Objective:

To compare changes in motor and autonomic function attributable to trans-spinal electrical stimulation (ts-ES) in individuals with incomplete spinal cord injury following 4 weeks of individualized locomotor treadmill training augmented with step-cycle-based peripheral nerve stimulation (PNS) and functional electrical muscle stimulation (FES) with and without ts-ES.

Background:

Spinal cord injury (SCI) is a central nervous system injury that often leads to motor, sensory and autonomic dysfunction. Non-invasive ts-ES has been shown to activate neural networks below the injury and improve motor function recovery in people after SCI when applied in combination with motor training protocols. There is limited research on the effects of combined stimulation with ts-ES and PNS/FES methods during walking.

Design/Methods:

In this clinical trial, participants received 4 weeks (45-minute sessions, 3 times per week) of locomotor treadmill training with personalized step-cycle based peripheral nerve and/or muscle stimulation with and without non-invasive lumbar ts-ES. PNS and FES methods were aligned with each individual's unique motor deficits. Before and after 4 weeks of training, clinical outcome measures of motor function (2 minute walk test, Berg Balance and modified SCIM-Mobility) along with metabolic analysis of heart rate (HR) and rate of oxygen consumption (VO2 sub-max) were performed. Non-invasive electromyography (EMG) and kinematic data were collected to assess motor function with and without ts-ES at each training session.

Results:

Based on feedback from participants, ts-ES stimulation with PNS/FES during training was tolerable, improved leg movement and facilitated muscle activity in knee extensors with 10-25% increased RMS amplitude of pre-training EMG activity during both forward and backward walking. Moreover, ts-ES tended to increase HR and VO2 sub-max within one session.

Conclusions:

Combining ts-ES with classical physiotherapy exercises and locomotor training has potential to increase motor and autonomic functional recovery. Development of personalized rehabilitation strategies for recovery following SCI will be aided by these findings.