Vibration elicits involuntary, step-like behavior in individuals with spinal cord injury.
BACKGROUND
Impaired walking is a debilitating consequence of spinal cord injury (SCI). This impairment arises, to some degree, from disruption of supraspinal pathways that activate the spinal locomotor central pattern generator (CPG). Evidence in nondisabled (ND) individuals suggests that vibration activates locomotor CPGs, eliciting involuntary step-like behavior.


OBJECTIVE
To compare vibration-elicited step-like behavior in individuals with chronic SCIs with the responses of ND individuals and to assess the influence of locomotor training on these responses.


METHODS
Participants included 7 individuals with motor-incomplete SCIs (MISCIs) and 6 with motor-complete SCIs (MCSCIs) who were untrained, 6 individuals with MISCIs who underwent locomotor training, and 8 ND individuals. Kinematic and EMG data were collected while vibration was applied to the quadriceps, hamstrings, or tensor fascia latae (TFL) muscles. Consistency and robustness of vibration-elicited responses was determined from hip and knee angle data.


RESULTS
Consistent and reliable step-like behaviors were elicited in individuals with MISCIs and MCSCIs, although responses were not as robust as those in ND individuals. Vibration to the TFL elicited the most robust responses. Consistency and robustness were not influenced by SCI severity or locomotor training but appeared to increase with repeated testing.


CONCLUSIONS
These results confirm that vibration elicits step-like behaviors in individuals with SCIs, even those with no voluntary motor function in the legs. Further research is warranted to investigate the use of vibration as an approach to activating the spinal CPGs associated with stepping, perhaps as an adjunct to locomotor training for individuals with SCIs.
The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA. edee@miami.edu
Edelle
E
Field-Fote
Lanitia L
LL
Ness
Michele
M
Ionno
D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena / Q000502:physiology; D004576:Electromyography; D005081:Exercise Therapy / Q000295:instrumentation / Q000379:methods*; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D013119:Spinal Cord Injuries / Q000145:classification / Q000150:complications / Q000534:rehabilitation*; D014732:Vibration / Q000627:therapeutic use*; D055815:Young Adult