title: Evaluation of the effects of the Arm Light Exoskeleton on movement execution and muscle activities: a pilot study on healthy subjects.
abstract: BACKGROUND
  Exoskeletons for lower and upper extremities have been introduced in neurorehabilitation because they can guide the patient's limb following its anatomy, covering many degrees of freedom and most of its natural workspace, and allowing the control of the articular joints. The aims of this study were to evaluate the possible use of a novel exoskeleton, the Arm Light Exoskeleton (ALEx), for robot-aided neurorehabilitation and to investigate the effects of some rehabilitative strategies adopted in robot-assisted training.
  
  
  METHODS
  We studied movement execution and muscle activities of 16 upper limb muscles in six healthy subjects, focusing on end-effector and joint kinematics, muscle synergies, and spinal maps. The subjects performed three dimensional point-to-point reaching movements, without and with the exoskeleton in different assistive modalities and control strategies.
  
  
  RESULTS
  The results showed that ALEx supported the upper limb in all modalities and control strategies: it reduced the muscular activity of the shoulder's abductors and it increased the activity of the elbow flexors. The different assistive modalities favored kinematics and muscle coordination similar to natural movements, but the muscle activity during the movements assisted by the exoskeleton was reduced with respect to the movements actively performed by the subjects. Moreover, natural trajectories recorded from the movements actively performed by the subjects seemed to promote an activity of muscles and spinal circuitries more similar to the natural one.
  
  
  CONCLUSIONS
  The preliminary analysis on healthy subjects supported the use of ALEx for post-stroke upper limb robotic assisted rehabilitation, and it provided clues on the effects of different rehabilitative strategies on movement and muscle coordination.
authors.affiliation: Bertarelli Foundation Chair in Translational Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
authors.forename: Elvira
authors.initials: E
authors.lastname: Pirondini
authors.affiliation: Bertarelli Foundation Chair in Translational Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland. martina.coscia@epfl.ch.|Wyss Center for Bio-and Neuro- Engineering, Geneva, Switzerland. martina.coscia@epfl.ch.
authors.forename: Martina
authors.initials: M
authors.lastname: Coscia
authors.affiliation: PERceptual Robotics Laboratory, Scuola Superiore Sant'Anna, Pisa, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Marcheschi
authors.affiliation: PERceptual Robotics Laboratory, Scuola Superiore Sant'Anna, Pisa, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Roas
authors.affiliation: PERceptual Robotics Laboratory, Scuola Superiore Sant'Anna, Pisa, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Salsedo
authors.affiliation: PERceptual Robotics Laboratory, Scuola Superiore Sant'Anna, Pisa, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Frisoli
authors.affiliation: PERceptual Robotics Laboratory, Scuola Superiore Sant'Anna, Pisa, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Bergamasco
authors.affiliation: Bertarelli Foundation Chair in Translational Neuroengineering, Center for Neuroprosthetics and Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.|The Biorobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy.
authors.forename: Silvestro
authors.initials: S
authors.lastname: Micera
mesh_terms: D000328:Adult; D001132:Arm / Q000502:physiology*; D001696:Biomechanical Phenomena; D004576:Electromyography; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007596:Joints / Q000502:physiology; D008297:Male; D009068:Movement / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D010865:Pilot Projects; D011597:Psychomotor Performance / Q000502:physiology*; D012046:Rehabilitation / Q000295:instrumentation; D012371:Robotics; D012656:Self-Help Devices; D034941:Upper Extremity / Q000502:physiology; D055815:Young Adult