CALGARY, ALBERTA-- When the world was captivated by grainy images of Neil Armstrong bounding across the moon, they did not realize Armstrong's leaps probably had more to do with how his space suit was designed than walking in low gravity.
Scientists have discovered that astronauts likely can walk on the moon - at speeds which it had been thought they would become airborne. They believe this is due to the forces generated by their swinging arms and legs, which help them to remain attached to the moon's surface.
University of Calgary Faculty of Kinesiology's Brent Edwards and John De Witt, a researcher with Wyle Science, Engineering and Technology, have published these findings in the most recent edition of The Journal of Experimental Biology.
"The ultimate reason that we were looking at what speeds humans walk and at what speed they choose to transition to a run in lunar gravity, is because it has implications for new space suit design," says Edwards, who was the second author on the paper. "You need to understand the energetics of locomotion. Whether they're walking or running, can have big implications on the amount of energy they're expending. Also if the astronauts need to run, there needs to be a much wider range of motion in the hip, back, and knee and things like that."
Edwards, who is a musculoskeletal bio-mechanist, examines the influence of mechanical loading on musculoskeletal health and says that the biggest reason Apollo astronauts didn't just walk on the moon was likely due to the design of early space suits, "You really don't see a huge range of motion in those space suits," says Edwards. "Some people hypothesize that that's why you don't see them running around. That's why you see them sort of loping and bouncing from place to place because there's no knee joint in the space suit."
Naturally, the people most interested in designing new spacesuits are NASA. Michael Gernhardt, head of NASA's Extravehicular Activity Physiology, Systems and Performance Project, wanted to learn more about how humans move in low gravity, with the ultimate goal of designing a modern space suit that permits freer movement.
Flying to the moon isn't exactly an option, so the researchers went up in NASA's adapted DC-9 aircraft - which reduces the gravity on board by performing swooping parabolic flights. Each stage of the flight produces different gravities, including about 20 seconds that mimics gravity on the moon. Of course such flights aren't particularly pleasant, although Edwards, who went on several of the missions, says he was never ill. "They pump you full of drugs. Lots of motion-sickness drugs, and then amphetamine-type drugs that counteract the drowsiness from the motion-sickness drugs... I did see a few people get sick, but luckily I never got sick!"
Besides space suit design, Edwards says the research has some practical applications for Earth, including confirmation that using a harness system to suspend five-sixths of a runner's weight provides an adequate simulation of lunar gravity. This might help to create new neuro-muscular therapies that would reduce risk of falling injuries for patients with balance issues. The research also might lead to a better understanding of how mechanical loading could help stimulate bones and muscles to create stronger integrity. Finally the research may help in the design of exercise counter-measures designed to prevent future generations of space travellers from suffering too much bone and muscle loss.
Note: Edwards is available to speak with reporters today from 10 am to noon. You can also call to arrange interviews at another time.
About the University of Calgary
The University of Calgary is a leading Canadian university located in the nation's most enterprising city. The university has a clear strategic direction to become one of Canada's top five research universities by 2016, where research and innovative teaching go hand in hand, and where we fully engage the communities we both serve and lead. This strategy is called Eyes High, inspired by the university's Gaelic motto, which translates as 'I will lift up my eyes.'
Don McSwiney, University of Calgary
