Some international scientists, when traveling to Vietnam, were curious about the Vietnamese bamboo pole.
Southeast Asia, with its rich rainforest and thousands of insects and mammals, is the place for a biologist to look for inspiration. But when scientist James Croft, of Edith Cowan University, Australia, traveled to Vietnam, what intrigued him was not the rich flora and fauna, but the fact that the villagers carried a large, double load. when more than their body weight, on “a bamboo pole over the shoulder” – the pole .
“I’m curious how the barbell has evolved,” says Croft. “I wonder if the flexion of the struts allows them to deliver more efficiently.” However, he also knew that the benefits of studying loads on curved struts yielded different conclusions; Some studies have shown that bent shoulder poles are beneficial, while others have not. Croft realized that many of the previous investigations had been done with beginners, while the villagers he observed were true experts, many with decades of experience.
The curved bamboo pole protects the shoulder of the bearer more.
After discussing the issue with scientist John Bertram from the University of Calgary, Canada, Mr. Croft decided to return to Vietnam to find out if experienced pole carriers have adapted to the way they are. walk to help them carry heavy loads or not. The team published their findings in the December 4 issue of the Journal of Experimental Biology that villagers carrying heavy loads on flexible bent poles can use 20 percent less energy than when using hard column.
“The trip to Vietnam was both exciting and challenging,” said Ryan Schroeder, also from the University of Calgary, recounting how the trio drove near China’s southern border after flying to Hanoi. “We contacted Thai Nguyen University of Medicine and Pharmacy and met two scientists Assoc., Dr. Nguyen Van Son and Dr. Hac Van Vinh. Then we hired an interpreter by connecting with people who have experience using bamboo poles,” said Schroeder.
After recruiting 14 volunteers, ranging in age from 18 to 80, the team asked them to walk along a 20-meter path carrying a load of 0% to 50% of their body weight on the bar. their burden. The researchers then measured the volunteers’ movements with accelerometers placed on their ankles, back and sides of the bar.
Back at the University of Calgary, Schroeder analyzed the volunteers’ movements and found that the villagers were adjusting their stride 3.3% (0.067 steps per second) when carrying half their body weight. they are on the pole. And when he built a computer simulation of walkers and calculated the contribution of bar flexibility to walking efficiency, he found that walkers moved with little effort. than when slightly deviating from the natural pitch of the struts.
The simulation also predicts that walkers carrying their own body weight on a bamboo pole will save almost 20% more energy than using a stiff pole. In addition, the bent bamboo pole provided more protection to their shoulders , by reducing the force on them by 18% when transporting half their body weight, and that allowed them to carry extremely heavy loads. travel for kilometers.
“It seems that we can learn a lot from rural people in Asia, who have been using bamboo poles to carry their burdens for hundreds, if not thousands, of years,” Schroeder said. year. He is also trying to use this principle in new backpack designs. “These simple but remarkable tools have the potential to reduce human effort to carry. Westerners are just beginning to catch up with this innovation,” he said with a smile.
Let’s look at the images of the dear bamboo poles that have existed for thousands of years on Vietnamese shoulders:
