Trunk muscle activation in a person with clinically complete thoracic spinal cord injury.
OBJECTIVE
The aim of this study was to assess if, and how, upper body muscles are activated in a person with high thoracic spinal cord injury, clinically classified as complete, during maximal voluntary contractions and in response to balance perturbations.


METHODS
Data from one person with spinal cord injury (T3 level) and one able-bodied person were recorded with electromyography from 4 abdominal muscles using indwelling fine-wire electrodes and from erector spinae and 3 upper trunk muscles with surface electrodes. Balance perturbations were carried out as forward or backward support surface translations.


RESULTS
The person with spinal cord injury was able to activate all trunk muscles, even those below the injury level, both in voluntary efforts and in reaction to balance perturbations. Trunk movements were qualitatively similar in both participants, but the pattern and timing of muscle responses differed: upper trunk muscle involvement and occurrence of co-activation of ventral and dorsal muscles were more frequent in the person with spinal cord injury.


CONCLUSIONS
These findings prompt further investigation into trunk muscle function in paraplegics, and highlight the importance of including motor tests for trunk muscles in persons with thoracic spinal cord injury, in relation to injury classification, prognosis and rehabilitation.
Biomechanics and Motor Control Laboratory, Department of Neuroscience, arolinska Institutet, and the Swedish School of Sport and Health Sciences (GIH), Box 5626, SE-11486 Stockholm, Sweden. anna.bjerkefors@gih.se
Anna
A
Bjerkefors
Mark G
MG
Carpenter
Andrew G
AG
Cresswell
Alf
A
Thorstensson
D000009:Abdominal Muscles / Q000503:physiopathology; D000328:Adult; D004599:Electric Stimulation Therapy; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010264:Paraplegia / Q000503:physiopathology; D004856:Postural Balance / Q000502:physiology; D013119:Spinal Cord Injuries / Q000503:physiopathology / Q000534:rehabilitation*; D013904:Thoracic Vertebrae / Q000503:physiopathology