Four years ago, Tigst Assefa was told she would not run again, but she went on to break the women's marathon world record in spectacular style on 24 September Tigst Assefa needed just 18 months to go from marathon debutant to smashing the world record by more than two minutes. The Ethiopian's astonishing Berlin race – winning in two hours, 11 minutes and 53 seconds – intensified attention on "super shoes" after she ran in a pair using "unique technology". BBC Sport Africa has been speaking to the 26-year-old, her coach Gemedu Dedefo and other experts to discuss Assefa's next…