FES-assisted Gait Training for Incomplete Spinal Cord Injury

Automated Multi-channel Closed-loop Functional Electrical Stimulation Assisted Gait to Improve Gait in People With Incomplete Spinal Cord Injury

Spinal cord injuries (SCI) impair neural communication, leading to difficulties in walking due to muscle weakness, altered reflexes, and impaired muscle activation below the injury. Functional electrical stimulation (FES) has been shown to enhance voluntary control, strength, and walking performance when used during gait training. This study aims to assess whether the FES yields superior improvements in walking ability compared to conventional gait training without stimulation.

Background:

Spinal cord injury (SCI) disrupts neural communication, resulting in impaired walking ability due to muscle weakness, altered reflex modulation, and reduced voluntary muscle activation below the lesion level. Functional electrical stimulation (FES) applied during gait training has been shown to enhance muscle activation and improve gait performance. However, it remains unclear whether gait training with automated multi-channel FES provides additional benefits beyond conventional treadmill gait training in individuals with chronic incomplete SCI (iSCI).

Objectives:

(1) To determine whether gait training combined with FES leads to greater improvements in overground walking speed compared to improvements observed during the preceding period of conventional gait training alone. (2) To evaluate retention of walking improvements following the FES intervention. (3) To explore whether changes in gait performance are associated with changes in muscle coordination and muscle strength.

Methods:

This study is a prospective single-group, repeated-measures study with two sequential intervention phases: 10 weeks of conventional treadmill gait training followed by 10 weeks of gait training with FES. Individuals with chronic iSCI (≥12 months post-injury; AIS C or D; neurological level C2-T12) will participate in a 23-week program. Assessments will be performed at baseline (T0), after conventional training (T1), after FES gait training (T2), and at 10-weeks post intervention (T3). The primary outcome is the 10-Meter Walk Test (10MWT) walking speed (m/s). The primary analysis compares the change in 10MWT performance during the FES-assisted phase (T2-T1) with the change during the conventional phase (T1-T0). Secondary outcomes include spatiotemporal gait parameters, Walking Index for Spinal Cord Injury II, Hoffer classification, treadmill gait performance, muscle activity, and isometric leg muscle strength.

Inclusion Criteria:

• Have a non-progressive chronic (>1 yrs) incomplete SCI between C4 and T12 with an ASIA score of C or D.
• Be at least 18 years of age.
• Be able to take some steps (with assistive devices or in the bridge).
• As part of the inclusion process, responsiveness to electrical stimulation will be assessed using a Compex electrical stimulator (Compex SP 4.0; Compex Medical SA, Switzerland) to ensure potential participant's respond well to ES, and to ensure that the sensitivity threshold is not reached before motor response in all target muscles.

Exclusion Criteria:

• Flaccid paralysis.
• Musculoskeletal dysfunction, uncured fractures, contractures, pressure injuries, or infections that could impede the intended training.
• Botox injections in the lower extremities during the last six months.
• Women who are (planning to get) pregnant during the study period.
• Implanted neurostimulator or stimulator of any kind that can have an influence on the safe use of ES.
• Pacemaker, or other device, present in the body that prevents the safe use of ES.
• Inability to communicate well or have cognitive disorders.
• Currently being enrolled in another training study or participated in a training study in the previous six months.
• Having an illness that has a high chance of preventing them to be able to perform the training at a sufficient frequency.