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  • Writer's pictureGenevieve Kirk

What are the Electrotherapies used by Veterinary Physiotherapists for?

Electrotherapies include the machines available to Physiotherapists to target healing in more focussed ways than what our hands alone are capable of. There are several different functions of these machines. These will hopefully be a bit clearer without being too heavy. If you are looking to be weighed down by the science, the next blog is the one! Please let us know if there’s something of real interest for you, so we can include it!


LASER works by using light energy to increase the activity in the engine of the cell: the mitochondria. These are part of cells, and are responsible for respiration, which produces the energy used all over ours and our horses’ bodies. When an injury is present, chemicals create bonds within mitochondria, and build up, stopping these mitochondria from doing their job efficiently. LASER helps to break down these bonds and the toxic build-up, which provides beneficial results such as:

- Pain relief

- Reduction of swelling

- Blood vessel growth

- Improved chemical composition of that area.

LASER is a popular choice of treatment for trigger points (muscle knots), joint pain, swelling and areas of tension that are too painful to attempt other modalities. This provides a non-invasive and well-accepted method of addressing pain in your horse, making it a vital tool. When your back is stiff, the last thing you want is for it to be hammered, consider your horse in the same way… before they teach you to consider it more severely! This also means the vets may not need to prescribe as much pain relief, meaning that your horses’ livers and kidneys will also be VERY grateful!

LASER light waves are unlike a standard LED; they produce the same wavelength, do not get spread from the light chamber, and create a uniform wave pattern. This characteristic makes these machines specific, effective… and expensive! Smaller “LASERs” are available on the market for less than £200, where the “proper” conventional class 3B ones are upwards of £1500. That price difference is not purely based on the bag it comes in! If someone is treating your horse with LASER and charging as such, it may be worth having a check on what the details of the machine are.

Therapeutic Ultrasound

Ultrasound uses soundwaves of energy which create changes in the body’s tissues. Not dissimilar to the concept of LASER in terms of energy delivery to increase the healing power of the treated location, but a different form of energy is delivered. UNLIKE LASER, this machine uses soundwaves, a mechanical form of energy, not light waves. With the different form of energy, come different benefits, different mechanisms of function, as well as different treatment targets. Shockwave therapy works on the same principle as Ultrasound; by also using mechanical waves to effect changes in the tissues.

I have a feeling my graphics skills need work...

Soundwaves create moments of compression and decompression in the tissues – imagine an accordion stretching in and out. This constant change in pressure seems to create gas bubbles in the treated tissue (cavitation), which then affect nearby cells to vibrate more (acoustic streaming). In tandem, the Ultrasound creates thermal (heating) effects, and non-thermal benefits.

It is possible to “overdo” this treatment. So it is CRUCIAL that the settings applied to the injury are appropriate to the healing stage (acute/subacute/chronic… go read that first blog post ;)). The suggested amount of energy delivered per pulse is different for each of these stages, where the setting for a chronic injury could destroy the tissues in acute stages of damage.

PEME/PEMF or Pulsed Electromagnetic Field Therapy

There is evidence of this modality treating bone fractures, osteoporosis and pain relief, however as with a lot of the research into most of these machines, different settings and machine specifications make it extremely difficult to compare any 2 studies. The basis of function for this machine is the therapeutic benefits that magnets have been associated with. Increased blood flow, pain relief, treatment of swelling and bone problems have all been associated, to varying degrees, with this modality.

This machine is particularly popular in the small animal world, as it seems to help the stiffness and pain of small animals getting up in the morning. Some large horse rugs use this technology, however there is not much scientific evidence for how effective these rugs actually are, especially when considered for the hefty price tags attached. Often an anecdotal summary of the product is found as opposed to research studies. Have you used any rugs that claim PEME benefits? (ActivoMed is a big one) What differences, if any, did you notice? I would love to know!


This is a muscle stimulation machine which is incredibly useful and effective at retraining coordination and maintaining muscle function. Pain has potent abilities to alter the contraction ability of muscles. Compensations, new or old, can start to affect a lifetime of muscle function. Imagine the days you’ve twisted your ankle and you limp for a week. Your other leg hurts and your back hurts from compensating. Imagine the pain and the dysfunction you feel when that twisted ankle hurts continually for weeks on end.

Horses may go a long time before we really notice that something is not quite right for them. That means, they may have spent a long time compensating, twisting their pelvis out and clenching their back, to avoid putting full weight on the sore leg. As a result, muscles will have seized up, locked up the painful area and brace the body against using it. The muscle contraction messages could then change, and the muscle function could change as a result. Allowing altered muscle contractions to continue runs the risk of secondary problems, as the body tries to respond to altered posture and muscle because the body starts to alter and respond to the different pressures.

H-wave can effectively re-stimulate the correct muscle sequence (with correct handling of it), WITHOUT fatiguing the muscle. The H-wave mimics the natural waveform that the body uses to contract a muscle; meaning it is generally well tolerated as well as effective. The other huge benefit to this machine is that it is capable of contracting the whole muscleas the electrodes are positioned on the muscle motor point, which is where all the nerve fibres enter a muscle and therefore where any contraction starts.

The H-wave can also be used to target pain relief, but the wave frequency used for this setting is generally poorly tolerated by horses. The “Muscle pump” function with the lower frequency is well tolerated, and also has a pain-relieving effect (thanks to improving the muscle quality).

NMES – Neuromuscular Electrical Stimulation

Similar to H-wave, this is a muscle stimulator. Unlike the NMES, this has a slightly sharper wavelength to create contraction, and it DOES cause fatigue in horses. This machine does however maintain and cause increased muscle strength, stamina and treatment of muscular atrophy.

With both of the muscle stimulation machines (H wave and NMES), neurologically deficit horses could benefit. These machines are able to artificially contract muscles, maintaining their function, reducing the risk of secondary problems such as contracture. Maintaining muscle function also means that fluid movement, lymph drainage, and delivery of fresh nutrients to the tissues of the muscles and surrounds is artificially maintained. This is hugely beneficial as the toxin build up and lack of drainage can cause pain, stiffness and discomfort secondary to the actual injury that is requiring treatment. Furthermore, a horse unable to work or preparing to recommence work after injury may be able to use muscles correctly from the beginning, if the treatment plan has been committed to.

TENS – Trans Cutaneous Electrical stimulation

This machine works by interfering with the pain-gate pathways in the body. In theory it is effective at treating pain in the body, though studies show varying lengths of time that relief is actually present for. This machine is often poorly tolerated by horses.

As ever, let us know what you’re thinking!

- Have your horses ever used any of these machines?

- Does your horse’s Veterinary Physiotherapist use them?

- Does your Vet believe in them?

Some are more popular than others, and it’s always interesting to hear a fresh take/opinion on the effectiveness and experiences people have with them! The next few posts will cover some of these in a deeper scientific way, destined for those with a keen desire to know more about the biological responses that each machine initiates.

See you in a week!

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