Two artificial big toes – one found attached to an Egyptian mummy
and one located in The British Museum – may have been the world’s
earliest functional prostheses, according to University of Manchester
researcher, Jacky Finch, who tested replicas on volunteers as part of her PhD
study.
Changing history
Finch has shown that these devices were not added on after death as some
other prostheses from this time period, but aided in walking.
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| Jacky Finch with replicas of the devices, which were used by volunteers. |
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| Images: The University of Manchester |
“The cartonnage [Greville Chester] toe has been in The British
Museum since 1881.” Finch told O&P Business News.
“The three-part device was found [in] 1999 [or] 2000 by the German
Institute of Archaeology, Cairo with the Supreme Council of Antiquities Egypt
in a Theban burial ground opposite present day Luxor. This tomb contained some
estimated 73 individuals who had been buried there much later than its original
owner. Most of the bodies were fragmentary. The ‘toe’ was strapped
onto the foot of a female mummy [aged approximately 50 years to 60 years
old.]”
The toes date from before 600 B.C., predating what was previously
thought to be the earliest known practical prosthesis – the Roman Capua
Leg – by several hundred years.
Something Different
Finch is not new to the world of studying prosthetic relics. During her
master’s of science in biomedical and forensic Egyptology study at the
University of Manchester, she studied a “rather crudely made artificial
left forearm that had been added to an Egyptian mummy by the embalmers before
burial,” she explained.
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| Volunteers in the study found the Cairo toe particulary comfortable. |
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“I came across many such embalmers’ restorations plus these
two ‘toes’ which struck me as being very different. The wear on the
Greville Chester toe and the important design features on the Cairo toe led me
to speculate that these toes were perhaps worn by their owners in life and not
simply attached to the foot during mummification for religious or ritualistic
reasons,” Finch stated.
Proof
Finch explained that the research necessary to classify an artifact as a
prosthesis is specific, involves many experts and is time consuming. The
material must withstand bodily forces so that it does not snap or crack with
use, and the appearance must be sufficiently lifelike as to be acceptable to
both the wearer and those around him/her. Most importantly it must assist
walking.
“I thought it a great challenge for my doctoral thesis,” she
said. “I took images of both ‘toes’ to Glyn Heath, PhD, School
of Health, Sport and Rehabilitation Science, University of Salford … He
suggested the only way to prove if they worked was to try them out.”
Replica tests
Finch, who is based in the University of Manchester’s KNH Centre
for Biomedical Egyptology, recruited two volunteers whose right big toes had
been lost in order to test exact replicas of the artificial toes in the Gait
Laboratory at Salford University’s Centre for Rehabilitation and Human
Performance Research.
“Each of my two volunteers had a replica of each toe which they
tested plus replica Egyptian sandals.”
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| The Greville Chester toe has been in The British Museum since 1881. |
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While neither design was expected to perform exactly like a real big
toe, one of the volunteers was able to walk well with both artificial toes. No
significant elevation in pressure under the foot was recorded for either toe,
although both volunteers said they found the Cairo toe particularly
comfortable.
“I found the whole experience exciting … I just felt so
strongly that if credit was due to the ancient Egyptians and not the Romans
then someone needed to tell the world,” Finch said. “There may be
older devices yet to be discovered. I feel fairly confident that no older ones
are out there already. The history of prosthetic medicine usually starts with
the Capua Leg … so what I am proposing is indeed rather extraordinary.
Experimental archaeology is time-consuming … but I enjoyed the whole
challenge and hope that I have made some difference.” — by
Jennifer Hoydicz
Loss of the great toe can significantly impact balance both statically
and dynamically. In static conditions, the great toe assists balance by making
slight postural adjustments by way of the hallux muscles and associated
intrinsics, providing contact and position information to the nervous system
via skin, muscle and joint receptors and also by interacting with the entire
kinetic chain.
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| M. Jason Highsmith |
Dynamically, the great toe has a role in transitioning the body’s
center of pressure from lateral to medial as well as posterior to anterior in
normal walking. The keel lever of the foot is extended in a compliant
structural fashion by virtue of the great toe’s osseous structure and
muscular support in late stance. The great toe permits us to maximize our step
and thus stride lengths while simultaneously giving us additional foot surface
area over which to distribute potentially injurious forces.
When the great toe is amputated, the normal pressure transition is
disturbed such that progression is no longer available as far medially and
anteriorly as was the case with the great toe intact. With unilateral
amputation, step and stride lengths become asymmetric and foot pressure
increases, in part, from lost surface area. Regardless of unilateral,
bilateral, static or dynamic situation, when the center of mass is outside the
base of support, some degree of instability is present. Loss of the great toe
affects the available base of support and thus in some regard, stability is
also affected.
Evidence of the importance of the function of the great toe is apparent
by considering the fact that a great toe prosthesis exists that predates
written history. To this day, researchers are still attempting to fully
understand the many ways great toe amputation affects balance, stability and
gait. Similarly, clinicians are seeking best management strategies to preserve
the great toe, amputate in such a way as to preserve as much anatomy as
possible or to prosthetically replace the great toe’s lost functions when
necessary.
— M. Jason Highsmith, PT, DPT, CP,
FAAOP
Assistant professor, School of Physical Therapy &
Rehabilitation Sciences, College of Medicine, University of South Florida
