title: Metabolic costs and muscle activity patterns during robotic- and therapist-assisted treadmill walking in individuals with incomplete spinal cord injury.
abstract: OBJECTIVE
  Robotic devices that provide passive guidance and stabilization of the legs and trunk during treadmill stepping may increase the delivery of locomotor training to subjects with neurological injury. Lower-extremity guidance also may reduce voluntary muscle activity as compared with compliant assistance provided by therapists. The purpose of this study was to investigate differences in metabolic costs and lower-limb muscle activity patterns during robotic- and therapist-assisted treadmill walking.
  
  
  METHODS
  Twelve ambulatory subjects with motor incomplete spinal cord injury participated.
  
  
  METHODS
  In 2 separate protocols, metabolic and electromyographic (EMG) data were collected during standing and stepping on a treadmill with therapist and robotic assistance. During robotic-assisted walking, subjects were asked to match the kinematic trajectories of the device and maximize their effort. During therapist-assisted walking, subjects walked on the treadmill with manual assistance provided as necessary.
  
  
  RESULTS
  Metabolic costs and swing-phase hip flexor EMG activity were significantly lower when subjects were asked to match the robotic device trajectories than with therapist-assisted walking. These differences were reduced when subjects were asked to maximize their effort during robotic-assisted stepping, although swing-phase plantar-flexor EMG activity was increased. In addition, during standing prior to therapist- or robotic-assisted stepping, metabolic costs were higher without stabilization from the robotic device.
  
  
  CONCLUSIONS
  Differences in metabolic costs and muscle activity patterns between therapist- and robotic-assisted standing and stepping illustrate the importance of minimizing passive guidance and stabilization provided during step training protocols.
authors.affiliation: Department of Physical Therapy, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: Jeffrey F
authors.initials: JF
authors.lastname: Israel
authors.forename: Donielle D
authors.initials: DD
authors.lastname: Campbell
authors.forename: Jennifer H
authors.initials: JH
authors.lastname: Kahn
authors.forename: T George
authors.initials: TG
authors.lastname: Hornby
mesh_terms: D000293:Adolescent; D000328:Adult; D001676:Biofeedback, Psychology; D002985:Clinical Protocols; D004576:Electromyography; D005080:Exercise Test / Q000379:methods; D005081:Exercise Therapy / Q000379:methods; D005684:Gait; D006801:Humans; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology; D009989:Orthotic Devices; D012371:Robotics / Q000379:methods; D013119:Spinal Cord Injuries / Q000145:classification / Q000378:metabolism / Q000503:physiopathology / Q000534:rehabilitation*; D016138:Walking / Q000502:physiology*