Movement in low gravity environments (MoLo) programme–The MoLo-L.O.O.P. study protocol

Abstract

Background Exposure to prolonged periods in microgravity is associated with deconditioning of the musculoskeletal system due to chronic changes in mechanical stimulation. Given astronauts will operate on the Lunar surface for extended periods of time, it is critical to quantify both external (e.g., ground reaction forces) and internal (e.g., joint reaction forces) loads of relevant movements performed during Lunar missions. Such knowledge is key to predict musculoskeletal deconditioning and determine appropriate exercise countermeasures associated with extended exposure to hypogravity. Objectives The aim of this paper is to define an experimental protocol and methodology suitable to estimate in high-fidelity hypogravity conditions the lower limb internal joint reaction forces. State-of-the-art movement kinetics, kinematics, muscle activation and muscle-tendon unit behaviour during locomotor and plyometric movements will be collected and used as inputs (Objective 1), with musculoskeletal modelling and an optimisation framework used to estimate lower limb internal joint loading (Objective 2). Methods Twenty-six healthy participants will be recruited for this cross-sectional study. Participants will walk, skip and run, at speeds ranging between 0.56–3.6 m/s, and perform plyometric movement trials at each gravity level (1, 0.7, 0.5, 0.38, 0.27 and 0.16g) in a randomized order. Through the collection of state-of-the-art kinetics, kinematics, muscle activation and muscle-tendon behaviour, a musculoskeletal modelling framework will be used to estimate lower limb joint reaction forces via tracking simulations. Conclusion The results of this study will provide first estimations of internal musculoskeletal loads associated with human movement performed in a range of hypogravity levels. Thus, our unique data will be a key step towards modelling the musculoskeletal deconditioning associated with long term habitation on the Lunar surface, and thereby aiding the design of Lunar exercise countermeasures and mitigation strategies.

A novel computational framework for the estimation of internal musculoskeletal loading and muscle adaptation in hypogravity

“…This approach has been employed previously allowing for exercise prescription to be personalised relative to patient injury and rehabilitation stage ( Van Rossom et al, 2018 ). In a hypogravity context, this research effort is already underway ( Herssens et al, 2022 ) and would allow training interventions to be assessed with further research (e.g., with randomised control trials), and for practitioners to use to supplement their expert knowledge when designing astronaut exercise programs. It is acknowledged that providing well validated tools is another barrier to overcome in the implementation of MSK modelling in practice ( Fregly, 2021 ).…”

Horizontal running inside circular walls of Moon settlements: a comprehensive countermeasure for low-gravity deconditioning?

“…On a different day, the same participants ran on a treadmill (PPS 55Ortho, Woodway) at 1 g , and at 0.8 g , 0.5 g and 0.17 g with a vertical body weight suspension device (LOOP laboratory, ESA Ground-Based Facility for Research in Low Gravity Locomotion, University of Milan) [ 18 , 32 ] at the maximal speed reachable (and held for 10 s) at those gravity levels. Also, the male participant ran (at 1 g ) at 6.69 m s −1 along a 40-m hallway equipped with five 3D force platforms (Bertec, USA).…”