Although the team originally thought that wearing a prosthesis in space may not be necessary, tests have shown it is likely to prove crucial for maintaining good fitness, balance, and for being able to evacuate quickly in an emergency.
But making sure it is safe and continues to fit correctly in microgravity is proving challenging. Astronauts’ bodies change in space because of microgravity, meaning Mr McFall’s legs could shrink or expand, and his prosthetic no longer fit.
To determine what might happen in space, he is undergoing experiments in Cologne on tilt tables in which he is tipped at an angle with his head lower than his feet, to mimic the effect of fluid rising up the body in microgravity.
“Most of the evidence so far suggests that fluid shifts up to your centre up to your trunk, and actually you lose some volume from a fluid point of view and your lower limbs,” he said.
“But we just need to prove that because a reduction in stump volume is easier to manage by padding it out a little bit with some extra material, but with an increase in stump volume you would need to make a socket that actually gets bigger.
“The commonest question I get asked is ‘do you need legs in space?’ and for floating around, maybe not necessarily, but it is useful in stabilising yourself so that you free up your hands for experiments.
“But we’ve found out I would need to wear a prosthesis on orbit to undertake the exercise countermeasures to maintain bone density and muscle mass.”
Mr McFall, 43, who was born in Surrey and grew up in Somerset, had his right leg amputated when he was 19 after a motorbike accident. But after learning to run again, he became a professional athlete, winning bronze in the 2008 Beijing Paralympics in the 100 metres T42 event.
Dr. Thomas Hughes is a UK-based scientist and science communicator who makes complex topics accessible to readers. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
