted foot orthoses
The comments made about the merits of prefabricated foot orthoses
should not be read to mean that orthoses made from a cast of the
foot are never necessary: they are. The exception to rule regarding
routine use of prefabricated rather than bespoke orthoses is the foot
with a known structural deformity, which will not be adequately accom-
modated by any prefabricated orthosis. This deformity may be the
result of disease, such as Charcot-Marie-Tooth, Charcot changes or
advanced rheumatoid foot disease, or prior traumatic injury. It might also
be the case that a patient has a foot structure that is at the extremes of
normal variation, and therefore using an off-the-shelf orthosis (which is
designed close to an average foot shape) is not advocated. Casted
orthoses do offer the opportunity to completely tailor the choice of materi-
als for the patient, which can be critical in cases of diabetes and other at
risk feet.
Overall, the clinical and biomechanical effects of casted and prefabri-
cated orthoses are likely very comparable in the general population; and
other factors dictate their use, such as cost and time. For the at risk foot,
the use of casted orthoses is more easily justified given the consequences
of high loading on specific sites of the foot. Even then, however, there
are ample prefabricated orthoses available in many cases, and the
expense of casted orthoses should be left to those patients whose foot
health poses a significant clinical challenge.
'Which orthosis type is best?'
This is a common question but there is no simple answer; indeed, it is
the wrong question to ask. The pertinent question is, 'Which shape and
material of foot orthosis works best for this specific patient?' In most
cases, a prefabricated orthosis can be found that offers appropriate clini-
cal outcomes.
It is critical when evaluating evidence relating to the efficacy of foot
orthoses that conclusions are not incorrectly extrapolated to all orthoses
of a similar design. Evidence that one specific casted orthosis is better at
controlling pronation of the foot is not evidence that all casted orthoses
perform this function better than prefabricated orthoses. The data relate
only to the specific orthosis tested. A different casted orthosis could have
the opposite result when compared with an alternative prefabricated
orthosis. So, do not attempt to classify your practice by the manufacture
method of 'type' of orthosis, but rather consider which orthosis offers
what you decide each patient requires.
