The Science

What is Laser Therapy?

Laser Therapy is known by many terms, including cold or low-level laser therapy (LLLT). Recently, experts have chosen photobiomodulation therapy (PBMT) as a more accurate term that describes the therapeutic use of red and near-infrared wavelengths of light energy from laser OR light emitting diodes (LEDs) that interact with photoreceptors to produce photochemical reactions that have a positive effect on cellular metabolism and recovery from damage and inflammation.

BIOFLEX® is the only laser therapy company that utilizes powerful Class 3b lasers together with large surface arrays of bicolour LEDs that affect a large volume of circulating blood as well as underlying tissues resulting in both a powerful systemic and direct photobiomodulation effect. The overall clinical effect of targeting both the injured/diseased tissues as well as the surrounding circulatory system is an unsurpassed accelerated healing response and decrease in pain, inflammation, edema and associated symptoms.

Light Spectrum in Laser Therapy

The effectiveness of wavelengths of light with respect to photobiomodulation therapy can be characterized by the action spectra of the target photoacceptors (e.g. cytochrome c oxidase), that determine the positive biological responses such as increased metabolism, cellular regeneration and immunomodulation. The most clinically effective wavelength ranges are in the red (630-680 nm) and near infrared spectra (810-840 nm). Wavelength is one critical parameter of light among other factors such as dosage or energy density (J/cm2), treatment time and light delivery in pulses (cycles per second or Hz) in determining the efficiency of absorption, depth of penetration and ultimately the clinical outcomes. The effects of photobiomodulation are cumulative and can be clinically evident immediately after treatment or over a period of days.

Red Light

Since the introduction of the He-Ne laser (632.8 nm) in the 1960s, the positive effects of red light wavelengths (λ = 630-680 nm) have been established both in vitro and human clinical trials. These wavelengths are highly absorbed by cytochrome c oxidase, one of the terminal enzymes in the electron transport chain responsible for the creation of ATP. Cells and tissues under metabolic stress due to injury or disease will repair and recover much faster when exposed to these red wavelengths as a direct result of increased ATP production and increased cellular metabolism.

Red wavelengths are also absorbed to some degree by other photoacceptors in the skin including hemoglobin and melanin which limits the effective depth of penetration to the subcutaneous regions of the body (approximately 5-10 mm). Other wavelengths like violet and blue are so highly absorbed by skin photoacceptors that they barely penetrate the skin (1-2 mm) and thus are not used in Laser Therapy with the exception of treating superficial skin conditions like acne.

Red wavelengths principally in the 630-680 nm range are very beneficial for treating conditions that are relatively superficial such as subcutaneous bursitis, skin conditions like acne, psoriasis, hair loss and eczema as well as wounds and chronic ulcers. The large network of capillaries located in the subcutaneous region will also absorb red wavelengths resulting in a powerful immunomodulating effect by the activated white blood cells, stem cells and platelets. This is called a systemic or remote effect and it produces an anti-inflammatory and healing effect that is circulated by the activated white blood cells to injured and diseased tissues deep to the treated area. Even though red light does not penetrate deeply, it can still be a very powerful healing wavelength for deeper tissues provided the dosage of light is adequate. The more blood that is stimulated the stronger the systemic effect of photobiomodulation.

Infrared Light

Near Infrared wavelengths are also known to be absorbed by cytochrome c oxidase and other photoreceptors that result in positive effects on cellular physiology. Tiina Karu was the one of the key researchers to establish the photoabsorption spectra of these photoacceptors as well as the ranges of wavelengths that result in optimal photobiomodulation. She observed near infrared wavelengths in the ranges of 810-840 nm were most active, making them more effective for deeper lying injuries and conditions associated with musculoskeletal conditions.

These near infrared wavelengths are much less absorbed by hemoglobin and other photoacceptors that prevent light from penetrating more deeply. As a result, light in the range of 810-840 nm are considered to be the most transparent of the wavelengths used in photobiomodulation therapy allowing for much deeper effective penetration of several cm. The actual clinical effective depth of penetration varies as a result of factors like skin colour, tissue density, power, treatment time and using contact technique.

Tissues like bone, tendon, muscle, adipose and ligament vary with respect how much light can effectively penetrate and accumulate to a dosage high enough to result in a photobiomodulation effect. When trying to elicit a direct photobiomodulation effect on these types of tissues, near infrared wavelengths (810-840 nm) are the most effective and are the “go to” wavelength range to heal these deeper tissues. Using greater power is one way to increase the dosage more quickly in these deeper tissues. However, as power increases so does the potential for an inhibiting thermal effect. Of course higher power also means shorter treatment times which results in fewer target photoacceptors being stimulated. Research has shown longer illumination times result in a greater therapeutic effect. The consensus on how to achieve an optimal photobiomodulation healing effect is a balance of high enough power with longer treatment times.

Class III vs Class IV Lasers

Class 3B

 5-500 mW Athermal Lower Energy and longer treatment duration optimizes healing and anti-inflammatory effects.

Class IV

 >500 mW Thermal High energy and longer wavelengths result in tissue heating and less penetration.

The medical subject headings (MeSh) for Laser Therapy is now called photobiomodulation therapy (PBMT). Light emitting diodes (LEDs) and other sources of light have been proven to be clinically effective so referencing only lasers is not accurate anymore. The definition of PBMT mentions that if lasers are used they must be less than 500 mW to avoid a thermal reaction and inhibition of healing. Thus, any single laser diode with the goal of photobiomodulation should be a Class 3B when contacting the skin to ensure optimal penetration and provide enough stimulatory healing energy but not cause thermal tissue damage.

There is much confusion when Class 4 lasers are used for rehabilitation and are marketed as photobiomodulation therapy. Class 4 Laser Therapy (known as high intensity laser therapy or HILT) generally targets water to heat tissues resulting in a temporary analgesic effect but not a photobiomodulation effect that stimulates healing. There is no MeSh term for HILT as it is poorly researched.

The most common wavelength for Class 4 Laser therapy is 980 nm as it is highly absorbed by water molecules resulting in heat build-up – similar to far infrared lamps used to warm food at a restaurant. The power is so high that to avoid burns the laser diode cannot directly make contact with the skin and must be constantly moved. The therapeutic effect is analogous to using a deep heating pad.

Sometimes Class 4 Laser therapy uses red of near-infrared wavelengths similar to that used in PBMT. In this case a very wide beam creates a large surface area which is held a distance away from the skin along with constant movement to avoid burns. This results in similar power densities (mW/cm2) and dosages used for photobiomodulation with Class 3B or LEDs but up to 85% of light is reflected. Thus, very little light is left to enter the skin causing poor tissue penetration. Interestingly, nearly all PBMT clinical research references the use of the contact technique where Class 3B lasers or LEDs touch and push into the skin in order to decrease reflection and maximize light penetration. This can never be achieved with Class 4 laser diodes.

BIOFLEX Laser Therapeutic Platforms

The therapeutic effects of Laser Therapy at the cellular level have proven to increase ATP levels and DNA synthesis and are specific to enhance mitochondrial membrane potential and function. The light emitted using the various laser therapy systems stimulate the photochemical reactions within the cells supporting mitochondrial activities. This can create beneficial changes in cell behavior and accelerate the natural healing process. Mitochondria contain photoreceptors that absorb the photons from light and convert these into ATP – energy that can be utilized to stimulate cellular activities and biological processes. Proper mitochondrial function and ATP production are critical to the process of neuro-protection modulation, regeneration, cognitive enhancement, and the prevention and alleviation of a number of other neurological pathologies. Laser Therapy is effective in:

Musculoskeletal Injuries

The most common applications are muscle strains, ligament sprains, tendinopathies, cartilage tears bursitis and other injuries to the musculoskeletal system. Whether it’s a sports injury, overuse condition, or an accident, the goal of treatment is to accelerate the healing process and decrease symptoms which allows the clinician to initiate manual and exercise therapies much sooner.

Wound Healing

BIOFLEX Laser Therapy has been proven to accelerate surgical wound healing, dermal ulcers, diabetic lesions and all other recalcitrant wounds. This results in increased angiogenesis, neovascularization, collagen secretion and decreased inflammatory exudate and provides epithelization of the wound, improved arterial perfusion and, regeneration of the local and regional tissues.
(Professional Systems)

Arthritis

Chronic progressive forms of joint degeneration can be effectively managed with BIOFLEX Laser Therapy. All of the arthritides from early to late stages will respond to treatment resulting in decreased pain, inflammation, stiffness and edema. Research has even shown repair and regeneration of eroded hyaline cartilage when exposed to Laser Therapy.
(Professional Systems)

Nerve Healing

From diabetic neuropathy to discogenic radiculopathy to carpal tunnel syndrome, BIOFLEX Laser Therapy can accelerate nerve healing and decrease paraesthesia and nerve pain as a result of direct absorption of light. Many peer reviewed clinical trials and lab studies have proven Laser Therapy is an effective therapy for nerve healing and has no known side effects.

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