Sep 8

Written by: Larry Huppin, DPM
9/8/2011 1:26 PM

I just had a client call asking if there was any way to increase arch height on an orthosis. There are a couple of options, but first, let’s discuss arch height for a moment.

There are a number of studies that indicate that orthoses that conform closely to the arch of the foot are likely to be more effective at treating many of the most common complaints that we treat with foot orthoses – including plantar fasciitis, metatarsalgia and hallux limitus.

In order for an orthosis to conform close to the arch of the foot, several things must happen in the casting, prescribing and manufacturing of the orthosis:

• Cast with the first ray plantarflexed
• Prescribe a minimum cast fill with 2 or 3 degrees of inversion
• Use an orthotic lab that does not overfill the medial arch

When the above occurs and you receive the orthosis back from the lab, the device should conform close to the arch of the foot when the foot is held in neutral position with the first ray plantarflexed.  You can see this in the picture at left.   Compare that to the gapping that you see in the picture on the right.

Now, back to our client’s question – what if the orthosis doesn’t conform close enough to the arch? By the way, in this client's situation, the orthosis is gapping from the arch because the doctor prescribed a standard fill orthosis with no inversion.

Here are two methods to increase arch height

1. Add a varus wedge to the orthosis. A varus wedge added to the heel post will invert the orthosis and act to increase the relative height of the orthotic arch
2. Add an arch pad under the topcover.

ProLab clients are encouraged to contact one of our medical consultants for any questions regarding orthotic prescriptions.

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