The aim of the GRIP experiment is to investigate how gravity impacts the kinematics and dynamics of the upper limb during dexterous manipulation of objects and how the central nervous system adapts to long-term exposure to microgravity and subsequently back to Earth gravity. Hence, we proposed to conduct a set of experiments on healthy human subjects, involving the manipulation of an instrumented object during exposure to normal and microgravity, and to study how the central nervous system adapts motor control in order to cope with the new physical environment. More particularly, the coordination between the grasping force (or grip force, GF) and the load force (LF) is studied, as well as the adaptation of the movement dynamics and kinematics and the interaction between cognitive and sensory cues that establish a reference frame for the human brain. Here we describe the background motivation, the parabolic flight tests that initiated the scientific hypotheses and the technical and scientific process that led to the implementation of the GRIP experiment currently on board the International Space Station (ISS).
Part of the book: Preparation of Space Experiments