Achilles tendon ruptures impact over 11,000 people annually in the UK (1), and approximately 52% of recreational runners have suffered from an incidence of Achilles tendinopathy in their lifetime (2). A number of NuroKor athletes and consumers have used our technology to assist with Achilles tendon injuries. This article will define Achilles tendinopathy, and explain common treatment methods used during rehabilitation or post-surgery. We will explain in-depth how the bioelectrical treatment modality, Microcurrent Stimulation, can benefit tendon healing and scar tissue repair in Achilles tendinopathy.

What is achilles tendinopathy?

Achilles tendinopathy is a common cause of impaired physical performance in athletes and the general population, it is characterised by the symptoms of tenderness, pain and swelling. It occurs when there is a tear of the band of tissue (tendon) that connects the calf muscle to the heel bone, and depending on the severity of the tear can be treated with non-surgical or surgical interventions. It is diagnosed by clinical symptoms and imaging methods like ultrasonography and/or magnetic resonance imaging.

 The first step treatment choices depend on the damage, and can differ on a case by case basis. Common treatment modalities include usage of; non-steroidal anti-inflammatory drugs, footwear and orthoses, shock therapies, eccentric stretching exercises during physiotherapy followed by platelet rich plasma, steroid and/or analgesic injections. In a case report electrical stimulation has been deemed an effective treatment therapy for increasing strength and decreasing the symptoms of pain.

Bioelectrical modalities utilised by NuroKor such as; Peripheral Nerve Stimulation (PNS) and Neuromuscular stimulation (NMS) offer a non-invasive, drug-free alternative to achieve pain relief (PNS) and can optimise recovery through improved circulation and muscle activation.

When surgical intervention is necessary

Tendon degeneration reduces the mechanical strength and predisposes it to rupture (3). The Achilles tendon is advised to be reattached, if detached by >50% (4). If the rupture is severe or the patient is active, doctors may advise surgical procedure. During the surgery, the skin and the underlying tissue (including small vessels and nerves) are incised gently with a sharp knife to reach the tendon. After surgery, the wound is expected to close on the surface level in a short period of time if there is no infection or trauma. However, the total healing process can take more than a year to complete and there will be scar tissue formation.

The scar tissue results from the biological processes of wound repair which contains fibrinoid tissue, it is less durable and elastic when compared to non-damaged tissues. The amount of the scar tissue size changes on an individual basis. The scars can be seen easily from the skin but the internal scar formation under the skin is microscopic and therefore cannot be seen with eyes. The total healing process involves a series of mechanisms where a massive amount of cells and biological cascades are involved (5). It is important to consider rehabilitation treatments post-surgery to assist with tendon healing and internal and external scar tissue healing. Microcurrent is one modality which can assist with this process. 

Figure 1 and 2 show the thermal imaging and photo of the right Achilles tendon of a diabetic patient who had tendon rupture and operation. From the thermal image, it can be clearly seen that the right Achilles region has a higher temperature. Complications affecting the lower limbs are the most common manifestations of diabetes

Microcurrent stimulation for tendon healing and scar tissue

Microcurrent is a bioelectronic technology which utilises the body’s natural bioelectrical current to help promote tissue repair and the recovery process, it can be used as a promising treatment for tendon healing (7-18). Electrical stimulation is a non-invasive, easy to use technique which can be utilised at home without the need for assistance. It is suitable for prolonged and repeated use for lower extremities. 

Microcurrent is an important modality to use post-surgery to decrease the scar tissue associated with Achilles tendinopathy. It has been shown that usage of microcurrent application has produced positive results in the 3rd, 5th, and 8th week post-surgery. These results include, reduced inflammation and the promotion of reorganisation of the collagen fibres in the Achilles injury (6).

Lower the incidence of re-rupture in Achilles Tendinopathy 

It has been measured that healed tendons have lower biomechanical resistance than the normal tendon and re-rupture is an unwanted risk after the tendon injuries. Microcurrent treatments may benefit to lower the incidence of re-rupture and improve tendon repair,

One of the randomised controlled prospective experimental studies showed that the usage of a specific microcurrent protocol on the Achilles tendon of rats increased the mechanical resistance and improved healing only four weeks after the injury was sustained (7).

How microcurrent can assist with post-injury microcirculation

Microcurrent devices are designed to mimic and amplify the bioelectrical signals of the body. Some studies demonstrate the beneficial effects of frequency specific microcurrent applications on tendon, skin, bone, cartilage, and muscles (7-18). Tendons for example, do not involve blood vessels like muscles. Instead, oxygenation plays one of the most important roles in the healing process. Arteries and veins become smaller and smaller as they get closer to the  periphery andreservation of the healthy microcirculation can be problematic after an Achilles tendon injury. ‍

Studies have shown that microcurrent technology:

• Boosts tissue oxygenation
• Decreases oxidative stress
• Maintains cellular integrity to minimise tissue damage

It therefore can help energy metabolism, increases tissue contractility, augments protein synthesis, enhances tissue regeneration and play a major role in wound healing (12-18). 

Key takeaways

All the studies referenced show that NuroKor technology can be a useful tool to play an important role in Achilles tendon injuries and  help the healing process of the ruptured tissue. Future studies will further develop and confirm these initial findings, as well to optimise dosage and frequency protocols. To learn more about NuroKor and the three bioelectrical modalities used in our technology, read our BioElectrical Clinician Explainer.

About NuroKor

Founded in 2018, NuroKor is a business committed to the development of bioelectronic technologies. NuroKor develops and formulates programmable bioelectronic software for clinical and therapeutic applications, in a range of easy to use, wearable devices. It provides the highest-quality products, delivering personalised pain relief and recovery support and rehabilitation to patients.

References:

1. Costa M et al, UK Study of tendo Achilles Rehabilitation multicentre randomised clinical trial (UK STAR), University of Oxford, 2020  
2. Eckenrode BJ, Stackhouse SK. IMPROVED PRESSURE PAIN THRESHOLDS AND FUNCTION FOLLOWING NOXIOUS ELECTRICAL STIMULATION ON A RUNNER WITH CHRONIC ACHILLES TENDINOPATHY: A CASE REPORT. Int J Sports Phys Ther. 2015 Jun;10(3):354-62. PMID: 26075151; PMCID: PMC4458923.
3. Lui PPY. Tendinopathy in diabetes mellitus patients-Epidemiology, pathogenesis, and management. Scand J Med Sci Sports. 2017 Aug;27(8):776-787. doi: 10.1111/sms.12824. Epub 2017 Jan 20. PMID: 28106286.
4. Baumbach SF, Braunstein M, Mack MG, Maßen F, Böcker W, Polzer S, Polzer H. Ansatznahe Erkrankungen der Achillessehne : Differenzierte Diagnostik und Therapie [Insertional Achilles tendinopathy : Differentiated diagnostics and therapy]. Unfallchirurg. 2017 Dec;120(12):1044-1053. German. doi: 10.1007/s00113-017-0415-1. PMID: 28980027.
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