Hugh Herr lost both of his to frostbite as a teenager but bionic limbs have enabled him to carry on the activity he loves – climbing.
The double amputee is only too happy to show off how science has helped him beat adversity and proved it by scaling this 60m (200ft) rock wall.
Even though one of the prostheses fell off during the attempt, he calmly roped it back up and re-attached it before carrying on.
The 47-year-old, who runs a lab that makes bionic legs at Massachusetts Institute of Technology, in the US, reckons his artificial aids have an advantage over human limbs.
‘It’s really sad to have biological limbs, you’re constrained by nature and you can’t upgrade,’ he said. ‘The artificial parts of our body are immortal.’
He claims technology will eventually eliminate disability and extend human capabilities.
‘At some point, the prosthesis will be a transportation device, like a car,’ he added. ‘Amputees will be able to walk with less energy than a person with biological legs.’
Mr Herr lost his legs aged 17 after climbing Mount Washington in New Hampshire with a friend in 1982.
They became stranded in a snow blizzard and spent three nights in sub-zero temperatures before a rescuer found their footprints.