The barest of margins has separated Lauren Mitchell from a first Australian artistic gymnastics Olympic medal.

Mitchell finished fifth at the North Greenwich Arena last night after a floor exercise final won by America’s Alexandra Raisman, who scored 15.600.

Romania’s Catalina Ponor (15.200) took silver and Russia’s Aliya Mustafina (14.900) won bronze.

The WA Institute of Sport gymnast, who scored 14.833, admitted the difference between a medal and the disappointment of missing out was something as simple as a slight foot movement.

“I’m a bit relieved that it’s over,” Mitchell said. “(I’m) relieved that I did everything I could in training. I was 0.066 away from a medal so that’s pretty damn close.

“Feeling my routine then watching the other girls’ routines, their execution felt like it looked cleaner than mine.

“So I don’t think I could’ve overtaken them anyway. I think it probably would’ve been more heartbreaking to come equal and just because of the execution come fourth. I’m happy where I am.

“I wanted to perform my routine and I hope that’s what the judges saw, what everyone saw.”

Since the Melbourne Games in 1956, Australian artistic gymnasts have tried - and failed - to force their way on to the podium.

Australia’s only gymnastics medal was won by Ji Wallace when he claimed silver on trampoline at the 2000 Sydney Games.

But the cupboard in artistic gymnastics remains bare after last hope Mitchell was unable to improve on her qualifying score to take a step on to the podium.

The 21-year-old admitted feeling the pressure of expectation going into the final.

“Yesterday, I was really, really nervous,” she said. “I was sitting in the stands watching the other girls do finals. And it was just like the butterflies, the dead legs.

“I let myself feel that yesterday and I woke up this morning and came in early and had a podium session.

“I let myself feel that nervousness again when we first presented up to the judges then went back into the warm-up gym.”

Mitchell, who was hindered by an abdominal injury last week, was ranked fifth in qualifying and went into the final hoping for a medal.

But despite showing the determination that has epitomised her career, she fell agonisingly short.

Twice a silver medallist at the world championships in 2009, Mitchell also won gold on floor in the sport’s elite competition in Rotterdam two years ago.

On both occasions, she had set new ground for Australian gymnastics and she had been tipped to continue to break through the barriers last night.

A shoulder injury in the lead-up to London had prompted her to drop bars from her program as she chased success on the floor and beam.

And then, in the days before qualifying in London, she suffered the stomach strain.

Mitchell became only the third Australian to reach an Olympic individual apparatus final after Lisa Skinner competed on floor in Sydney 2000 and WA’s Allana slater, who competed in beam four years later.

Both gymnasts had falls in their finals to ruin their chances of picking up a medal.