title: Trunk control impairment is responsible for postural instability during quiet sitting in individuals with cervical spinal cord injury.
abstract: BACKGROUND
  Individuals with cervical spinal cord injury usually sustain impairments to the trunk and upper and lower limbs, resulting in compromised sitting balance. The objectives of this study were to: 1) compare postural control of individuals with cervical spinal cord injury and able-bodied individuals; and 2) investigate the effects of foot support and trunk fluctuations on postural control during sitting balance.
  
  
  METHODS
  Ten able-bodied individuals and six individuals with cervical spinal cord injury were asked to sit quietly during two 60s trials. The forces exerted on the seat and the foot support surfaces were measured separately using two force plates. The global centre of pressure sway was obtained from the measurements on the two force plates, and the sway for each force plate was calculated individually.
  
  
  RESULTS
  Individuals with spinal cord injury had at least twice as large global and seat sways compared to able-bodied individuals, while foot support sway was not significantly different between the two groups. Comparison between global and seat sways showed that anterior-posterior velocity of global sway was larger compared to the seat sway in both groups.
  
  
  CONCLUSIONS
  Postural control of individuals with cervical spinal cord injury was worse than that of able-bodied individuals. The trunk swayed more in individuals with spinal cord injury, while the stabilization effect of the feet did not differ between the groups. Foot support affected anterior-posterior fluctuations in both groups equally. Thus, trunk control is the dominant mechanism contributing to sitting balance in both able-bodied and spinal cord injury individuals.
authors: Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto M5S 3G9E, Ontario, Canada; Neural Engineering and Therapeutics Team, Lyndhurst Centre, Toronto Rehabilitation Institute,University Health Network, 520 Sutherland Drive, Toronto,M4G 3V9, Ontario, Canada. Electronic address: matija.milosevic@utoronto.ca.
authors: Matija
authors: M
authors: Milosevic
authors: Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto M5S 3G9E, Ontario, Canada; Neural Engineering and Therapeutics Team, Lyndhurst Centre, Toronto Rehabilitation Institute,University Health Network, 520 Sutherland Drive, Toronto,M4G 3V9, Ontario, Canada. Electronic address: k.masani@utoronto.ca.
authors: Kei
authors: K
authors: Masani
authors: Neural Engineering and Therapeutics Team, Lyndhurst Centre, Toronto Rehabilitation Institute,University Health Network, 520 Sutherland Drive, Toronto,M4G 3V9, Ontario, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, TorontoM5S 1A8, Ontario, Canada. Electronic address: m.kuipers@alum.utoronto.ca.
authors: Meredith J
authors: MJ
authors: Kuipers
authors: Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto M5S 3G9E, Ontario, Canada; Neural Engineering and Therapeutics Team, Lyndhurst Centre, Toronto Rehabilitation Institute,University Health Network, 520 Sutherland Drive, Toronto,M4G 3V9, Ontario, Canada. Electronic address: hossein.rouhani@utoronto.ca.
authors: Hossein
authors: H
authors: Rahouni
authors: Neural Engineering and Therapeutics Team, Lyndhurst Centre, Toronto Rehabilitation Institute,University Health Network, 520 Sutherland Drive, Toronto,M4G 3V9, Ontario, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, TorontoM5S 1A8, Ontario, Canada; Department of Physical Therapy, University of Toronto, 500 University Avenue, TorontoM5G 1V7, Ontario, Canada. Electronic address: m.verrier@utoronto.ca.
authors: Mary C
authors: MC
authors: Verrier
authors: Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto M5S 3G9E, Ontario, Canada; Neural Engineering and Therapeutics Team, Lyndhurst Centre, Toronto Rehabilitation Institute,University Health Network, 520 Sutherland Drive, Toronto,M4G 3V9, Ontario, Canada; Department of Electrical and Computer Engineering, Ryerson University, 350 Victoria Street, TorontoM5B 2K3, Ontario, Canada. Electronic address: kmcconvi@ee.ryerson.ca.
authors: Kristiina M V
authors: KM
authors: McConville
authors: Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto M5S 3G9E, Ontario, Canada; Neural Engineering and Therapeutics Team, Lyndhurst Centre, Toronto Rehabilitation Institute,University Health Network, 520 Sutherland Drive, Toronto,M4G 3V9, Ontario, Canada; Department of Physical Therapy, University of Toronto, 500 University Avenue, TorontoM5G 1V7, Ontario, Canada. Electronic address: milos.popovic@utoronto.ca.
authors: Milos R
authors: MR
authors: Popovic
mesh_terms: D000328:Adult; D000368:Aged; D066193:Cervical Cord / Q000293:injuries* / Q000503:physiopathology*; D005260:Female; D005528:Foot; D006801:Humans; D008297:Male; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology*; D011312:Pressure; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D060726:Torso / Q000503:physiopathology*
keywords: Centre of pressure (COP); Foot support; Postural sway; Sitting balance; Spinal cord injury (SCI); Trunk control