For astronauts, being in outer space means adapting everyday tasks to a weightless environment. Once they return to earth, astronauts may find that they not only struggle to perform these same tasks, but they also face an increased risk of back pain and injury.
“Astronauts have a significant problem with disabling low back pain in space, and a high risk of disc herniation when they return to Earth,” explains Britta Berg-Johansen, who recently presented her research at the Annual Meeting of the Orthopaedic Research Society (ORS). “This is not only a dilemma for crew safety, but also for NASA’s plans for future long duration space travel.” Berg-Johansen and her team of researchers have been exploring mechanisms of the increased rates of disc herniation that astronauts experience. “Without gravity loading, spinal discs swell, trunk muscles atrophy, and vertebrae become osteoporotic. This creates a triple jeopardy for astronauts and a major hurdle for future long-duration space travel, such as planned missions to Mars”
Researchers from the UC San Francisco Orthopaedic Bioengineering Laboratory have been working with mouse tails that were obtained through a NASA tissue sharing program. Having returned from a 30 day space mission, the mice exhibited reduced spine bending strength and flexibility as well as significant bone loss compared to mice in the control group. How does this relate to men and women in space? “Our research indicates that bone loss and spinal stiffening during spaceflight may contribute to the increased herniation risk in astronauts. This motivates the development of countermeasures related to maintaining spine posture and flexibility as well as monitoring and preventing bone loss during spaceflight and limiting heavy lifting activities upon returning to Earth.”
The next step for the team is to further investigate the contributions of bone loss, disc stiffening, and other tissue differences such as muscle atrophy toward disc herniation risk in human spines. “Our hope,” says Berg-Johansen, “is that our data will have importance for improving rehabilitation protocols such as avoiding heavy lifting activities and excessive spinal movements as astronauts acclimate to gravity after returning to Earth.”
Founded in 1954, the Orthopaedic Research Society strives to be the world’s leading forum for the dissemination of new musculoskeletal research findings. The musculoskeletal system provides form, support, stability, and movement to the body.
