title: Upper body balance control strategy during continuous 3D postural perturbation in young adults.
abstract: We explored how changes in vision and perturbation frequency impacted upright postural control in healthy adults exposed to continuous multiaxial support-surface perturbation. Ten subjects were asked to maintain equilibrium in standing stance with eyes open (EO) and eyes closed (EC) during sinusoidal 3D rotations at 0.25 (L) and 0.50 Hz (H). We measured upper-body kinematics--head, trunk, and pelvis--and analyzed differences in horizontal displacements and roll, pitch, and yaw sways. The presence of vision significantly decreased upper-body displacements in the horizontal plane, especially at the head level, while in EC the head was the most unstable segment. H trials produced a greater segment stabilization compared to L ones in EO and EC. Analysis of sways showed that in EO participants stabilized their posture by reducing the variability of trunk angles; in H trials a sway decrease for the examined segments was observed in the yaw plane and, for the pelvis only, in the pitch plane. Our results suggest that, during continuous multiaxial perturbations, visual information induced: (i) in L condition, a continuous reconfiguration of multi-body-segments orientation to follow the perturbation; (ii) in H condition, a compensation for the ongoing perturbation. These findings were not confirmed in EC where the same strategy--that is, the use of the pelvis as a reference frame for the body balance was adopted both in L and H.
authors.affiliation: Department of Mechanical and Aerospace Engineering, "Sapienza" University of Rome, Via Eudossiana, Rome 18 00184, Italy. Electronic address: valentinaamori@virgilio.it.
authors.forename: V
authors.initials: V
authors.lastname: Amori
authors.affiliation: Movement Analysis and Robotics Laboratory (MARLab), Neurorehabilitation Division, IRCCS Bambino Gesù Children's Hospital, Via Torre di Palidoro, Passoscuro (Fiumicino), Rome 00050, Italy. Electronic address: maurizio.petrarca@opbg.net.
authors.forename: M
authors.initials: M
authors.lastname: Petrarca
authors.affiliation: "Niccolò Cusano" University, Mechanical Engineering Faculty, Via Don Carlo Gnocchi, Rome 3 00166, Italy; Movement Analysis and Robotics Laboratory (MARLab), Neurorehabilitation Division, IRCCS Bambino Gesù Children's Hospital, Via Torre di Palidoro, Passoscuro (Fiumicino), Rome 00050, Italy. Electronic address: fabrizio.patane@unicusano.it.
authors.forename: F
authors.initials: F
authors.lastname: Patané
authors.affiliation: Movement Analysis and Robotics Laboratory (MARLab), Neurorehabilitation Division, IRCCS Bambino Gesù Children's Hospital, Via Torre di Palidoro, Passoscuro (Fiumicino), Rome 00050, Italy. Electronic address: enrico.castelli@opbg.net.
authors.forename: E
authors.initials: E
authors.lastname: Castelli
authors.affiliation: Department of Mechanical and Aerospace Engineering, "Sapienza" University of Rome, Via Eudossiana, Rome 18 00184, Italy; Movement Analysis and Robotics Laboratory (MARLab), Neurorehabilitation Division, IRCCS Bambino Gesù Children's Hospital, Via Torre di Palidoro, Passoscuro (Fiumicino), Rome 00050, Italy. Electronic address: paolo.cappa@uniroma1.it.
authors.forename: P
authors.initials: P
authors.lastname: Cappa
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D019416:Head Movements / Q000502:physiology; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology; D009949:Orientation; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology; D014785:Vision, Ocular / Q000502:physiology; D055815:Young Adult
keywords: Continuous multiaxial perturbation; Dynamic posturography; Perturbation frequency; Visual condition