The crash occurred on Thursday during a quarter-final heat when Van Riessen lost control of her front wheel and slid across into the path of Marchant, before both riders fell.

Van Riessen received medical treatment for several minutes on the track before she was put on a stretcher and taken down the tunnel for further assessment.

Marchant managed to get back up and finish the race but failed to qualify for the semi-finals.

"It's not my day is it," Marchant said.

"We were all fighting a bit on the inside and I'm not sure if someone hit into Laurine or what but she came down in front of me and I had nowhere to go."

Marchant said she would be back for Friday's individual sprint event.

"(I'm) a bit battered and bruised but I'm all right."

Van Riessen was trapped between two riders entering the final lap of the race.

Her front wheel suddenly dodged to the right, wiping out Marchant and sending both of them to the track.

The keirin is a six-lap race in which riders follow a motorised bike for the first three laps.

It slowly picks up speed before leaving the track, leaving the riders to sprint the final three laps to the finish.

Australian Associated Press