title: Afferent electrical stimulation during cycling improves spinal processing of sensorimotor function after incomplete spinal cord injury.
abstract: OBJECTIVE
  Appropriate afferent feedback delivery during the execution of motor tasks is important for rehabilitation after incomplete spinal cord injury (iSCI). However, during leg-cycling therapy, the plantar afferent feedback is minimal. We hypothesize that the augmentation of sensory input by combining cycling with a locomotor-like stimulation of plantar cutaneous innervations (ES-cycling), might help to restore proper spinal processing of sensorimotor function.
  
  
  METHODS
  Thirteen non-injured subjects and 10 subjects with iSCI performed 10 minutes of cycling and, on another session, of ES-cycling. To assess spinal processing of sensorimotor function, soleus H-reflex response was tested following a conditioning plantar electrical stimulation applied at 25-100 ms inter-stimulus intervals (ISI's), measured before and after the execution of the tasks.
  
  
  RESULTS
  Before tasks execution, the conditioned H-reflex response was modulated in non-injured subjects, and absent in subjects with iSCI; after cycling, modulation profiles were unchanged. However, after ES-cycling a significant increase in H-reflex excitability was observed in the non-injured group at 100 ms ISI (p < 0.05), and in the iSCI group between 50-75 ms ISI (p < 0.001).
  
  
  CONCLUSIONS
  The loss of reflex modulation in subjects with iSCI suggests reduced spinal processing of sensorimotor function. Reflex modulation recovery after ES-cycling may indicate the partial reactivation of these mechanisms.
authors.affiliation: Neural Rehabilitation Group, Cajal Institute, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
authors.forename: Stefano
authors.initials: S
authors.lastname: Piazza
authors.affiliation: Sensorimotor Function Group, Hospital Nacional de Parapléjicos, Toledo, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Serrano-Muñoz
authors.affiliation: Sensorimotor Function Group, Hospital Nacional de Parapléjicos, Toledo, Spain.|Toledo Physiotherapy Research Group, Nursing and Physiotherapy School, Castilla La Mancha University, Toledo, Spain.
authors.forename: Julio
authors.initials: J
authors.lastname: Gómez-Soriano
authors.affiliation: Neural Rehabilitation Group, Cajal Institute, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Torricelli
authors.affiliation: Health Sciences Institute, Consejería de Sanidad, Talavera de la Reina, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Segura-Fragosa
authors.affiliation: Neural Rehabilitation Group, Cajal Institute, Consejo Superior de Investigaciones Científicas, Madrid, Spain.|Tecnológico de Monterrey, Mexico.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Pons
authors.affiliation: Sensorimotor Function Group, Hospital Nacional de Parapléjicos, Toledo, Spain.|Stoke Mandeville Spinal Research, National Spinal Injuries Centre, Aylesbury, UK.|Harris Manchester College, University of Oxford, Oxford, UK.
authors.forename: Julian
authors.initials: J
authors.lastname: Taylor
mesh_terms: D000328:Adult; D000344:Afferent Pathways / Q000502:physiology; D000368:Aged; D001642:Bicycling / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006181:H-Reflex / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology; D011597:Psychomotor Performance / Q000502:physiology*; D013116:Spinal Cord / Q000503:physiopathology; D013119:Spinal Cord Injuries / Q000503:physiopathology* / Q000534:rehabilitation*; D055815:Young Adult
keywords: Spinal cord injury; afferent feedback; leg-cycling; sensorimotor processing; soleus H-reflex