Modern orthopedic science, combined with space-age technology, has transformed the field of prosthetics. But in much of Asia-and even more so in provincial areas like northern Thailand-modern prosthetic limbs are well beyond the reach of ordinary people who need them. They are too expensive. They are too time consuming to acquire and maintain. Or they are poorly designed for life in the hills and on the farm. This is why poor people who lose legs from accidents or landmines or diabetes (or from snake bites, for that matter), often resort to makeshift alternatives. They fashion substitute limbs from bamboo shafts and spare bicycle parts and from wood and leather and plastic pipes, or they walk on homemade crutches. Observing this some forty years ago, Therdchai Jivacate, a young orthopedist practicing in Chiang Mai, decided he could help them.

Therdchai, a graduate of Chulalongkorn Hospital Medical School who also studied rehabilitation medicine at Northwestern University, began to experiment with cheap and sturdy alternatives to the prosthetic limbs available at his hospital, all of them made from costly imported materials. An early breakthrough involved recycling plastic yogurt bottles to fabricate artificial legs. Using his own money and time taken from his private practice, Therdchai tinkered constantly to simplify the fabrication process and to adapt his devices to local circumstances, creating a "farmer's foot" for working in wet, slippery fields, and another foot for wearing flip-flops. To poor patients, he provided these devices free.

In time, Thailand's late Princess Mother Sri Nagarindra came to know of Therdchai's generous project. In 1992, she lent her patronage to create the Prostheses Foundation in Chiang Mai under his direction. With support from the royal family, private donors, and the Thai national lottery fund, Therdchai was able to expand his work.

Amputees from Thailand's remote borderlands were among the least likely to have access to proper prosthetic limbs. To change this, Therdchai initiated field clinics in which teams of doctors, technicians, staff members, and volunteers bring prosthetic workshops directly to the people. Once on the site, he and his team assess the waiting amputees, make casts of their stumps, mold plastic limbs for each one and then test them for proper alignment, comfort, and "gait." On the sixth day, a custom-made limb is presented to each amputee-anywhere from 150 to 300 persons. To date, Therdchai has organized nearly one hundred of these mobile workshops, including several in neighboring Malaysia, Laos, and Myanmar.

In certain high-need areas bordering Myanmar, Laos, and Cambodia, Therdchai also set up permanent satellite workshops capable of making artificial limbs on the spot. The Foundation equips these workshops and also trains the technicians, who are often amputees themselves. In ancillary activities, the Foundation has organized artificial-leg workshops in Aceh, Indonesia and trained prosthesis technicians from several neighboring countries. Meanwhile, Therdchai himself established Thailand's first and only school of occupational therapy at Chiang Mai University.

Through it all, Therdchai has remained an inventor, assiduously refining his designs and fabrication techniques in cooperation with engineers at the King Mongkut Institute of Technology and other collaborators. His devices cost about 60-80 percent less than the imported alternatives and are durable. Through the Prostheses Foundation, more than 15,000 people have received them free of charge.

Although officially retired, at sixty-eight Therdchai shows few signs of slowing down. He knows that well-made prosthetic limbs not only restore amputees to productive lives; they also restore their self-esteem. His work brings great satisfaction. "Seeing my patients' smiles . . . when they are able to walk on both legs," he says, "I just feel happy."

In electing Therdchai Jivacate to receive the 2008 Ramon Magsaysay Award for Public Service, the board of trustees recognizes his dedicated efforts in Thailand to provide inexpensive, practical, and comfortable artificial limbs to even the poorest amputees.