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Updated: Mar 7, 2026
Paradigms of Lower Extremity Electrical Stimulation Training After Spinal Cord Injury
Published on: February 1, 2018
Afferent electrical stimulation during cycling improves spinal processing of sensorimotor function after incomplete
Stefano Piazza1, Diego Serrano-Muñoz2, Julio Gómez-Soriano2,3
1Neural Rehabilitation Group, Cajal Institute, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
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).
Conclusion:
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.
