Electrical Stimulation

Electrical stimulation is a treatment modality that has been used in many different populations with the goal of strengthening weak muscles. ES involves the application of electrical current, usually using a small device with electrodes placed on the skin over peripheral motor nerves or their associated muscles. The device administers low level electric current which then causes activation or contraction of the muscle.

When ES is applied during the completion of a functional task, it is referred to as functional electrical stimulation (FES). The electric impulse in this situation leads to a desired function i.e. contracting muscles to move an arm or a foot. For example, in children with cerebral palsy, FES has been used to facilitate walking, correct gait abnormalities, and prevent foot drop. And with the development and commercial availability of lightweight wearable NMES devices, it is receiving more attention as a treatment option.

ES has been used for a variety of conditions with many therapeutic goals. It can be used to increase muscle activation and strength, decrease joint pain and swelling, and improve blood flow and circulation, among others. In children with CP, the treatment has been studied as a modality to increase muscle strength and range of motion, improve spasticity, foot/ankle positioning, gait and walking speed as well as in the treatment of swallowing disorders (dysphagia).

There are several terms used to describe this intervention. Electrical stimulation is also known as neuromuscular electrical stimulation (NMES) and sometimes also referred to as electrical muscle stimulation (EMS). It can be used as a muscle strengthening intervention during physiotherapy. Functional electrical stimulation (FES), on the other hand, is the application of NMES to promote and achieve functional movements. Regardless of the term used, the general goal of improving motor control and, ultimately, function is the same.

There is limited evidence regarding the effectiveness of ES as an early intervention for children with CP. Even though ES has been used in children with CP for decades, most of the research is on its use in older children. Only 3 recent studies including children under 5 years old with CP were found and reviewed for this module.

The first high quality study examined the effect of functional electrical stimulation used in combination with physiotherapy in children with spastic CP. The results showed that the children in the study (age 2-10 years) who received FES 5 days/week for 4 weeks in addition to physiotherapy improved more in their sitting balance and trunk asymmetry than those who received only physiotherapy.

The second high quality study showed that ES combined with traditional dysphagia rehab resulted in improved swallowing function and dysphagia level compared to sham stimulation with traditional dysphagia rehab. Specifically, the study found that children (between the ages of 2-6 years) receiving ES had less drooling, increased chewing and tongue movements, improved ability to eat large food, and shorter feeding times, after 4 weeks of treatment.

The third high quality study compared three different interventions: ES used together with constraint-induced movement therapy (CIMT), CIMT used alone, or occupational therapy. The study found that there was no difference between the three approaches in improving upper limb movement or grip strength in children (ages 2-14 years) with hemiplegic CP. However, ES with CIMT was found more effective than both occupational therapy and CIMT used alone in improving muscle recruitment and coordination, even 6 months after the treatment.

Prior to the start of intervention, you can expect an initial assessment with a physiotherapist. In the course of the assessment, the amount of electric current to be used for treatment will be determined. This is done by placing the electrodes on the skin over the targeted muscle and slowly increasing the intensity of the current until it causes the muscle to contract. This level of stimulation (minimum amount required for muscle contraction) could later be increased during treatment as the child becomes more used to it.

ES is usually provided by physiotherapists or occupational therapists in clinic.

In some cases, NMES devices can also be used at home, especially with older children.

There is no set protocol for the frequency or duration of this intervention. In the studies reviewed for this module, ES was applied in 20-30-minute long sessions, 5 days/week, for 2-4 weeks.

The duration of the treatment will be determined based on the specific therapy goals and needs of the child.

No specific side effects or risks were reported in the reviewed studies.

The procedure is generally considered safe despite the lack of information regarding long term effects of use. The electrical current used for this type of treatment is low and unlikely to cause pain. A slight tingling (“pins and needles”) sensation is common which most people find tolerable. In some cases, the device may also cause skin irritation.

If you have any concerns, we suggest you discuss these with the treatment provider.

ES is most commonly used in children with CP to address movement issues, muscle spasticity, and swallowing disorders. Though the evidence is still limited, this type of intervention is showing promising results in treating these issues. In the reviewed studies, electrical stimulation was used for children as young as 2 years old and with all GMFCS levels. It is worth noting that all three studies reviewed used ES in combination with other standard treatments. So although the research is promising, there is not much known about the effectiveness of ES as a stand alone treatment in young children with CP.

Information on this website is provided for informational purposes only and is not a substitute for professional medical advice.

One high quality RCT (Karabay et al., 2012) investigated the effects of functional electrical stimulation (FES) on sitting balance in children with spastic diplegic CP. This high quality RCT randomized patients to receive FES or no treatment; both groups received physical therapy rehabilitation (neurodevelopmental approach). Sitting balance was assessed using the Gross Motor Functional Measure – Sitting score at post-treatment (4 weeks). A significant between-group difference was found, favoring FES vs. no treatment.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that functional electrical stimulation is more effective than no treatment in improving sitting balance for children with spastic diplegic CP.

One high quality RCT (Karabay et al., 2012) investigated the effects of functional electrical stimulation (FES) on trunk asymmetry (seated) in children with spastic diplegic CP. This high quality RCT randomized patients to receive FES or no treatment; both groups received physical therapy rehabilitation (neurodevelopmental approach). Trunk asymmetry was assessed using radiographic measurements of Kyphotic Angle, Cobb Angle and Sacral Angle at post-treatment (4 weeks). Significant between-group differences were reported for Kyphotic Angle and Cobb Angle, favoring FES vs. no treatment.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that functional electrical stimulation is more effective than no treatment in improving trunk asymmetry for children with spastic diplegic CP.

One high quality RCT (Umay et al., 2020) investigated the effects of sensory level electrical stimulation (ES) combined with a conventional dysphagia rehabilitation on dysphagia in children with CP (including a mixed population of types and severity of CP). This high quality RCT randomized patients to receive sensory level ES or sham stimulation; both groups received conventional dysphagia rehabilitation. Dysphagia was evaluated by the Pediatric Eating Assessment Tool-10 and the Flexible Fiberoptic Endoscopic Evaluation of Swallowing at post-treatment (4 weeks). Significant between-group differences were found on both measures, favoring ES vs. sham stimulation.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that sensory level electrical stimulation is more effective than a comparison intervention (sham stimulation) in improving dysphagia for children with CP presenting with oropharyngeal dysphagia symptoms.

One high quality RCT (Xu et al., 2015) investigated the effects of electrical stimulation (ES) and constraint-induced movement therapy (CIMT) on grip strength among children with hemiplegic cerebral palsy. In this high quality RCT, children were randomized to receive CIMT only, CIMT and electrical stimulation (ES), or traditional occupational therapy only. Grip strength was assessed using a Sphygmomanometer at post-treatment (2 weeks from baseline) and follow-up (3 months and 6 months from baseline).  No significant between-group differences were found at any time point.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that electrical stimulation with CIMT is not more effective than the comparison interventions (CIMT only; traditional occupational therapy) in improving grip strength in children with hemiplegic CP.

One high quality RCT (Xu et al., 2015) investigated the effects of electrical stimulation (ES) and constraint-induced movement therapy (CIMT) on muscle recruitment and coordination among children with hemiplegic cerebral palsy. In this high quality RCT, children were randomized to receive CIMT only, CIMT and electrical stimulation (ES), or traditional occupational therapy only. Muscle recruitment and coordination (root mean square (RMS) of involved/uninvolved wrist extensors/flexors; integrated EMG (iEMG) of involved/uninvolved wrist extensors/flexors; cocontraction ratio) were assessed using surface EMG at post-treatment (2 weeks from baseline) and follow-up (3 months and 6 months from baseline). Significant between-group differences were found only for 2 measures (iEMG of the involved wrist extensors and cocontraction ratio) at follow-up (both 3 and 6 months from baseline), favoring CIMT + ES vs. CIMT only.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that electrical stimulation with CIMT is more effective than the comparison interventions (CIMT only; traditional occupational therapy) in improving muscle recruitment and coordination in children with hemiplegic CP.

One high quality RCT (Xu et al., 2015) investigated the effects of electrical stimulation (ES) and constraint-induced movement therapy (CIMT) on upper limb motor function among children with hemiplegic cerebral palsy. In this high quality RCT, children were randomized to receive CIMT only, CIMT and electrical stimulation (ES), or traditional occupational therapy only. Upper limb motor function was assessed using the Upper Extremity Functional Test and Global Rating Scale at post-treatment (2 weeks from baseline) and follow-up (3 months and 6 months from baseline). No significant between-group differences were found at any time point.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that electrical stimulation with CIMT is not more effective than the comparison interventions (CIMT only; traditional occupational therapy) in improving upper limb motor function in children with hemiplegic CP.