This is probably one of the most amazing stories I have ever seen in the realm of  human applied technology.  The man in this video who has been rock climbing since the tender age of 17 lost both his legs to frost bite while doing what he loved.  In a determination to climb again he developed truly bionic legs with substitute technology for muscles and tendons.  It is amazing! Once again proving that whatever the mind of man can conceive the mind of man can do.  Watch this and see if you don't agree.