Again I'm assuming that you will have seen this incident on TV - in the second heat of the women's 5000m, which featured Almaz Ayana ETH (winner of the 10000m in a magnificent new World Record time a few days earlier).
"In addition, there was bloody drama four-and-a-half laps from the end.
With the pack closely grouped together as they chased Ayana, New Zealand's Nicky Hamblin and USA's Abbey D'Agostino accidentally tripped over one another, the latter badly twisting her knee in the process.
Both ended up on the ground, with Hamblin sporting a big gash to her ankle, but they picked each other up and limped their way through the rest of the race, determined to finish and record a time rather than see DNF (did not finish) beside their names in the results.
The referees later sympathetically advanced the pair, along Austria's Jennifer Wenth who was also impeded in the collision but not as seriously, advanced to the final." - part of the Report from Phil Minshull of the IAAF.