01/25/2024    Jeff Root

MI Podiatrist Discusses Excessive Pronation (Robert Scott Steinberg, DPM, Richard Stess, DPM)

I appreciate the points presented by Drs. Stess,
Steinberg, and Radovic. Unfortunately, I’m not
aware of any reliable, scientific method for
comparing the contour of slipper casts to that of
direct foot scans. I’m also not aware of any good
outcome studies that support one method over the
other clinically. In the lab, we have made
orthoses of the same subject using multiple
techniques and then we compare the shape of the
finished orthotic shells to the positive models
produced using other techniques. This is the only
way I’m aware of to compare the contours of
orthoses made from a fully manual process (slipper
cast to corrected, positive plaster cast), a
partially manual process (a scanned slipper cast
to computer generated positive wood mold) and a
fully digital process (direct foot scan to a
computer generated positive wood mold). Our goal
is to create the same shape of device with all
three methods. While, when done properly, there
may be subtle differences in shape, the extent to
which these shape differences are clinically
significant remains unknown.

The manual cast to manual, corrected positive
model technique, and the CAD/CAM techniques all
rely on the science and art of the individuals
making the negative cast/scan and the positive
model. The lab technician’s protocol, knowledge of
anatomy and a variety of other factors all
influence the end product. As a result, good or
poor quality orthoses can be made using any of
these techniques or systems. It’s certainly
possible to make a poor quality orthosis from a
good slipper cast or a good foot scan. Educating
podiatrists and labs about how to produce good
quality orthoses has been an integral part of my
long career as both a lab technician and lab
owner/director.

In my opinion, there are some labs who produce
consistent good quality orthoses with any of these
techniques and other labs that don’t appear to
produce consistently good quality orthoses with
these or other techniques. As a result, the making
of a good quality orthosis requires a chain of
quality that begins with a proper biomechanical
examination, an appropriate Rx, a good cast/scan
of the foot and good lab technique. In other
words, it requires a team effort from start to
finish.

Jeff Root, President, KevinRoot Medical

Other messages in this thread:

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01/25/2024    Jeff Root

MI Podiatrist Discusses Excessive Pronation (Robert Scott Steinberg, DPM, Richard Stess, DPM)

I appreciate the points presented by Drs. Stess,
Steinberg, and Radovic. Unfortunately, I’m not
aware of any reliable, scientific method for
comparing the contour of slipper casts to that of
direct foot scans. I’m also not aware of any good
outcome studies that support one method over the
other clinically. In the lab, we have made
orthoses of the same subject using multiple
techniques and then we compare the shape of the
finished orthotic shells to the positive models
produced using other techniques. This is the only
way I’m aware of to compare the contours of
orthoses made from a fully manual process (slipper
cast to corrected, positive plaster cast), a
partially manual process (a scanned slipper cast
to computer generated positive wood mold) and a
fully digital process (direct foot scan to a
computer generated positive wood mold). Our goal
is to create the same shape of device with all
three methods. While, when done properly, there
may be subtle differences in shape, the extent to
which these shape differences are clinically
significant remains unknown.

The manual cast to manual, corrected positive
model technique, and the CAD/CAM techniques all
rely on the science and art of the individuals
making the negative cast/scan and the positive
model. The lab technician’s protocol, knowledge of
anatomy and a variety of other factors all
influence the end product. As a result, good or
poor quality orthoses can be made using any of
these techniques or systems. It’s certainly
possible to make a poor quality orthosis from a
good slipper cast or a good foot scan. Educating
podiatrists and labs about how to produce good
quality orthoses has been an integral part of my
long career as both a lab technician and lab
owner/director.

In my opinion, there are some labs who produce
consistent good quality orthoses with any of these
techniques and other labs that don’t appear to
produce consistently good quality orthoses with
these or other techniques. As a result, the making
of a good quality orthosis requires a chain of
quality that begins with a proper biomechanical
examination, an appropriate Rx, a good cast/scan
of the foot and good lab technique. In other
words, it requires a team effort from start to
finish.

Jeff Root, President, KevinRoot Medical