We hate swimming backstroke. It seems unnecessarily awkward and splashy, you can't see where you're going and the timing is tricky.We have four limbs. With apologies to ZZ Top , we just don't know how to use them.Double arm amputees Zheng Tao and Iaroslav Semenenko finished first and fourth in the men's S6 100m backstroke final on Thursday evening, competing against swimmers with more limbs whose equivalent disabilities still allowed them to use a much more recognisable backstroke technique. Zheng also broke the world record.It's well worth checking out the whole race below, despite Barcelona breaststroke bronze medallist Nick Gillingham 's discordantly soporific commentary. Zheng is in lane 5, Semenenko in lane 3. Do keep a sympathetic eye on Semenenko as he battles bravely for bronze against a German swimmer whose arms give him a clear advantage at the finish line.Just thinking about the incredible core strength and balance required to overcome their handicap in this event, not to mention the dedication and tenacity that brought them here, is pretty overwhelming. Zheng and Semenenko's achievements will stick with us as one of the enduring images of London 2012.