From 2020 to 2023, Élodie Doyen conducted a thesis on the dynamic behavior of a tibial prosthesis for long jumping. Maximizing jumping performance, minimizing the risk of injury: for three years, she worked closely with these athletes who also have "that little something extra", the fortitude and determination that enable them to overcome their handicap and transform it into strength. It has given her a deep respect for these men and women who could have been overwhelmed by an accident or deformity, but who have decided to rise to the challenge at the highest level.
" Over and above the scientific results, this thesis has also been a wonderful human experience for me, in contact with top-level athletes like Dimitri Pavadé, whose difficulties and motivations I have come to understand. So much so that today, I' m more passionate about the Paralympics than the Olympics, because I fully understand the reasons behind the different categories, and the immense merit of para-athletes. Considering the difficulties they face, they actually achieve far more impressive feats than the able-bodied."
Nothing predestined Élodie Doyen for this realization, apart from the chance encounters she made along the way. During her engineering studies at ENISE in Saint-Étienne, she chose to specialize in "sensory engineering".
" I would define this field as mechanics applied to objects that come into contact with the human body. So it covers a very broad spectrum, with courses in anatomy, human-machine interface, home automation, and the physiology of tactile and visual perception, all really fascinating fields."
Applied to sport, this sensory engineering naturally concerns all sports equipment, which must function in symbiosis with the different parts of the body they come into contact with. For her final year internship, Élodie Doyen joined SportsLab, Decathlon's research center in Villeneuve d'Ascq.
"The aim of my research was to rationalize the tactile and visual perception of textiles, in order to develop objective and automatic methods of evaluation by comparison with a panel of users. It immediately fascinated me and made me want to pursue research in the field of sports. "
It just so happened that a friend of Élodie's, herself already doing a thesis in biomechanics, saw an advertisement for a thesis on the improvement of a jumping prosthesis. Élodie Doyen applied and was selected after an interview with her two co-supervisors, Jean-François Semblat and Fabien Szmytka, from the Mechanics Unit at ENSTA Paris.
" I was very lucky to do my thesis with this ENSTA Paris team. Communication with my thesis supervisors was very fluid, and they were always there for me when I had questions about the progress of my research. Now, a PhD isn't for everyone, because it's an intense 3-year commitment, in a field that's bound to be uncharted, with its share of doubts and questioning. You have to be motivated and really enjoy doing research.
Élodie Doyen's thesis aimed to optimize a jumping blade to improve long jump performance and reduce the risk of injury for para-athletes fitted with a tibial prosthesis.
"There's a compromise to be found between the rigidity of the prosthesis, which enables the athlete to retain good sensations and good feedback from the ground, and comfort, so as not to risk injury. Of course, we can't take the risk of having the athlete try out all the options, which is why I developed a test bench to measure the pressures in the prosthesis and test a wide range of parameters".
This work also led Élodie Doyen to publish a scientific article in Nature Scientific Reports on the characterization of mechanical interactions between the ground and a tibial prosthesis.
After defending her thesis in April 2023, the young doctor became a research engineer at ENSTA Paris.
" I'm continuing to work on reducing the risk of injury to prosthesis wearers, not just for athletes, but for all wearers of lower-limb devices. More than 35 million people worldwide have had at least one lower limb amputated, and need prostheses to move around independently. So this is research with a potentially huge impact on the lives of millions of people. It'san idea that motivates me, and a job that I really enjoy. "