Optimising prostheses for para-long jump athletes
When Élodie Doyen decided to start a doctorate, she naturally turned towards physics applied to sport, a field she is passionate about. She quickly realised that her training as a general engineer, with a component in biomechanics and sensory engineering, could be put to good use in parasports and benefit para-athletes. Her doctorate, prepared at the Institut Polytechnique de Paris, and within the Institut des Sciences de la Mécanique et Applications Industrielles (IMSIA*), involved optimising tibial prostheses (i.e. for people who had a leg amputation in the area of the tibia), to enable paralympic athletes practising long jumping to jump further, while minimising the risk of injury. She defended her thesis on 27 April 2023.
With the Paris Olympic and Paralympic Games coming soon, this project is part of Science2024, a collective research programme dedicated to supporting athletes, mainly through physics, mechanics, and mathematics. As part of her thesis, Élodie Doyen worked with long-jump athletes who are tibia amputees, and in particular Dimitri Pavadé, paralympic vice-champion at the 2020 Tokyo Games. These athletes use a prosthesis made up of three parts: a socket by which the prosthesis is attached to the amputated limb, a carbon fibre blade, and a sole that hits the ground during strides.
Élodie Doyen's research involved optimising two elements of the prosthesis: the sole to increase jumping performance, and the socket to improve athlete comfort and reduce the risk of associated injuries. To optimise the sole, she worked on absorbing the vibrations and shocks of the jump, and on the shape of the sole to help athletes tip the prosthesis more effectively with each stride. To improve the fit of the prosthesis, Élodie Doyen developed a method for measuring the pressure exerted on the stump, without impeding the athlete's movement. The measurement is carried out by placing sensors in the liner, a silicone part that fits between the stump and the socket. Based on this data and with the help of prosthetists, the shape of the socket could then be adapted to the morphology of each athlete.
"This measurement tool will eventually be useful to all lower-limb amputees, regardless of whether they are involved in high-level sport," she explains.
From sports physics to comics...
As well as building the technologies of tomorrow, Élodie Doyen is helping to disseminate scientific knowledge. At the end of 2022, while in her third year of doctoral studies, she decided to apply to have her thesis published as a comic strip in the book "Sciences en Bulles", an annual initiative of the French Ministry of Higher Education and Research, in partnership with the Syndicat national de l'édition. Her application was selected as one of the ten doctoral subjects in the book, which this year focuses on science and sport, also the theme of the Fête de la Science 2023 (a national science festival in France). In addition to writing her manuscript, she worked on formulating her research in terms that would be accessible to the general public, so that it could be adapted into a comic by documentary comic book author Héloïse Chochois.
"I wanted to get involved in a project to popularise science. I like being able to make scientific knowledge accessible, for example through analogies" says the young doctor, who is now looking for new scientific projects applied to sport, and who also wants to continue sharing science.
Cover and drawing by Héloïse Chochois from the book "Sciences en Bulles : Science et Sport", in which Élodie Doyen's thesis is adapted into a comic.
The Fête de la Science will be held throughout France from 6 to 16 October 2023. Élodie Doyen will present her thesis and her Sciences en Bulles experience on 14 October 2023 from 15:00 to 16:00 during the Fête de la Science on the campus of the Institut Polytechnique de Paris, with an exhibition and book signing. The "Sciences en Bulles" book will also be offered by the initiative's partner bookshops for the purchase of selected science books.