RIO DE JANEIRO (AFP) - United States distance runner Abbey D'Agostino has been ruled out of Friday's 5,000m final after suffering a knee injury in her dramatic collision with New Zealand's Nikki Hamblin.

A statement from USA Track and Field (USATF) on Wednesday said D'Agostino had suffered tears to her right anterior cruciate ligament and meniscus and strained ligaments, ending her season.

D'Agostino had been granted a place in Friday's final despite finishing outside the qualification places in Tuesday's heat at the Olympic Stadium.

The American runner earned plaudits for helping New Zealander Nikki Hamblin back to her feet and into the race in a widely praised gesture of sporting behaviour.

"I'm so grateful for Abbey for doing that for me. That girl is the Olympic spirit right there," said Hamblin, who was also granted a place in the final despite not qualifying.

Both women eventually limped over the line after helping each other complete the race.

D'Agostino's exploits earned her a front page cover on the New York Post daily on Wednesday, with the tabloid describing the incident as "a story that reminds you there is good in the world".