Russell Crowe Reveals He Fractured Both Legs During Robin Hood Shoot: 'I Just Kept Going' (Exclusive)

Russell Crowe has always been game to do a lot of his own stunts. But there was one "small mishap" on the set of his 2010 Robin Hood that later became a much bigger deal.

"I jumped off a castle portcullis onto rock-hard uneven ground," the Oscar winner, 59, tells PEOPLE for One Last Thing in this week's issue. "We should have prepped the ground and buried a pad but we were in a rush to get the shot done in the fading light."

Crowe, who is currently starring in the new action thriller Land of Bad, didn't realize the precarious situation until he was about to jump.

"With hundreds of extras around, arrows flying and burn pots setting the castle on fire, there was no pulling out," he recalls. "As I jumped, I remember thinking, 'This is going to hurt.' "

Aiming to land on the balls of his feet to help with the impact, the actor felt his heels hit the uneven ground first. "It was like an electric shock bursting up through my body," he says. "We were shooting a big movie, so you just struggle through, but the last month of that job was very tricky. There was a number of weeks where even walking was a challenge."

Crowe "never discussed the injury with production, never took a day off because of it, I just kept going to work," he adds.

A decade later, Crowe began having what he calls "very strange pains" in his lower legs so he went to a doctor for an MRI and X-rays.

"I thought it was nothing serious," he says. "After working through a long New York winter, my body was just missing exercise and sunshine."

The star was shocked when the doctor looked at the X-rays and asked him, "When did you break your legs?" "Apparently he could see the remnants of fractures in both shin bones," says Crowe. "To jog my memory he said, 'Would have been maybe 10 years ago?'"

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Crowe immediately remembered jumping off the portcullis on the Robin Hood set. "Apparently I finished that movie with two broken legs," he adds. "All for art. No cast, no splints, no painkillers, just kept going to work and over time they healed themselves."

Looking back, the actor realized after the shoot wrapped in 2009, he took a year off and didn't work until signing on for 2013's Man of Steel.

"In retrospect I obviously knew something was wrong," he says. "To be the Kryptonian father of Superman was six months of incredibly intense physical training. Between the time off and that training, things fixed themselves."

Land of Bad in now in theaters.