In this photo provided by TED 2014 Conference, dancer Adrianne Haslet-Davis, front, performs on stage with dancer Christian Lightner at the 2014 TED Conference, Wednesday, March 19, 2014, in Vancouver, British Columbia. Haslet-Davis took to the stage to perform for the first time since losing part of her left leg in the 2013 Boston Marathon bombing. (AP Photo/TED 2014 Conference, James Duncan Davidson)
Haslet-Davis wipes away a tear while standing on stage with MIT professor Hugh Herr, left, and dancer Christian Lightner, at the 2014 TED Conference. Herr designed the bionic leg specifically for dancing after visiting Haslet-Davis in the hospital. (AP Photo/TED 2014 Conference, James Duncan Davidson)