The kindness of strangers has been revealed in a video that showed the aftermath of the moment a young motorcyclist was T-boned by a driver on a busy Adelaide road.

Footage of the incident, filmed on the biker's helmet, shows the man spot the turning car seconds before the moment of impact.

"S---," he says, before the camera and its wearer are sent tumbling across the road.

For a moment the man seems alone, but as he looks up the helmetcam captures scores of drivers rushing to his aid.

A doctor tends to the injured biker as other concerned motorists call an ambulance.

"Are you okay?" a woman asks. "We need to get him out of danger," another man declares.

The motorcyclist, who did not wish to be identified, shared the video online weeks after the undated incident, saying he suffered ligament damage in his knee.

"I could barely walk for a few weeks … Other than that I was fine!" he wrote.

"Thanks to everyone who stopped to help," he added.

The man said the driver of the car that hit him was found at fault by police for failing to give way.