Demystifying Electrical Stimulation

Amy Bean
Friday, May 1st, 2020



In this months blog our aim is to give an overview of electrical stimulation in its simplest terms. Sometimes this commonly used intervention can seem a bit daunting to both therapists and users who at not familiar with it. The variety of terminology, wide range of devices and debate on when and how to use it all helps add to the confusion and needless complexity.

 

In the most simplest terms, electrical stimulation is the sending of an electrical impulse from a device, usually via surface electrodes stuck to the skin, to a nerve. These electrical impulses can be used to generate muscle contractions, modulate nerves to reduce pain or provide a low level sensory stimulation.

Sensory Electrical Stimulation (SES)

Sensory electrical stimulation is a low level stimulation that stimulates sensory neurons. As muscle neurons are not stimulated, no muscle contraction occurs. The stimulation is usually administered sub-sensory threshold i.e. the user doesn’t feel anything.

By providing low level SES, studies have shown that it improves excitability in the brain which can in turn lead to improved motor recovery after a neurological injury (Golaszewski et al 2012). Particularly for people who have little or no movement in their arm after a neurological injury it is a relatively easy way of providing much needed input to the arm.

 

Potential Benefits

 

How is it administered?

SES can be delivered via electro mesh garments or gel electrodes depending on which device you are using. These are applied to the body area that is being targeted.

In the UK it can be self administered. Although a therapist is not required, if you have any queries about suitability and application you may wish to seek advice from a therapist if you have access to one.

 

Who can use it?

Certain medical conditions are not safe to use it – see contraindications section at the end of this blog.

Anyone with impaired sensation, increased spasticity or reduced motor function after a neurological injury.

Anyone wishing to use our SaeboStim Pro with Sensory Accessory Kit can seek advice from our Clinical Specialist at Saebo UK.

 

NMES (Neuromuscular Electrical Stimulation)

NMES, sometimes called E-Stim or EMS (electrical muscle stimulation), is the delivery of electrical stimulation via surface electrodes to generate a muscle contraction. This is achieved by stimulating the peripheral nervous system (the system of nerves that branch out from the brain and spinal cord and extend to muscles and other organs). The electrical stimulation kickstarts the same sequence of events for a muscle to contract that has been impaired by the neurological injury.

 

Potential Benefits

  • Increased muscle strength
  • Increased range of movement of the muscle
  • Reduced spasticity (Stein et al 2015)

A combination of the above can lead to improved function (Yang et al 2019)

 

How is it administered?

There are a variety of devices available to purchase online ranging in price and complexity. All devices ultimately are designed to achieve the same goal of a muscle contraction, therefore simplicity and ease of use may be an important consideration when purchasing.

 

The electrical stimulation is delivered by surface electrodes that stick to the skin over the muscle. Guidance where to stick electrodes may either be in the device’s manual (as with our SaeboStim ONE ), via online resources or advice from a therapist.

 

It can be self administered, i.e. a therapist is not required.

There is some debate on how long it should be applied for but general consensus, based on research showing its effectiveness, is about 30 minutes per muscle group per day (Jae-Hyoung Lee et al 2017).

 

 

Who can use it?

Certain medical conditions are not safe to use it – see contraindications section at the end of this blog.

Anyone with reduced strength, increased spasticity, reduced range of movement, or reduced motor function after a neurological injury.

 

FES (Functional Electrical Stimulation)

This is simply where NMES, which is described above, is used in a functional context. Examples would be reaching to grasp an object, sit to stand or walking. Watch our Clinical Specialist demonstrating this here

The method in which this is achieved can either by working with the timing of the device, using a trigger button on the device to control exactly when the stimulation comes on (e.g. SaeboStim Pro), or a movement sensor which is typically used with FES devices for foot drop to help with the timing during walking.

Contraindications – medical conditions limiting safe use

Always check the device’s manual first.

Contraindications do change with new research and a good resource to keep up to date is http://www.electrotherapy.org/faqs

Generally agreed contraindications are :

  • Pacemaker (you may be able to use if you have one and have sought approval from your GP or Consultant)
  • Epilepsy, if uncontrolled.
  • Pregnancy

If you are in any doubt about safe use then always seek professional advice.




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