Questions and Answers for Low‐Level Laser Therapy
What is low‐level laser doing?
Low‐level laser therapy is a therapeutic strategy that addresses a particular medical ailment in a diverse
and multifactorial manner. Laser therapy is not a unilateral tool, it does not simply suppress pain nor
does it just increase range of motion, it restores functionality and improves quality of life by resolving all
underlining causes. For instance, shoulder pain generally arises from a single traumatic event, and as a
means to prevent aggravation of the injured tissue your body will restrict movement, decreasing
neuropeptide release and restricting blood and oxygen flow along the injured site. Laser therapy, by
stimulating both the nervous system and site of tissue injury, has been clinically proven to suppress
inflammation, increase oxygen and blood flow, promote muscle calcium uptake, and increase
neurotransmitter release. By addressing the injury with a diverse tool it is possible to resolve the
condition more effectively by suppressing not one contributor but all contributors.
How does it work?
Low‐level laser therapy operates under a principle of science known as photochemistry, and as the
name implies, is the modulation of chemical and biochemical reactions through the absorption of
photons, or light energy. Housed within the mitochondria, the cell energy manufacturer, are receptors
capable of absorbing distinct parameters of light. Think of these receptors like any drug receptors.
When we consume a prescription medication, the compound is absorbed by the body and it locates a
particular receptor, and based upon its molecular design, will bind to that receptor. Once the drug binds
a secondary reaction inside the cell takes place. A similar mechanism is observed when exposing the
body to a particular color of light. During a treatment the light will penetrate the skin and is absorbed
by this receptor within the mitochondria. Receptor stimulation with light promotes energy production,
biochemical reactions, protein and growth factor synthesis, cell growth and proliferation, enhanced
blood and oxygen flow, and prevents cell death. When one understands a wound environment, having
the capability to address multiple cellular impairments with one therapeutic modality enhances
recovery and restoration in the quality of life.
How does laser therapy strengthen muscle?
Skeletal muscle tissue is capable of aerobic and anaerobic respiration, requiring glycolysis, the Kreb
cycle, and oxidative phosphorylation to produce Adenosine Triphosphate (ATP). Utilizing these complex
pathways demands a regular supply of oxygen and nutrients, and as we participate in extensive exercise
these components can become depleted. When a muscle contracts the central stimuli originates from
the central nervous system transitioning to the peripheral nervous system which innervates the target
muscle promoting contracture via the release of a neurotransmitter. Subsequent the release of
neurotransmitters a secondary reaction cascade is stimulated which promotes skeletal muscle calcium
influx inducing muscle contracture. An integrative network of neurons and biochemical pathways are responsible for muscle strength and integrity; ultimately, any modulation in one of these pathways
could dramatically impact functionality. The application of low‐level laser therapy has been clinically
proven to not only increase range of motion in patients suffering with acute and chronic pain but also
reduced the overall pain experienced by the patient after one application. Delivering specific
parameters of light can increase ATP production, promote calcium influx, and support proper nervous
system function and neurotransmitter release. As a simple acute injury can modulate muscle function
resulting in a chronic pain state, the application of laser can support muscle strength and improve range
of motion by preventing tissue plasticity.
How can low‐level laser therapy penetrate through clothing?
The application of a line‐generated beam delivered by a low‐level laser device emits approximately 45
billion photons every second. And although clothing material will demonstrate some degree of photon inhibition, the reaction at the cellular level is truly a 1 to 1 reaction, requiring only one photon to excite
one electron positioned within the photoreceptor. Although producing a clinical outcome necessitates
more than one photon, clothing will not serve as a completely restrictive barrier therefore clothing will
enable a clinically significant amount of photons to penetrate.
Why can’t I feel anything during a treatment?
Low‐level laser therapy does not deliver a significant amount of energy therefore no friction‐like
reaction occurs which produces heat. Further, the type of energy delivered does not vibrate or oscillate
the cell therefore no photo‐acoustic sensation is experienced. Low‐level laser therapy operates at the
sub‐atomic level stimulating electrons that are positioned around atoms, and subatomic stimulation is
responsible for altering photoreceptor behavior and conversely cell metabolism. Since the biochemical
response to laser therapy primarily depends on the color of light and not the output energy, the
sensation experienced is similar to what is felt when consuming a prescription medication, none.
Millions of biochemical reactions are taking place at this very moment without any comprehension or
recognition, and low‐level laser therapy is applied to stimulate or enhance naturally occurring reactions,
which are struggling to proceed or being overexpressed in an injured state. Even though laser has
always been associated with burning and tissue destruction, low‐level laser therapy on the other hand
operates under very similar parameters to a prescription medication, producing no macroscopic
sensation but directly impacting how the body’s cells function and behave.
How can a response be produced in a matter of a few seconds?
The body is principally a collection of molecules organized founded upon their unique chemical charges
and disposition to participate in a reaction. The manner in which a chemical reaction proceeds depends
on atomic collision and if that encounter participates at the right force while having proper electron
orientation. Since low‐level laser therapy is responsible for modulating the energy state in which
electrons reside an immediate increase in the rate at which the photoreceptor functions coupled with
an elevation in energy production is observed.
Why aren’t other doctors using this technology?
Low‐level laser therapy is not a new technology; in fact, light‐based therapy dates back as far as 1,500
BC when Egyptian cultures built solariums at the top of mountain ranges to harness ultraviolet light to
treat certain skin disorders. Laser therapy has been studied extensively starting in the early 1960’s and
has earned over 1,500 peer reviewed publications. The one limitation of this application has always
been the delivery mechanism, in order to generate a coherent light source in which the photons move in
parallel with each other a small dot was required, obviously not practical within a clinical setting.
Although an extensive body of research highlighted the efficacy of this technology it was simply not
practical. However, in 1998 Erchonia Corporation designed the first line‐generated coherent laser light
source which enabled clinicians to treat with an appropriate photon configuration over an acceptable
surface area. Although this innovative mechanism provided functionality to low‐level laser therapy the
science in which it operates under is relatively new and presently not taught within health care related
institutions. Everyday more and more physicians are observing the benefits of this technology, and as
new studies are published which illustrate the therapeutic benefit of this application more physicians
are embracing this technology. Presently, laser therapy is used across a wide‐assortment of medical
disciplines to treatment a diverse arrangement of medical ailments. It is through science that laser
therapy will prevail.
Why not use a laser pointer?
Although a laser pointer is an actual laser perhaps possessing the correct wavelength there are power
considerations that are important. Laser therapy is very similar to the parameters required for drug
success. For instance, when one consumes a medication it is the molecular structure of the drug that is
the driving factor for therapeutic success. Similar to this notion is the wavelength or color of the laser
device, if the color is not correct therapeutic efficacy will be lost. Another component of a medication
that must be satisfied is dosage, in order to produce an outcome the dosage must be correct, too little
there is no response too much an adverse event can be provoked. Similarly, laser therapy must be
delivered at the appropriate dosage and a laser pointer is does not provide enough energy, conversely
too much power can induce an inhibitory or damaging effect. Laser therapy must fulfill stringent
parameters to display a clinical response.
How far does laser penetrate?
Next time you are enjoying a sun filled day, look up at the sun and close your eyes, the world of red light
you perceive an no other color is the penetration of red photons being interpreted by the light receptors
present within your eye. Although this is an elemental description it clearly illustrates the penetrative
capacity of red photons. A vast amount of clinical data also supports the manner in which various
wavelengths can penetrate the skin barrier and provoke a biochemical reaction. Numerous peer‐
reviewed published articles highlight that subsequent to laser therapy the treatment group receiving
light therapy demonstrate marked improvement when compared with the placebo “sham device”
treated group. Further, in vivo or ex‐in vivo studies have quantified the amount of light that can
penetrate various degrees of skin thickness and other tissue structures. If laser therapy was unable to
enter the skin barrier the earliest clinical trials would have demonstrated an ineffective remedy, but as
this technology expands and a greater collection of patients benefit, it is clear that the argument
pertaining to depth of penetration is not warranted. On a separate note, subsequent to laser
histological evidence reveals an upregulation of intercellular communicators that can promote a
response in non‐laser stimulated cells implying that the penetrative effect may be independent of the
photon itself. No matter the degree of complexity associated with laser therapy regarding its acute and
systemic effect, what is well established is that laser therapy, within a proper clinical trial model reveals
consistent positive outcomes compared to a placebo‐controlled group receiving a sham treatment.
How long does it last?
Low‐level laser therapy is a multifactorial approach and when partnered with neuromusculoskeletal
techniques the therapeutic strategy can potentially address the underlining condition and results can
last until the tissue is re‐aggravated. Clinical studies demonstrate that the positive outcomes associated
with laser therapy are immediate and can last many weeks but like many therapies laser requires
numerous treatments to effectively resolve the underlining etiologies responsible for producing pain.
Treating the point of injury can dramatically improve blood and oxygen flow, downregulate pro‐
inflammatory cytokines, and promote muscle activation and strength, but if the injury is not resolved
inevitably these beneficial components will become overwhelmed and the pain will return. Coupled
with preventive care a treatment series with low‐level laser therapy delivered by a trained professional
can generate long‐term results.
When do you use it?
Tissue plasticity associated with neuro‐plasticity is believed to be the major contributor of an acute
condition transitioning into a chronic state; therefore, laser therapy should be applied immediately
following an acute injury. Early therapeutic intervention can prevent the deactivation of agonist muscle
tissue, restore range of motion, and suppress injury progression. Stimulation of along the injury site as
well as the muscle tissue adjacent and the nervous system innervating the extremity can ensure the
damage is approach from an all‐encompassing perspective enhancing a patient’s recovery. Laser
therapy represents a therapeutic model that can serve both an early and late intervention role, but for
long‐term benefits and prevention of an injury transforming into a chronic state, laser therapy should be
applied early and often.
Why do you not just treat the acute point?
A wound or injury is not an acute disorder, it is representative of broader deficiencies and therefore the
therapy should respect the diverse pathophysiology. Healing requires an orchestra of proteins and cells
functioning in a coordinated effort to mend the impaired tissue, an effort incorporating multiple bodily
systems. For instance, proper wound closure requires the release of neuropeptides and proper skeletal
muscle function necessitates the release of the neurotransmitter acetylcholine. Without stimulation or
activation of the central and peripheral nervous system a major factor for injury repair is disregarded.
Understanding the diverse mechanism low‐level laser therapy is applied at both acute and systemic
regions to activate all bodily systems participating collectively for proper wound or injury healing.
Why not receive just one treatment
Even though one treatment can impact cell proliferation, protein synthesis, increase blood and oxygen
flow, and activate as well as strengthen muscle tissue if the required amount of time for complete
resolution these outcomes will only be temporary. With any condition a multifactorial deficiency is
often responsible for the clinical pain and therefore a multifactorial therapeutic approach is required,
and if one aspect is addressed leaving many more untreated, then complete resolution is not possible.
This principle is common across all disciplines of medicine, if a patient suffers from a bacterial infection;
the ingestion of one anti‐bacterial tablet will have some benefit but will have no means of eradicating
the entire bacterial colony. Although the literature supports that one treatment of laser therapy can
generate a significant improvement in pain for long‐term pain relief multiple treatments are essential.