History of Electrical Stimulation for Wound Healing

About 300 years ago, electrically charged gold leaf was used to treat and enhance skin healing from smallpox lesions. Electrical stimulation therapy can be separated into 2 different types: High Voltage Pulsed Stimulation and Microcurrent Electrical Stimulation. In this blog, our main focus is on Microcurrent Electrical Stimulation. 

Terminology

There are different names for microcurrent electrical stimulation, for example: low level direct electrical current therapy, microcurrent electrical therapy (MET), micro-amp therapy, microamperage electrical stimulation and Low-intensity Electrical Stimulation.

The first electrical therapy machine (Dermatron), a device using electrical stimulation to promote bone fracture healing, was developed in 1960 by the German Doctor Reinhold Voll (Barret, S 2011). 

Figure 1: Dermatron

Previous studies suggested that microcurrent therapy could achieve the following: 

History of tissue healing 

• 1.       Increase cell division (Bayat et al. 2006)
• 2.       Stimulate secretion of growth factor  (Chapman-Jones & Hill, 2002) (Cheng et al. 1982)
• 3.       Stimulate ATP Synthesis (Lee et al. 2010) (Cheng et al. 1982)
• 4.       Accelerate wound healing (Lee et al.  2007, 2010)
• 5.       Improve fracture union (Kalamed Corporation)
• 6.       Increase wound epithelialisation (Santos et al. 2004)

Animal studies :

Frick & McCauley (2005) reported that a very large wound (18 inches) on a 2- year-old horse’s right rear quarter leg had shown substantial healing after 10 days of MET. Initially, the large wound only showed slow progression of healing in one month post-surgery, flushing and treating with antibiotics. This was due to the area failing to develop healthy granulation of tissues and becoming infected before applying MET. 

Figure 2 shows the original wound with infection and the electrode attachment site respectively. Figure 3 showed the healing and a clean wound without infection after 10 days of MET. Figure 4 was taken after 22 days MET treatment and finally after approximately 4 months when the horse had returned to training. 

Figure 2: Left: Initial state of wound before MET treatment , Right: Placement of electrode

Figure 3: State of wound after 10 days of MET treatment and showed clean wound

Figure 4: Left: State of wound after 3 weeks of MET treatment, Right: 4 months after returns to training

Another horse study from Marshall found that a normally 3 month long healing period for a suspensory ligament injury had been reduced greatly, with significant healing after 21 days of MET. Shortening the bone fracture healing period was also reported in another horse study by Kalamed, which introduced a bone growth stimulator based on magnetic stimulation. 

Bayat et al. (2006) explained that the MET application significantly accelerated the wound healing of full-thickness incision in rabbits’ skin by increasing the fibroblasts after 7 days. Moreover the strength increased after 15 days. Similar studies have found that MET reduced the length of restoration of the area undergone TCA peeling in rats’ skin and increased amount and structure of fibroblasts and collagen (Santos et al. 2004). 

Figure 5: Fibroblasts in ten zones of incisional wound bed in rabbits of sham-treated (Sham) (n = 15) and experimental (Ex) (n = 15) Ex groups showed significant difference  at day 7 (Bayat et al. 2006).

Figure 6. Ex group showed significant difference at day 15 in tensile strength (Bayat et al. 2006)

Human studies: 

MET has shown that chronic skin ulcers and abdominal wounds, present for an average of 16.5 months which did not respond to standard conservative treatment, experienced significantly accelerated healing (Lee et al., 2007). In a study on chronic achillies tendinopathy, it was shown that there was significant improvement in MET compared to the control group by observing four different indicators including clinical examination, ultrasound imaging, range of movement, and self - assessment (Chapman-Jones. & Hill 2002). 

Figure 7. Difference in pain and stiffness between groups A (conversative treatment:control) and B (microcurrent regime) using mean score over four assessment intervals (Chapman-Jones. & Hill 2002).

MET has been also been used patients with diabetes mellitus, hypertension and chronic wounds. Evidence shows that the wounds were significantly healed by 30-100%. Some patients were able to reduce their medication or completely stop after MET treatment (Lee, 2010).

It is obvious that MET could increase the healing process in animal and human studies. Let’s look at how it works next!

Reference

Barret, S. (2011), Quack "Electrodiagnostic" Devices http://www.quackwatch.org/01QuackeryRelatedTopics/electro.html

Bayat, M., Asgari-Moghadam, Z., Maroufi, M., Sadat-Rezaie,F.,Bayat, M. & Rakhshan, M. (2006), Experimental Wound Healing using Microamperage Electrical Stimulation in Rabbit, Journal of Rehabilitation Research & Development,(43)2, 219-226

Chapman-Jones, D. & Hill, D. (2002), Novel Microcurrent Treatment is More Effective than Conventional Therapy for Chronic Achilles Tendiopathy -Randomised comparative trial, Physiotherapy, (88)8, 471-480


Cheng, N., Van Hoff, H., & Bockx, E. (1982) The effect of electriccurrents on ATP generation protein synthesis, and membrane transport in rat skin, Clinical Orthopedics 264 -272

Frick, A. & McCauley, D. (2005), Microcurrent Electrical Therapy, Journal of Equine Veterinary Science 418 - 422

Kalamed Corporation, Electrical Bone Growth Stimulator, Journal of Equine Veterinary Science

Lee, B.Y., Al-Waili, Stubbs, D., Wendell, K., Butler, G., Al-Waili, T.,& Al-Waili, A. (2010), Ultra-low Microcurrent in the Management of Diabetes Mellitus, Hypertension and Chronic Wounds: Report of Twelve Cases and Discussion of Mechanism of Action, Inernational Journal of Medical Sciences, (7)1, 29-35

Lee, B.Y., Wendell, K., Al-Waili, N. & Butler, G., (2007), Ultra-Low Microcurrent Therapy: A Novel Approach for Treatment of Chronic Resistant Wounds, Advances in Therapy, (24)6, 1202-1209

Marshall, D.  Mircro-current TENS in Treating Ligament Injuries, Journal of Equine Veterinary Science

Primack, N. The History of Microcurrent Stimulation http://www.texas-medical.com/info/mchistory.htm

Santos, V.N.S., Ferreira, L.M., Horibe, E.K.,& Duarte, I.S.(2004) Electric microcurrent in the restoration of the skin undergone a trichloroacetic acid peeling in rats. Acta Cir Bras, (19),5, 466-470