Electrophysical therapies

I use the following electrophysical therapies to provide pain relief and to speed up the healing of damaged tissue. Please click on the name of each therapy listed below for more information:

Pulsed electromagnetic therapy (PEME)

Low level LASER therapy/ phototherapy

TENS (transcutaneous electrical nerve stimulation)

NMES (Neuromuscular electrical stimulation)

Heat therapy

Cryotherapy

Pulsed electromagnetic therapy (PEME)

Quick summary of PEME

  • Used in dogs and cats
  • Main uses are to reduce pain and to improve tissue healing
  • Safe and comfortable during application
  • Beneficial in many patients as part of an integrated treatment programme e.g. for osteoarthritis, muscle spasm, post-operative recovery, management of elderly cats and dogs with reduced mobility.

 

PEME: Further information

With careful application, PEME is a particularly safe treatment modality. It causes animals no discomfort– indeed I get the impression that some individuals (particularly cats) can feel the PEME field and choose to lie against the pad when the machine is switched on.

An electrical current runs through wires in the PEME pad, and this induces a pulsed, oscillating electromagnetic field around the pad. When applied to the patient, this field causes a flow of charged particles within cells and tissues of the body.

PEME terminology:

PEME is sometimes called Pulsed Electromagnetic Field Therapy (PEMF therapy) and is similar to Pulsed Shortwave Therapy (PST). Unlike “shortwave diathermy” techniques, PEME has very little heating effect and uses a pulsed rather than a continuous magnetic field.

Uses of PEME:

I apply specific frequency and pulse rate settings to achieve different treatment effects:

  • Pain relief for osteoarthritis and other conditions (Trock et al 1994; Weintraub & Cole 2008) This can be used in combination with pain-relief medication if necessary.
  • Reduce tissue swelling and associated pain, e.g. after surgical procedures (Cheing et al. 2005)
  • Improve blood flow to muscle, e.g. for conditioning key muscles in athletic animals
  • Aid healing of injured muscle
  • Aid early healing of damaged ligament (Lin et al. 1992)
  • Aid fracture repair (Sharrard 1990)

PEME is usually applied for 10-15 minutes. Wherever possible, I take this opportunity to continue with other treatments such as myofascial release or massage.

How does PEME achieve its biological effects?

Theories include the following:

  • Changes in ion distribution across cell membranes may alter chemical processes, especially those involved in inflammation (Goats 1989)
  • Changes in nerve impulse transmission including a reduction in impulses to and within slow C nerve fibres. This reduces the perception of pain. (Laycock 2009)
  • Chemical reactions in cells initiated by the activation of cell membrane ATPase by the PEME field (Tsong 1989). This may lead on to improved cell nutrition, repair, etc.
  • Bone effect: a damped oscillation in synchrony with one of the mechanical resonant frequencies of the bone is created. This may facilitate bone healing, partly by attracting osteoblasts (cells that produce new bone) to the area. (Laycock 2009)

PEME: some references

Cheing, G., Wan, J., & Kai Lo, S. (2005). Ice and pulsed electromagnetic field to reduce pain and swelling after distal radius fractures. Journal of rehabilitation medicine, 37(6), 372-377.

Goats, G. C. (1989). Pulsed electromagnetic (short-wave) energy therapy. British journal of sports medicine, 23(4), 213-216.

Laycock, D. C., & Laycock, M. M. (2009). Frequency specific Treatments for Neuromuscular and Orthopaedic injuries.

Lin, Y., Nishimura, R., Nozaki, K., Sasaki, N., Kadosawa, T., Goto, N., & Takeuchi, A. (1992). Effects of pulsing electromagnetic fields on the ligament healing in rabbits. The Journal of veterinary medical science/the Japanese Society of Veterinary Science, 54(5), 1017-1022.

Sharrard, W. J. (1990). A double-blind trial of pulsed electromagnetic fields for delayed union of tibial fractures. Journal of Bone & Joint Surgery, British Volume, 72(3), 347-355.

Trock, D. H., Bollet, A. J., & Markoll, R. I. C. H. A. R. D. (1994). The effect of pulsed electromagnetic fields in the treatment of osteoarthritis of the knee and cervical spine. Report of randomized, double blind, placebo controlled trials. J Rheumatol, 21(10), 1903-11.

Tsong, T. Y. (1989). Deciphering the language of cells. Trends in Biochemical Sciences, 14(3), 89-92.

Weintraub, M. I., & Cole, S. P. (2008). A randomized controlled trial of the effects of a combination of static and dynamic magnetic fields on carpal tunnel syndrome. Pain Medicine, 9(5), 493-504.

 

Low level LASER therapy/ phototherapy

Quick summary of LASER/phototherapy:

  • Useful for treating structures close to the skin surface (e.g. skin wounds, “lick granulomas”, some superficial tendons and ligaments)
  • Safe and completely comfortable if applied correctly
  • Towel and safety goggles are used to shield the strong beam from view.

LASER/ phototherapy: Further information

Veterinary applications for phototherapy include improvements in tissue healing and pain control. Completely comfortable for the animal during application and with an excellent safety profile, my phototherapy machine is a superluminescent diode device also used at top veterinary institutions including the Dick White Referral Centre.

When using phototherapy, I use a towel to shield the patient’s and owner’s eyes from the powerful beam, while protective glasses enable me to keep a check on treatment progress. Low level LASER/phototherapy does not reach the deeper tissues of the body, so I mainly reserve this treatment for wound healing or for structures that lie close to the skin surface.

Documented therapeutic effects of low level LASER/phototherapy include:

  • Enhanced wound healing (Enwemeka et al 2004; Bossini & Fangel 2009). This involves many factors including the increased lay-down of collagen and the increased growth of new blood vessels.
  • Pain control, e.g. in osteoarthritis (Bjordal et al 2007)
  • Enhanced healed of damaged nerves (Rochkind et al 1990)
  • Enhanced healing of tendon (Elwakil 2007) and ligament
  • Possible improved muscle function and recovery (Leal-Junior et al 2013)

Some references for low level LASER/phototherapy:

Bjordal, J. M., Johnson, M. I., Lopes-Martins, R. A., Bogen, B., Chow, R., & Ljunggren, A. E. (2007). Short-term efficacy of physical interventions in osteoarthritic knee pain. A systematic review and meta-analysis of randomised placebo-controlled trials

Bossini, P. S., R. Fangel, et al. (2009). “Low-level laser therapy (670 nm) on viability of random skin flap in rats.” Lasers Med Sci 24(2): 209-213.

Chow, R.T. et al (2009). Efficacy of low-level laser therapy in the management of neck pain: a systematic review and met-analysis of randomised placebo-controlled trials. Lancet vol 374 p 1897-1908

Elwakil, T. F. (2007). An in-vivo experimental evaluation of He–Ne laser photostimulation in healing Achilles tendons. Lasers in medical science, 22(1), 53-59.

Enwemeka, C. S., Parker, J. C., Dowdy, D. S., Harkness, E. E., Harkness, L. E., & Woodruff, L. D. (2004). The efficacy of low-power lasers in tissue repair and pain control: a meta-analysis study. Photomedicine and Laser Therapy, 22(4), 323-329

Leal-Junior, E. C. P., Vanin, A. A., Miranda, E. F., de Carvalho, P. D. T. C., Dal Corso, S., & Bjordal, J. M. (2013). Effect of phototherapy (low-level laser therapy and light-emitting diode therapy) on exercise performance and markers of exercise recovery: a systematic review with meta-analysis. Lasers in medical science, 1-15.

Rochkind S, Barr-Nea L, Volger I. Spinal cord response to laser treatment of injured peripheral nerve. Spine 1990;15:6–10.

 

 TENS (transcutaneous electrical nerve stimulation)

Quick summary of TENS:

  • Used in dogs and cats
  • Useful for pain relief for acute and chronic conditions.
  • Some fur needs to be clipped to allow good skin contact with the electrode pads.
  • Can feel “tingly” or “odd” before its effect kicks in, so needs to be applied by a competent practitioner who can assess how the animal is feeling and adjust settings as needed.

TENS: Further information

TENS is familiar to many in the UK as a gentle mode of pain-relief during labour or for chronic back pain, etc.

The requirement to clip fur limits the use of TENS in small animal practice. However, I do use this modality regularly during the first days following orthopaedic surgery. In this instance, it adds to the pain-relief programme and there is generally sufficient fur already clipped to enable treatment. Where animals are reluctant to use the limb after surgery, application of TENS along with other modalities (e.g. ice, PEME, touch therapies) often enables some subsequent gentle weight-bearing.

TENS: Further reading

JOHNSON M, Martinson M. Efficacy of electrical nerve stimulation for chronic musculoskeletal pain: a meta-analysis of randomized controlled trials. Pain. 2007;130:157–165

NMES (Neuromuscular electrical stimulation)

Quick summary of NMES:

  • I mainly reserve this therapy for partially-paralysed (hemiplegic or tetraplegic) animals.
  • NMES is used to activate and strengthen specific muscles.
  • 2-4 electrode pads are applied to the skin after clipping away any fur.
  • NMES causes muscles under the electrode pads to contract.
  • The sensation can vary from “odd” to “uncomfortable”, so NMES should be applied by a competent practitioner who can assess how the animal is feeling and adjust settings as needed.

NMES post-op

NMES: Further information

This therapy is particularly useful on the small animal neurology ward. During early recovery from spinal disc disease or from conditions such as fibrocartilaginous embolism, some animals are barely able to move their limbs. I do my best to encourage early muscle use by providing a combination of exercises and supported movements. However, those animals with no, or almost no, voluntary movement in major muscle groups are at risk of muscle wasting which would hinder further rehabilitation. In these cases, NMES is a useful way to stimulate those key muscles.

Several factors limit the use of NMES in small animal patients.  This modality can be uncomfortable at higher settings and, while some discomfort may be tolerated in human patients who understand the benefits of treatment, animals should of course be kept within their “comfort zone” throughout treatment for welfare reasons.  The pattern of muscle stimulation produced by NMES is different to that produced during a volitional muscle contraction and it can cause quite rapid patient fatigue. Furthermore, unlike rehabilitation exercises, NMES does not help the patient to relearn essential patterns of movement. Whenever including NMES in my rehabilitation programme, I therefore make a point of starting movement/exercise therapies as soon as possible.

NMES: Further reading

Doucet, B. M., Lam, A., & Griffin, L. (2012). Neuromuscular electrical stimulation for skeletal muscle function. The Yale journal of biology and medicine, 85(2), 201.

Sheffler, L. R., & Chae, J. (2007). Neuromuscular electrical stimulation in neurorehabilitation. Muscle & nerve, 35(5), 562-590.

 

Heat therapy

Quick summary of heat therapy:

  • Used in dogs and cats
  • Beneficial in many cases of chronic (long-term) pain or injury including osteoarthritis and tendinopathy. 
  • Can be helpful in relaxing tight, painful muscles.
  • It is useful to apply heat prior to attempting either “range of movement” or stretch-type exercises.
  • Should generally be avoided during the first few days of severe inflammation.
  • Heat therapy can be continued by the owner at home in some cases.

Heat therapy: further information

Warmth can be applied using a microwaveable hot gel pack, pocket-size “hand-warmers” as available from camping shops, or as warm water from a shower attachment. Safety is of greatest importance…the temperature of any thermal device must be carefully controlled, and hot packs should be covered appropriately.

I always keep a check on my patient’s body language when applying this mode of therapy- some individuals seem to gain great relief from having a heat pack applied while others can find it overwhelming, particularly on a warm day.

Heat therapy: how does it work?

  • Heat causes local vasodilatation (widening of blood vessels) and therefore improves the blood supply to the area. As a consequence of this, tissue oxygenation is improved thus facilitating healing.
  • Heat reduces muscle spasm by reducing the firing rate of muscle spindle fibres while increasing the firing rate of Golgi tendon organs (Heinrichs 2004).
  • Heating collagenous tissue increases its flexibility (Lehmann et al 1974).
  • If tissue is heated before being stretched, less force is needed to obtain an increase in tissue length, the risk of tissue damage is reduced and the increased tissue length is retained for an increased time.
  • By reducing muscle spasm, heat relieves compression of blood vessels and thus further improves blood flow.

Heat therapy: some references

Heinrichs, K. (2004). Superficial thermal modalities. Millis DL, Levine D, Taylor RA, eds. Canine rehabilitation and physical therapy. Philadelphia: Saunders, 277-288.
Lehmann, J. F., Warren, C. G., & Scham, S. M. (1974). Therapeutic heat and cold. Clinical orthopaedics and related research, 99, 207-245.

Cryotherapy (cold therapy)

Quick summary of cryotherapy:

  • Used in dogs and cats.
  • Often beneficial during early recovery from injury or orthopaedic surgery 
  • Reduces pain and inflammation.
  • This therapy can be continued at home by the owner in some cases.

 

Cryotherapy: Further information

Having had an operation on both stifle joints the previous day, a gauze-wrapped ice-pack is used in combination with pulsed electromagnetic therapy and touch techniques. Immediately after this session, this little dog felt comfortable enough to do a little slow-walking.

Having had an operation on both stifle joints the previous day, a gauze-wrapped ice-pack is used in combination with pulsed electromagnetic therapy and touch techniques. Immediately after this session, this little dog felt comfortable enough to do a little slow-walking.

Cryotherapy involves the therapeutic cooling of a body part, and is usually performed to reduce pain and to minimise swelling (oedema). For small animals, this generally involves application of a covered frozen gel pack to the affected area for up to about ten minutes at a time. I often use frozen gel packs in combination with pulsed electromagnetic therapy as this may lead to improved analgesic (pain-relief) effect (Cheing et al 2005).

In applying frozen gel packs, we must remember that animals with tiny body size, the very young, the very old and those during early recovery from general anaesthetic will be easily over-chilled, so care must be taken to maintain their core body temperature. It is also important to cover the ice pack, e.g. with moistened gauze swabs, in order to prevent “freezer burn” to the skin.

Cryotherapy: How does it work?

Inflamed body tissues are hot, red, swollen and painful. At the cellular level, inflammation involves a cascade of events including changes to blood vessel walls, haemorrhage, movement of fluid out of cells, reduced tissue oxygen levels and release of inflammatory mediators including bradykinin from damaged cells. These mediator chemicals affect sensory nerves, making them more reactive to further stimuli (peripheral sensitisation) and this results in further pain and tenderness (Kidd & Urban 2001)

Cooling the body tissues reduces the effects of inflammation in the following ways (Sunitha 2010):

  • In reducing the local metabolic rate, it enables cells to cope better with low tissue oxygen levels, and reduces the rate at which bradykinin, etc., are released.
  • By reducing release of inflammatory mediators, cooling reduces vessel permeability and the development of oedema (tissue swelling).
  • Cryotherapy reduces pain at least in part through its effect of reducing nerve conduction velocity.
  • By reducing the release of inflammatory mediator chemicals, peripheral sensitisation (which would lead to further pain and tenderness) is reduced.

Cryotherapy: some references

Cheing, G., Wan, J., & Kai Lo, S. (2005). Ice and pulsed electromagnetic field to reduce pain and swelling after distal radius fractures. Journal of rehabilitation medicine, 37(6), 372-377.

Kidd, B. L., & Urban, L. A. (2001). Mechanisms of inflammatory pain. British Journal of Anaesthesia, 87(1), 3-11.
 
Sunitha, J. (2010). Cryotherapy–A Review. Journal of Clinical and Diagnostic Research, 4, 2325-2329.
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