Belgium's Philippe Gilbert eats a snack following his crash on the 16th stage of the Tour de France. (Photo: AFP)

Belgian Philippe Gilbert's Tour de France campaign is in the balance after he was taken to hospital for further scans following a spectacular crash into a ravine on stage 16.

Quick-Step veteran Gilbert was 57.2 km from the finish and in the lead of the 218km-long 16th stage on Tuesday when he negotiated a bend badly and flew headfirst over a wall.

Although he was helped back onto his bike to finish the stage, won by French teammate Julian Alaphilippe, Gilbert emerged from the X-ray truck suffering from his endeavours.

"He has been taken to hospital in Toulouse for further scans," a Quick-Step spokesman told AFP.

The race medical report said the former world champion had suffered "damage to his left knee".

Quick-Step bosses panicked when Gilbert went over the wall -- it was on the same descent, albeit several kilometres below, that Italian Fabio Casartelli died in a horrible crash in 1995.

Negotiating a left-hand bend at speed, Gilbert failed to brake in time, skidded and was sent flying head first over a parapet to land on rocks several metres below.

Television pictures showed officials helping him to climb back out and onto the road, where he jumped gingerly back on his bike to finish the race.

"I'm happy to be here," Gilbert said.

"We played it well. I attacked to put a little bit of pressure on our group, I wanted to help Julian.

The injured elbow of Belgian Philippe Gilbert, who crashed into a ravine on stage 16 of the Tour de France. (Photo: AFP) 

"Tactically, we did well, but I crashed and it was all my fault. I simply took the wrong line.

"I fell onto rocks and, when I landed, I thought I'd been broken apart. I've had a lucky escape."

The race ends Sunday on the Champs Elysees in Paris.