Pramod Karan Sethi, who died Sunday at 80, was inventor of the Jaipur foot, a prosthesis that has enabled millions around the world to walk again and work productively at minimal cost.

Especially popular in war zones from El Salvador to Cambodia, where land-mine injuries hobble thousands, the foot can be constructed in just 45 minutes out of locally available materials, including rubber from tires and scrap aluminum.

In Afghanistan, spent artillery shell casings have been recycled as legs. They are distributed in war zones by the International Committee of the Red Cross, and also manufactured locally in many places.

The foot was named for the northern Indian city where Sethi’s worked as an orthopedic surgeon. Sethi invented the foot in 1968 after becoming frustrated with expensive, clunky western-produced prostheses. Even patients lucky enough to afford them would frequently become frustrated and throw them away, he told the British Medical Journal in 2004. He set out of develop an artificial limb that could be used by farmers in wet fields and that was adapted to the Indian lifestyle — including kneeling for prayer and sitting on the floor.

“Wearing shoes, which were integral to the Western designed limbs, was uncomfortable in our hot climate,” Sethi said. “Our people walk barefoot or in well-ventilated footwear.

“We are essentially a floor-sitting people, requiring a range of mobility in our feet and knees which is not needed in the chairsitting culture of the West. We should not expect our people to change their lifestyle because of a design we were forcing on them.” With the help of a local Jaipur sculptor, he designed a rubber foot attached to an aluminum calf. Key to adapting the design for active walkers was a flexing ankle joint.

The result was so sturdy and flexible that its users reportedly can even climb trees. The leg can be manufactured for about $30. Sethi declined to patent it, spurring rapid adoption.

His invention got another leg up in 1986 in the Bollywood film “Mayuri,” which told the true story of Sudha Chandran, an Indian classical dancer who rehabilitated her career thanks to a Jaipur foot. Sethi was born November 28, 1927, at Agra to a Jain family. His father, a professor at Benares Hindu University, was credited with writing the first physics textbook in Hindi. Sethi studied medicine at Agra, and also was licensed to practice in Great Britain. In Jaipur, Sethi founded an orthopedics department at a teaching hospital and focused on charity cases at a rehabilitation center built for amputees. In India, many young men suffer leg amputations from accidents while riding atop passenger trains.

In 1981, Sethi was awarded the Ramon Magsaysay Award, sometimes considered “the Asian Nobel.”

Despite the millions his invention helped to walk again, Sethi told the British Medical Journal that he felt disillusioned with the younger generation. “I have often advised our young doctors not to rush to make a lot of money,” he said. “My main regret is that I have not been able to pass on my ideology to them.”