The All-Terrain Foot
David Mathews, CP
Ernest Burgess, MD
David Boone, CP
ABSTRACT
In the past, people who managed to survive the traumatic loss of a leg or even
those born with a major limb deficit required an ambulatory aid for functional
mobility. The peg leg was developed under these circumstances and has remained with us throughout history.
Since it continues to be used by many
amputees regardless of other options
they may have, the peg leg remains valuable. Prosthetics Research Study has
designed a new lower-limb terminal device called the All- Terrain Foot.
Introduction
Evolution of lower-limb prostheses
over the centuries is well recorded not
only in medical and engineering literature but also in the very fabric of history. Upper- and lower-limb amputees
and their replacement devices have
been depicted in lay history, fiction and
folklore. The front entrance of the
famous old Pioneer Hotel in Lahaina,
Hawaii, is graced by a wooden statue of
a sailor with a lower-limb amputation
and peg leg; and most children learn
the tale of Long John Silver while still
in grade school.
The peg leg-with some means of
crude socket or cup receptacle for the
residual limb-is the earliest recorded
prosthetic device. The limb could be
held on manually as the individual
walked or be suspended by a variety of
systems, usually shoulder suspension
or bandaging. Below-knee amputees
used a bent-knee prosthetic socket as
an attachment.
A number of lower-limb amputees in
Third World as well as in industrialized
countries still use these systems today
even though remarkably functional
and cosmetic prosthetic systems are
available. In what circumstances might
a person use such a simple device?
The Device
The All-Terrain Foot (ATF) is not a
new concept; however, it has been improved significantly for occupational,
recreational and practical uses. The
foot is made of a durable rubber that is
compression molded around a stainless
steel washer (see Figure 1
and Figure 2
). The convex surface on the bottom was designed to allow for a smooth
transition throughout the gait cycle.
and photographic analysis of gait was
used to determine the heel contact angle (1). The ATF can also be interchanged with the Seattle Lightfoot?
without requiring any height or alignment changes.
People with amputations who work
in a wide variety of occupations have
found the ATF to be a beneficial alternative to newer prostheses. Loggers in
the Pacific Northwest have difficulty
with the conventional foot because of
uneven terrain and climbing over logs.
through brush, vines and fern. The uneven terrain frequently encountered by
farmers (see Figure 3
) and landscapers also makes
the ATF functionally appropriate for
them since it improves maneuverability, and the foot does not get stuck,
caught or tangled.
The ATF functions well for water-related activity as well, including showers, swimming and beach walking.
Stream fishermen find it convenient for
wading. Also, it is much easier to get
out of a kayak should the craft turn
over.
To date, few problems have been
identified with the device. The attachment hole through the bottom may fill
with mud or snow, but this can be remedied by plugging the hole with a commercially available material such as
neoprene cord or Shoe Goo? It has
also been noted that the ATF can be
slippery on smooth surfaces unless the
surface "skin" on the bottom is worn
off or sanded initially.
David Mathews, CP, is research prosthetist for Prosthetics Research Study, 720 Broadway, Seattle, WA 98122; (206) 328-3116.
Ernest Burgess, MD, is director and principal investigator for Prosthetics Research Study.
David Boone, CP, is chief of research presthetics for Prosthetics Research Study.
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