From Earth to Orbit : influence of graviceptive inputs on reach and grip behavior
(2025)
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Thesis_SV_final_print.pdf
Embargo from 2027-06-30 - Adobe PDF
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Details
- Authors
- Supervisors
- Lefèvre, Philippe
- Abstract
- Gravity has long been proposed to play a unique role in sensorimotor coordination, either as a driving force used by the motor system to minimize energy expenditure or as an external cue for spatial orientation. Investigating the impact of gravity on daily-life activities such as object manipulation, an essential skill for the success of future space missions, has so far been limited to short-term exposure to weightlessness during parabolic flights. It therefore remained unknown whether or how the brain adapts to long-term exposure to weightlessness as experienced by astronauts on the ISS. In this thesis, we study the kinematics of arm movements and the dynamics of finger forces in participants exposed to weightless environments or to tilted postures while manipulating objects. We first explore the sensorimotor coordination of astronauts before, during, and after their mission onboard the ISS. We then study, on Earth, the influence of body tilt with respect to gravity and test if the upright posture, by virtue of being at a biomechanical singularity induced by the force of gravity, represents a unique condition in which sensorimotor coordination is the most stable. Finally, we investigate the contributions of gravitational and biomechanical effects to kinematics features of reaching movements along the vertical and horizontal axes on the ground and in space. Numerical simulations based on optimal control models considering the nonlinear arm dynamics show that velocity profiles are shaped by both effects and quickly adapt to environmental dynamics. These studies contribute to a better understanding of the role played by graviceptive inputs in object manipulation.
- Affiliations
UCLouvain SST/ICTM/INMA - Pôle en ingénierie mathématique UCLouvain SSS/IONS/COSY - Systems & cognitive Neuroscience
Citations
Vandergooten, S. (2025). From Earth to Orbit : influence of graviceptive inputs on reach and grip behavior.