A Manchester University team hope to prove that the leather and wood "Cairo toe" not only looked the part but also helped its owner walk.
They will test a replica in volunteers whose right big toe is missing.
If true, the toe will predate the currently considered earliest practical prosthesis - a fake leg from 300BC.
The Roman Capua Leg, made of bronze, was held at the Royal College of Surgeons in London but was destroyed by Luftwaffe bombs during the Second World War.
Lead researcher Jacky Finch said: "The toe dates from between 1069 and 664BC, so if we can prove it was functional then we will have pushed back prosthetic medicine by as much as 700 years."
Colleagues at the University of Salford will also be testing a second, even older ancient Egyptian big toe which is currently on display at the British Museum.
This artefact, from between 1295 and 664BC, is made from cartonnage, a kind of papier-mâché made from linen, glue and plaster.
Like the Cairo toe, this too shows signs of wear, suggesting that it was worn by its owner in life and not simply attached to the foot during mummification for religious or ritualistic reasons.
Güncelleme Tarihi: 28 Temmuz 2007, 11:36
However, unlike the Cairo toe, it does not bend, suggesting it may have been more cosmetic.
Jacky Finch said: "The Cairo toe is the most likely of the two to be functional as it is articulated and shows signs of wear.
"It is still attached to the foot of the mummy of a female between 50 and 60 years of age. The amputation site is also well healed."
The Cairo toe is on display at the Cairo Museum in Egypt.