Overview
Definition of laser therapy (Low-level laser therapy or LLLT)
Laser therapy is a treatment that involves the use of intense beams of light that cut and destroy.1 Typically, when used on tissues, low-level lasers (LLLT) are employed. These lasers use light energy with a wavelength of 600 to 1000 nm, which is ideal for promoting tissue regeneration, reducing inflammation, and relieving pain.2
Overview of sports injuries
When we talk about sports injuries, we refer to injuries caused during a certain physical activity. These injuries include any condition affecting the musculoskeletal system and are not limited to athletes. The most common injuries typically include sprains, strains, and sometimes tendinitis or bursitis. It is important to note that these injuries, even with appropriate treatment, may require a long period of recovery.3
Importance of effective treatment options in sports medicine
Each injury will have a different type of treatment; however, most mild injuries can be treated with the R-I-C-E method, which stands for Rest, Ice, Compression, and Elevation, and can be done at home. If the injury is severe, you should see a professional. The professional will decide which treatment route to follow, potentially using a cast, splint, or brace, and if necessary, recommend a physical therapist to assist with rehabilitation. In the worst-case scenario, surgery may be required.3
How laser therapy works
Explanation of laser therapy mechanics
The most important factor to consider is the wavelength, as it ensures the absorption of light in the tissue. This wavelength guarantees that light photons can penetrate the skin sufficiently to impact the target chromophores in the cells. About 4-7% of this radiation will be reflected, while the remaining 93-96% will either be completely absorbed or scattered.
The chromophores transform light into non-radiant heat, increasing circulation and promoting various therapeutic effects.4
How it affects cells
Low-level laser therapy (LLLT) directly affects the mitochondria of the cells, which are their "energy factories," causing certain receptors in these cells, called tyrosine kinase receptors, to become activated. This activation triggers a specific cellular pathway (MAPK/ERK) that facilitates increased cell proliferation and tissue repair.5
Low-level laser therapy (LLLT) vs high-intensity laser therapy (HILT)
LLLT reduces pain and improves function in patients. However, HILT, by transmitting a greater amount of energy, is able to stimulate and penetrate more deeply and broadly, significantly reducing pain and inflammation and accelerating recovery more than LLLT.
Therefore, for mild or superficial injuries, LLLT is recommended, while for injuries that cause chronic pain or are very deep, HILT is the better option.6,7
Benefits of laser therapy for sports injuries
Pain relief
This is achieved by stimulating nerve regeneration, relaxing muscles, and reducing inflammation.8
Accelerated tissue repair and reduced inflammation
Lasers can also stimulate tissues, enhancing their regeneration, reducing inflammation and swelling, and restoring normal cellular function.9
Improved circulation
The laser can improve circulation by increasing vasodilation, boosting blood flow, and allowing more oxygen to reach the cells. It can also stimulate the lymphatic system, helping to remove accumulated fluids (oedema).10
Non-invasive and drug-free
Lasers are completely safe, non-invasive, and drug-free.11
Common sports injuries treated by laser therapy
Muscle strains and sprains
Strains are injuries to the muscles or the connective tissue between the muscle and the bone. On the other hand, sprains always affect the tissue responsible for connecting two bones together.12
Tendon injuries
Tendons are structures responsible for connecting all the muscles in your body, making them particularly susceptible to all kinds of injuries and disorders that become more common with age. The most common tendon injuries include:13
Tendon strains: These result from tearing, twisting, or pulling on the tendon and often occur in the legs and arms.13
Tendinitis: This occurs with ageing or due to repetitive activities or overtraining. As a result, the tendons become inflamed. The most common types of tendinitis include:13
- Patellar tendinitis: An injury that occurs in the tendon connecting the kneecap to the tibia
- Rotator cuff tendinitis: An injury affecting the shoulder muscles
- Tennis elbow (lateral epicondylitis): An injury that occurs when the tendons around the outer part of the elbow are microscopically torn
Tenosynovitis: More common in the hands and feet, it occurs when tendinitis is accompanied by inflammation of the tendon sheath. The most common types of tenosynovitis include:13
- De Quervain's tenosynovitis: Causes swelling in the thumb. It often occurs due to excessive use, repetitive gripping, or conditions such as arthritis
- Trigger finger or trigger thumb: This also occurs in the thumb, in this case when it gets stuck in a bent position
Other tendon injuries include:
Joint injuries
Joints are structures where two bones connect to each other. Joints are made up of ligaments, tendons, cartilage, and synovial fluid. If any of these parts have problems, the joints fail. Injuries are often due to overuse and wear and tear from ageing.14
Some of the most common conditions and injuries affecting the joints include:
- Bursitis
- Degenerative diseases of the bones and joints, such as osteoarthritis
- Dislocations
- Fractures and fissures
- Gout, a form of arthritis
- Loss of bone density (osteoporosis)
- Rheumatic conditions
Soft tissue injuries
Soft tissues can also be damaged as they are found in muscles, ligaments, and tendons.15
The most common example is ligament tears which occur when they are stretched and then suffer an impact or trauma. For example, when you run and accidentally twist your ankle. 16
Effectiveness of laser therapy
Overview of clinical studies supporting the effectiveness of LLLT
Most studies have shown positive results, although it is also true that some inconsistency is observed in the choice of laser standards, such as wavelength, energy consumption, laser contact surface, and treatment duration. Nevertheless, most experts agree that LLLT is a useful therapeutic method with great potential for future improvement. Examples of successful studies include:17
Chang et al. demonstrated an improvement in the recovery of closed bone fractures in the human wrist and hand.
Badawy et al. showed through their research that laser therapy is highly effective in aiding the recovery of flexor tendon repair in the hand.
Tezcan et al investigated the effect of LLLT on patients with carpal tunnel syndrome and demonstrated an improvement in the patient's condition, mainly because LLLT helped with nerve repair and increased vascular flow.
Discussion of its use in combination with other therapies
It has been shown that low-level laser therapy (LLLT), combined with certain therapeutic exercises, such as eccentric exercise or isometric contraction, is more effective in treating tendinopathies than many other current therapies.18
It has also been demonstrated that exercise therapy combined with high-intensity laser therapy can decrease pain and improve function in patients with osteoarthritis.19
Limitations and considerations
It is important to consider that although laser therapy offers many benefits, it also presents a series of limitations.20
Pregnancy: Like other therapies, the use of lasers is not recommended during pregnancy. While there is no evidence to support the avoidance of lasers in areas distant from the uterus, it is a risk that is advisable to avoid.
Epileptic Seizures: Epileptic seizures can be triggered when visible red light is in the range of 5–10 Hz. Therefore, it is important to exercise extreme caution when treating individuals with epilepsy.
Thyroid Gland: The thyroid gland is very delicate, and it is advisable not to use lasers in areas close to this gland. Studies in rats have demonstrated a strong relationship between laser use and an increase in thyroid-stimulating hormone (TSH).
Children: Although it has not been demonstrated, there is concern about how lasers could affect growth plates in children.
Cancer: For now, laser therapy is discouraged in patients undergoing treatments involving any form of radiation.
Diabetes: There is still some debate regarding diabetes as a contraindication for the use of laser therapy. More studies are needed to confirm this.
Laser therapy procedures
What to expect during a session
In the case of receiving LLT, your specialist will wear special goggles to protect their eyes and will touch the area of your injury with light-emitting diodes. The sensation is usually completely painless. After this, in some cases, they will ask you to perform some gentle exercises to assess the improvement process.21
Duration and frequency of treatments
Contact with the diodes lasts a few seconds. The duration and frequency of the treatment as a whole will largely depend on the type of injury and its severity. This study suggests that LLT therapies can be administered for 10 to 15 seconds. For example, laser irradiation was administered for 10 to 15 seconds in each area over a period of 5 to 10 minutes in a single weekly session. Additionally, the average number of treatments for 22 patients was 4.1 times.22
Safety and potential side effects
Although laser therapy is safe, non-invasive, and very effective, there are certain risks associated with its use:23
- Skin irritation or burns due to exposure to the laser
- Injuries or loss of vision from contact with the laser
- Increased risk of skin cancer with frequent exposure to the laser
- Possibility of infection if the laser is applied to an open wound or infection
Summary
Laser therapy is very effective for enhancing tissue healing, reducing inflammation, and alleviating pain. It is effective for many sports injuries, such as sprains and tendinitis.
The benefits include pain relief and accelerated healing, supported by clinical studies, especially with therapeutic exercises. However, it may not be suitable for pregnant individuals, those with epilepsy, or cancer patients.
During treatment, practitioners use light-emitting diodes on the injury site, and it generally does not cause any pain. The duration of the sessions varies based on the severity of the injury, usually lasting from 10 to 15 seconds per area. Although it is a generally safe therapy, it is important to consider potential side effects.
References
- Laser therapy: medlineplus medical encyclopedia [Internet]. [cited 2024 Oct 4]. Available from: https://medlineplus.gov/ency/article/001913.htm
- Low level laser therapy - an overview | sciencedirect topics [Internet]. [cited 2024 Oct 4]. Available from: https://www.sciencedirect.com/topics/nursing-and-health-professions/low-level-laser-therapy#:~:text=Low%2Dlevel%20laser%20therapy%20(LLLT)%20involves%20the%20use%20of,reduce%20inflammation%2C%20and%20relieve%20pain.
- NIAMS. NIAMS Health Information on Sports Injuries [Internet]. National Institute of Arthritis and Musculoskeletal and Skin Diseases. 2018. Available from: https://www.niams.nih.gov/health-topics/sports-injuries
- Ash C, Dubec M, Donne K, Bashford T. Effect of wavelength and beam width on penetration in light-tissue interaction using computational methods. Lasers Med Sci [Internet]. 2017 [cited 2024 Oct 4];32(8):1909–18. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5653719/
- Rola P, Włodarczak S, Lesiak M, Doroszko A, Włodarczak A. Changes in cell biology under the influence of low-level laser therapy. Photonics [Internet]. 2022 Jul [cited 2024 Oct 4];9(7):502. Available from: https://www.mdpi.com/2304-6732/9/7/502
- D.C DBW. High intensity laser therapy vs low intensity laser therapy [Internet]. In Motion Pain Solutions. 2021 [cited 2024 Oct 4]. Available from: https://inmotionpainsolutions.com/blog/high-intensity-laser-therapy-vs-low-level-laser-therapy/
- Ordahan B, Yigit F, Mülkoglu C. Efficacy of low-level laser versus high-intensity laser therapy in the management of adhesive capsulitis: a randomized clinical trial. Saudi J Med Med Sci [Internet]. 2023 [cited 2024 Oct 4];11(3):201–7. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10393096/
- admin. Does laser therapy really work for pain? [Internet]. OC Wellness Physicians Medical Group. 2021 [cited 2024 Oct 4]. Available from: https://ocwellnessphysicians.com/does-laser-therapy-really-work-for-pain/
- Hirsch A. Delaware Back Pain. 2020 [cited 2024 Oct 4]. How can laser therapy help treat inflammation? Available from: https://www.delawarebackpain.com/2020/05/22/how-can-laser-therapy-help-treat-inflammation/
- Huntington Beach PT Specialists [Internet]. [cited 2024 Oct 4]. Laser light therapy - huntington beach pt specialists - huntington beach ca. Available from: https://www.hbpts.com/laser-therapy/
- Laser treatment - rxr rehab physical therapy [Internet]. 2021 [cited 2024 Oct 4]. Available from: https://rxrhealth.com/laser-therapy/, https://rxrhealth.com/laser-therapy/
- Mayo Clinic [Internet]. [cited 2024 Oct 4]. Muscle strains - Symptoms and causes. Available from: https://www.mayoclinic.org/diseases-conditions/muscle-strains/symptoms-causes/syc-20450507
- Cleveland Clinic [Internet]. [cited 2024 Oct 4]. Tendon: function, anatomy & common injuries. Available from: https://my.clevelandclinic.org/health/body/21738-tendon
- Dignity Health [Internet]. [cited 2024 Oct 4]. Common joint conditions symptoms & causes | dignity health. Available from: https://www.dignityhealth.org/conditions-and-treatments/orthopedics/common-joint-injuries-and-conditions
- Soft-tissue injuries [Internet]. 2021 [cited 2024 Oct 4]. Available from: https://www.hopkinsmedicine.org/health/conditions-and-diseases/softtissue-injuries
- Orthopedics | ligament tears causes & symptoms | corewell health [Internet]. [cited 2024 Oct 4]. Available from: https://www.beaumont.org/conditions/ligament-tears
- Mansouri V, Arjmand B, Rezaei Tavirani M, Razzaghi M, Rostami-Nejad M, Hamdieh M. Evaluation of efficacy of low-level laser therapy. J Lasers Med Sci [Internet]. 2020 [cited 2024 Oct 4];11(4):369–80. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7736953/
- Lyu K, Liu X, Jiang L, Chen Y, Lu J, Zhu B, et al. The functions and mechanisms of low-level laser therapy in tendon repair(Review). Front Physiol [Internet]. 2022 Feb 15 [cited 2024 Oct 4];13:808374. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8886125/
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