Metabolic costs and muscle activity patterns during robotic- and therapist-assisted treadmill walking in individuals with incomplete spinal cord injury.
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.
Israel
Jeffrey F
JF
Department of Physical Therapy, University of Illinois at Chicago, Chicago, IL 60612, USA.
Campbell
Donielle D
DD
Kahn
Jennifer H
JH
Hornby
T George
TG
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*