A spinal cord injury (SCI) occurs when damage to the spinal cord disrupts the signals between the brain and the body, which can cause difficulty with movement. In a motor incomplete spinal cord injury (iSCI), the damage is partial, meaning the individual retains some muscle control below the site of the injury. A common therapy for people with an iSCI is locomotor training, which involves repetitive walking practice to help reteach the nervous system how to walk.

One technology that may be used to aid this process is Functional Electrical Stimulation (FES). FES uses small, safe electrical pulses to activate specific muscles, helping them contract. When combined with walking therapy, this is called FES-assisted locomotor training (FALT). The goal of FALT is to improve walking ability.

This research aimed to determine the long-term, therapeutic effectiveness of FALT. Specifically, scientists investigated whether this therapy improves walking speed and endurance in people with iSCI, focusing on gains that persist even when the FES device is turned off. To do this, they performed a systematic review, a process where researchers gather and analyze all existing studies on a topic.

The researchers searched for studies that tested FALT in people with iSCI and measured its lasting effects on walking. They collected the data from these studies and assessed their quality and risk of being biased or inaccurate using standard scientific tools (the Cochrane RoB2 and ROBINS-I tools). They then conducted a meta-analysis, which is a statistical method for combining the numerical results from multiple studies to get a more powerful overall result.

The search identified thirteen relevant studies. Four of these were randomized controlled trials (RCTs), a type of study where participants are randomly assigned to a treatment or a comparison group. Of these four, one was judged to have a low risk of bias, one had an intermediate risk, and two had a high risk of bias. The other nine studies were simpler pre-post tests, and all were found to have a high risk of bias, making their results less reliable.

The meta-analysis combined the data from three of the randomized controlled trials, which included a total of 76 participants. The analysis focused on FALT that was performed on a treadmill and compared it to control conditions, such as other types of walking therapy without FES. The results showed that FALT had a small effect on walking speed that was not statistically significant. This means the observed difference was so small that it could have been due to random chance rather than the therapy itself.

Similarly, when looking at walking endurance in 71 participants from these studies, the analysis found another small effect that was also not statistically significant. Again, this suggests that any improvement seen was not reliably different from what was achieved in the comparison groups.

Based on this analysis, the review did not find evidence that FES-assisted locomotor training improves walking speed or endurance for people with incomplete spinal cord injuries any more than other types of locomotor training. The researchers suggest that for FALT to be better evaluated in the future, studies should use more consistent methods and clearly report the amount of training and the specific electrical stimulation settings used. This would make it easier to compare results across different studies.