Two ancient Egyptian wooden toes have been confirmed as the world's oldest prosthetics, according to scientific tests.
Involving two volunteers who were both missing their right big toe, the test are reported in the Journal of Prosthetics and Orthotics.
"A brief paper was published in the Lancet in February 2011, but it did not contain the data from the study," Jacqueline Finch, a researcher at the University of Manchester’s KNH Centre for Biomedical Egyptology, said in a statement.
Discovered in the necropolis of Thebe near present-day Luxor, the two artificial toes — the so-called Greville Chester toe housed in the British Museum and the Tabaketenmut toe at the Egyptian Museum in Cairo — have been called by several experts the earliest prosthetic devices in existence.
Exquisitely crafted from cartonnage (a sort of papier maché mixture made using linen, glue and plaster) the Greville Chester toe dates from before 600 BC and comes in the shape of the right big toe and a portion of the right foot.
The other false toe, a three-part wood and leather artifact dating from between 950 to 710 B.C., was found attached to the right toe of a mummy identified as Tabaketenmut.
She was a priest's daughter who might have lost her toe following gangrene triggered by diabetes.
Both fake toes show significant signs of wear. Moreover, they feature holes for lacings to either attach the toes onto the foot or fasten it onto a sock or sandal.
"There are many instances of the ancient Egyptians creating false body parts for burial, but the wear, plus their design, both suggest they were used by people to help them to walk," Finch said.
"To try to prove this has been a complex and challenging process involving experts in not only Egyptian burial practices, but also in prosthetic design and in computerized gait assessment," she added.
The researcher created two reproductions modelled as the Greville toe and the Tabaketenmut digit, along with replicas of leather ancient Egyptian-style sandals.
Each volunteer was asked to walk on a 10-meter walkway barefoot, in their own shoes and wearing the toes with and without sandals.
Finch filmed the volunteers’ walking gait using 10 video cameras, while the pressure of their footsteps was measured using a special mat. The 10 best walking trials were recorded for each foot, using their normal left foot as the control.
The camera footage revealed that when wearing the sandals with the cartonnage replica, one of the volunteers achieved 87 percent of the flexion achieved by their normal left toe. The three-part wood and leather design producing nearly 78 percent.
"Interestingly, the ability to push off using the prosthetic toe was not as good when this volunteer wasn’t wearing the sandals," the researcher wrote.
The second volunteer didn't perform as well, but was still able to produce between 60-63 percent flexion wearing the replicas with or without the sandals.
According to the pressure measurements, there were no overly high pressure points in both volunteers, indicating that the false toes were comfortable and not causing any tissue damage.
When the volunteers wore just the replica sandals without the toe prosthesis, significant differences in peak pressures were recorded. This indicated that "it would have been very difficult for an ancient Egyptian missing a big toe to walk normally wearing traditional sandals," Finch said.
"They could have remained barefoot or perhaps have worn some sort of sock or boot over the false toe, but our research suggests that wearing these false toes made walking in a sandal more comfortable," she added.
The volunteers were also asked fill in a questionnaire about how they felt when doing the tests in the gait laboratory.
Despite having performed well, the Greville Chester cartonnage replica wasn't comfortable. On the contrary, both volunteers found Tabaketenmut's
three-part wooden and leather toe extremely comfortable.
The performance and perceived comfort of this replacement means that "nascent prosthetic science may have been emerging in the Nile Valley as early as 950 to 710 B.C.," Finch and colleague Ann Rosalie David, professor of biomedical Egyptologyat the University of Manchester, wrote.
The three-part example pre-dates by some 400 years what is currently thought to be the oldest, although untested, prosthetic device. This is a Roman leg made out of bronze and wood in around 300 B.C, known as the Capua leg.
The leg was destroyed by Second World War bombings and only a replica now remains.
Photo: The Tabaketenmut toe kept at the Egyptian Museum in Cairo. Credit: University of Manchester.
– Scientific tests using replicas of the ancient Egyptian artificial toes. Credit: University of Manchester.