title: Human locomotion under reduced gravity conditions: biomechanical and neurophysiological considerations.
abstract: Reduced gravity offers unique opportunities to study motor behavior. This paper aims at providing a review on current issues of the known tools and techniques used for hypogravity simulation and their effects on human locomotion. Walking and running rely on the limb oscillatory mechanics, and one way to change its dynamic properties is to modify the level of gravity. Gravity has a strong effect on the optimal rate of limb oscillations, optimal walking speed, and muscle activity patterns, and gait transitions occur smoothly and at slower speeds at lower gravity levels. Altered center of mass movements and interplay between stance and swing leg dynamics may challenge new forms of locomotion in a heterogravity environment. Furthermore, observations in the lack of gravity effects help to reveal the intrinsic properties of locomotor pattern generators and make evident facilitation of nonvoluntary limb stepping. In view of that, space neurosciences research has participated in the development of new technologies that can be used as an effective tool for gait rehabilitation.
authors.affiliation: Centre of Space Bio-Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy ; Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Via Ardeatina 306, 00179 Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Sylos-Labini
authors.affiliation: Centre of Space Bio-Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy ; Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Via Ardeatina 306, 00179 Rome, Italy ; Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy.
authors.forename: Francesco
authors.identifier: 0000-0002-5360-6490
authors.initials: F
authors.lastname: Lacquaniti
authors.affiliation: Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Via Ardeatina 306, 00179 Rome, Italy.
authors.forename: Yuri P
authors.initials: YP
authors.lastname: Ivanenko
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D005684:Gait / Q000502:physiology; D006801:Humans; D018472:Hypogravity; D007866:Leg / Q000502:physiology*; D008124:Locomotion / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009929:Organ Size / Q000502:physiology