title: EMG patterns during assisted walking in the exoskeleton.
abstract: Neuroprosthetic technology and robotic exoskeletons are being developed to facilitate stepping, reduce muscle efforts, and promote motor recovery. Nevertheless, the guidance forces of an exoskeleton may influence the sensory inputs, sensorimotor interactions and resulting muscle activity patterns during stepping. The aim of this study was to report the muscle activation patterns in a sample of intact and injured subjects while walking with a robotic exoskeleton and, in particular, to quantify the level of muscle activity during assisted gait. We recorded electromyographic (EMG) activity of different leg and arm muscles during overground walking in an exoskeleton in six healthy individuals and four spinal cord injury (SCI) participants. In SCI patients, EMG activity of the upper limb muscles was augmented while activation of leg muscles was typically small. Contrary to our expectations, however, in neurologically intact subjects, EMG activity of leg muscles was similar or even larger during exoskeleton-assisted walking compared to normal overground walking. In addition, significant variations in the EMG waveforms were found across different walking conditions. The most variable pattern was observed in the hamstring muscles. Overall, the results are consistent with a non-linear reorganization of the locomotor output when using the robotic stepping devices. The findings may contribute to our understanding of human-machine interactions and adaptation of locomotor activity patterns.
authors: Laboratory of Neuromotor Physiology, Santa Lucia Foundation Rome, Italy ; Centre of Space Bio-medicine, University of Rome Tor Vergata Rome, Italy.
authors: Francesca
authors: F
authors: Sylos-Labini
authors: Laboratory of Neuromotor Physiology, Santa Lucia Foundation Rome, Italy ; Centre of Space Bio-medicine, University of Rome Tor Vergata Rome, Italy.
authors: Valentina
authors: V
authors: La Scaleia
authors: Laboratory of Neuromotor Physiology, Santa Lucia Foundation Rome, Italy.
authors: Andrea
authors: A
authors: d'Avella
authors: Spinal Cord Rehab Unit and CaRMA Lab, Santa Lucia Foundation Rome, Italy.
authors: Iolanda
authors: I
authors: Pisotta
authors: Spinal Cord Rehab Unit and CaRMA Lab, Santa Lucia Foundation Rome, Italy.
authors: Federica
authors: F
authors: Tamburella
authors: Spinal Cord Rehab Unit and CaRMA Lab, Santa Lucia Foundation Rome, Italy.
authors: Giorgio
authors: G
authors: Scivoletto
authors: Spinal Cord Rehab Unit and CaRMA Lab, Santa Lucia Foundation Rome, Italy.
authors: Marco
authors: M
authors: Molinari
authors: Biomechanical Engineering, Delft University of Technology Delft, Netherlands.
authors: Shiqian
authors: S
authors: Wang
authors: Biomechanical Engineering, University of Twente Enschede, Netherlands.
authors: Letian
authors: L
authors: Wang
authors: Biomechanical Engineering, University of Twente Enschede, Netherlands.
authors: Edwin
authors: E
authors: van Asseldonk
authors: Biomechanical Engineering, Delft University of Technology Delft, Netherlands ; Biomechanical Engineering, University of Twente Enschede, Netherlands.
authors: Herman
authors: H
authors: van der Kooij
authors: Laboratory of Neurophysiology and Movement Biomechanics, Université Libre de Bruxelles Brussels, Belgium.
authors: Thomas
authors: T
authors: Hoellinger
authors: Laboratory of Neurophysiology and Movement Biomechanics, Université Libre de Bruxelles Brussels, Belgium.
authors: Guy
authors: G
authors: Cheron
authors: OSSUR Reykjavík, Iceland.
authors: Freygardur
authors: F
authors: Thorsteinsson
authors: Space Applications Services N.V./S.A. Zaventem, Belgium.
authors: Michel
authors: M
authors: Ilzkovitz
authors: Space Applications Services N.V./S.A. Zaventem, Belgium.
authors: Jeremi
authors: J
authors: Gancet
authors: ANT Neuro Berlin, Germany.
authors: Ralf
authors: R
authors: Hauffe
authors: ANT Neuro Berlin, Germany.
authors: Frank
authors: F
authors: Zanov
authors: Laboratory of Neuromotor Physiology, Santa Lucia Foundation Rome, Italy ; Centre of Space Bio-medicine, University of Rome Tor Vergata Rome, Italy ; Department of Systems Medicine, University of Rome Tor Vergata Rome, Italy.
authors: Francesco
authors: F
authors: Lacquaniti
authors: Laboratory of Neuromotor Physiology, Santa Lucia Foundation Rome, Italy.
authors: Yuri P
authors: YP
authors: Ivanenko
keywords: EMG patterns; assisted gait; neuroprosthetic technology; robotic exoskeleton; spinal cord injury