Michaela Binder examines evidence of Europe’s earliest known artificial foot.
Grave 6 contained an adult male whose left foot had been amputated – note the difference in size of his lower leg bones – and replaced by a prosthesis.
Though people have lived on the Hemmaberg, a mountain settlement in southern Austria, since Neolithic times, our research focuses on a small cemetery that belongs to the period shortly before the site was destroyed in the 6th century AD.
The 27 graves of men, women, and children lie at the top of the hill, close to the church, signifying their high social-status within the community in the manner characteristic of early Christians. Most were typical burials of this period, with simple rectangular pits and very few grave goods. But one stood out: the man in Grave 6.
He was about 35-50 years old when he died, and he had endured various health issues in life, including dental problems, a fractured jaw, and a broken nose. Most striking, however, was the fact that his left foot was missing. In its place was an iron band 1.5-1.8cm wide, 0.3-0.4cm thick, with a diameter of 6.8-7.3cm, and closed with two small iron rivets. Preserved on the inside were the remains of heavily deteriorated wood, fixed to the iron by four iron nails. Dark staining in the grave and on the remaining lower leg attest to the presence of a deteriorated organic substance.
This metal band is all that remains of the prosthesis, and is the earliest known example in Europe.
Examination of the shin bones showed that his left foot had been lost 10cm above the ankle, but that new bone had formed on the stumps of the tibia and fibula. This indicates that, though there had been some initial infection, he survived the injury, which was well healed by the time he died several years later. The iron band, therefore, must be part of a prosthetic device to compensate for the amputated foot.
Though the earliest known prostheses are associated with 2,600-year-old Egyptian mummies, and we have pictorial representations from the Roman period, we have only one early example of an artificial lower leg from Europe: a wooden core sheathed with bronze recovered from a Roman-era grave in Italy in 1884/1885. It is unclear whether it was functional or simply cosmetic. Sadly, the original was destroyed during a bombing raid on London in 1941, but we have a cast of it in the Science Museum, London.
A leather pouch with a wooden sole fixed with iron found in Switzerland is contemporary with the Hemmaberg find, but because it was fixed to the remaining stump of the lower leg, it almost certainly could not be used for walking, as it would have come off immediately. Moreover, considerable osteomyelitis with a lack of atrophy suggests the owner died within a year of their injury. So, until the Hemmaberg find, the earliest archaeological evidence for a functional prosthesis dates to the 7th/8th century AD, from Griesheim, Germany.
Standing on both feet
Though we do not know why the left foot of our man in Grave 6 was amputated, the most plausible cause is some form of violent or accidental trauma. To learn more about his injuries, the bones were submitted to the new bioarchaeology lab at the Austrian Archaeological Institute, Vienna.
Normal living bone-tissue is constantly remodelled through continuous bone formation and bone resorption. Immobilisation of a limb leads to a marked imbalance in this process. Due to the removal of mechanical loading, formation slows down significantly, while resorption remains largely unaffected, resulting in decreased bone density and structural weakness.
X-rays of his thigh bones revealed a marked difference in density between the amputated and healthy leg. This shows he was unable to put pressure on the foot for at least one or two years. However, once he was mobile again, bone density would have increased. A higher degree of joint degeneration in the left knee reveals that the leg was used differently – further proof that he was walking on it – and advanced osteoarthritis in the left shoulder but not the right suggests he used a crutch for support.
Dr Michaela Binder, Austrian Archaeological Institute