Tendonitis is an inflammation or a slight damage to the tendon, that it swells. Tendons are a type of connective tissue that connects muscles to bones and, therefore, enables movement. It usually arises from repetitive strain or overuse injuries in areas such as the shoulders, elbows, and knees. People who have complained of this condition usually have pain and tenderness around the joint, especially where the tendon attaches to the bone. Tendonitis can be an acute or chronic problem.¹

Symptoms and causes of tendonitis

Tendonitis is typically described as pain directly in the location of a tendon, stiffness and immobility, sometimes accompanied by grinding or popping within a joint. Tendonitis usually affects the tendons at the base of the thumb, elbow, shoulder, hip, knee, and Achilles. Symptoms can be mild or severe; onset may be slow and gradual or sudden, for example, if calcium has built up at the site of an injury and forms a painful lump that feels hard to the touch. Tendonitis can result from overuse, repetitive motion, sudden injury and using certain medications. It can also be the outcome of an ongoing health disorder like diabetes, rheumatoid arthritis, gout, osteoarthritis, or even an infection. Other risk factors include repetitive activities, such as gardening or woodworking, sporting activities, poor posture, muscle-weakening conditions, and age, which tends to appear after the age of 40 due to a decrease in tendon elasticity and heightened vulnerability to injury.¹

Overview of treatment options

There are mainly two major steps involved in the treatment of the tendonitis illness. These include icing the affected area, avoiding activities which increase the symptoms, resting the injured site, and finally, taking over-the-counter anti-inflammatory medications. If there is no improvement in the symptoms after three weeks, then a health practitioner may suggest other treatment options. These include corticosteroid injections to rapidly reduce inflammation and pain; and physical therapy, including range of motion exercises, splinting, and progressive loading of the tendon to regain mobility and strength. Physical therapy may also address mobility deficits in other joints contributing to the condition. Surgery rarely is required and is reserved for those severe cases unresponsive to the other treatments.¹

Low-level laser therapy has been used for over three decades as a non-pharmacological intervention in painful musculoskeletal disorders such as tendinopathy. Laboratory studies consistently report that low-energy laser irradiation can alter cellular processes, promoting anti-inflammatory effects and an increase in collagen production, thus enhancing healing. A translation of these positive findings to clinical trials has been variable; some report benefits, while others do not. The systematic reviews also identify the dose-dependent effect of LLLT-that studies with suggested dosages tend to have better results. Since then, dosage guidelines have been developed by the World Association for Laser Therapy, and the importance of proper dosage to ensure successful treatment has been emphasised.²

What is laser therapy?

Low Level Laser Therapy, also referred to as Low Level Light Therapy or Photobiomodulation, is a form of low-intensity light therapy. The effects are photochemical, not thermal. The light provokes biochemical changes in cells, where photons are absorbed by cellular photoreceptors and initiate chemical reactions.³

A laser is a device that emits light through the process of optical amplification, which is based on the stimulated emission of electromagnetic radiation. This focused light can pass through tissues and initiate biological activity, a process that is known as "laser biostimulation”. The most common wavelengths in lasers for treatment lay in the red to near-infrared spectrum between 660-905 nm, which is effective in pain reduction, inflammation reduction, and assistance in tissue repair. Low-level laser therapy makes use of lasers or LEDs within the same power range, 10 mW to 500 mW, applied briefly to injury sites to stimulate the healing process without invasive methods.³

Types of lasers used in therapy

The International Engineering Consortium has categorised lasers into four classes depending on the severity of the danger they pose to the eyes. Class 1/1M lasers, which are used in CD players, for instance, are classified as harmless whereas Class 2/2M lasers, used as laser pointers pose a low risk. The medium-power Class 3R/3B lasers are applied in minor surgery and skin treatment, including LLLT, and also applied in CD/DVD writers. These high-power Class 4 lasers are used for several medical applications, including eye and skin treatments. LLLT uses Class 3B lasers or LEDs; because these are of much lower intensity, light treatments that are noninvasive, their use extends to the treatment of tendonitis to promote healing and resolve inflammation.³

LLLT in the treatment of pain

LLLT is effective in a wide range of acute orthopaedic conditions including sprains, strains, post-surgical pain, whiplash, back pain, radiculopathy and tendinitis. The benefit is increased in chronic conditions such as osteoarthritis, rheumatoid arthritis, frozen shoulder and fibromyalgia. It is useful in a range of problems which include carpal tunnel syndrome, tendinopathy, plantar fasciitis and chronic regional pain syndrome. LLLT is useful in dental pain conditions, including orthodontic and wisdom tooth surgery. It is also effective in neuropathic pain conditions, such as post-herpetic neuralgia and diabetic neuropathy. The wide range of applications indicates that several mechanisms contribute to the pain-relieving effect.³

Benefits of laser therapy for tendonitis

Laser therapy has many benefits in the treatment of tendonitis by the use of mainly two types: low power laser therapy and high power laser therapy. The low power laser therapy, less than 0.5 watts, speeds up the recovery process along with eccentric exercises, particularly in chronic Achilles tendinopathy. High power laser therapy is stronger, and thus can penetrate deeper tissues within a very short time and cause heating up; therefore, it acts to diminish pain effectively in shoulder pain, knee osteoarthritis, and chronic back pain. It enhances the repair of tissues by improving metabolism and blood flow, and helping in the resorption of edema. HPLT stimulates mitochondrial activity, DNA, RNA, production of ATP, and hastens the cellular healing process; therefore, it can be considered better than usual physiotherapy techniques, such as ultrasound or heating.⁴

Effectiveness compared to other treatments

Low-level laser therapy seems to be one of those potentially safe, non-invasive treatments for tendinopathy and plantar fasciitis, with no adverse side effects, as opposed to the potentially highly dangerous NSAIDs for severe cardiovascular and gastrointestinal complications. Exercise therapy is traditionally established in the case of tendinopathy, but no single treatment has been shown superior. LLLT appears unique because it reduces pain and inflammation by stimulating tissue repair mediated by mechanisms that involve increased ATP production and modulation of reactive oxygen species. Clinical trials have, however, yielded diverse results, with most of these results perhaps stemming from the heterogeneity in parameters of LLLT itself; these suggest a dose-response relationship is important in making LLLT more effective against other interventions.⁵

Summary

Laser therapy has a lot of advantages in treating tendonitis: repair of tissues, reduction of inflammation, and pain relief without invasive procedures or harmful side effects. Both the low-level laser therapy treatment and the high-power laser therapies are effective, with the latter reaching deeper tissues to enhance the process of healing even more. In both chronic and acute cases, both are quite effective. However, such laser treatments should not be instituted without professional advice to ascertain whether the modality is suitable for the specific condition of the patient. This is in line with the planning of an individualised course of treatment for optimisation of delivery. Generally, laser therapy is a relatively non-invasive and harmless technique that holds much promise for accelerating recovery and return of function in tendonitis patients. To this effect, it may reduce pain and inflammation, and it may also trigger the repair of tissues as part of alternative/complementary management against more conventional ones using physical therapy and medication.