Like photosynthesis - the correct wavelengths and power of light at certain intensities for an appropriate period of time can increase ATP production and cell membrane perturbation could lead to permeability changes and second messenger activity resulting in functional changes such as increased syntheses, increased secretion and motility changes. Red and near infrared light seem to be the most ideal wavelengths.
Red light acts on the mitochondria and near infrared light on the mitochondria and at the cell membrane. In in-vitro and animal LLLT wound healing studies comparing wavelengths, red consistently is more effective. Shorter wavelengths are not so good, expensive to produce and with poor penetration they are a poor choice. Near infrared light whilst not quite as good do penetrate better than the red wavelengths and are available in higher powers and at low prices . According to live in-vivo experiments at Uniformed Services University Bethesda Maryland (a US military research centre) 810nm is the best penetrating wavelength. It also happens to work well in LLLT nerve regeneration studies they are doing.
An appropriate dose of light can improve speed and quality of acute and chronic wound healing , soft tissue healing, pain relief, improve the immune system and nerve regeneration. Applications with good RCT evidence include Venous Ulcers, Diabetic Ulcers, Osteoarthritis, tendonitis, Post Herpetic Neuralgia (PHN, shingles) & postoperative pain.
To paraphrase NASA research:
“ Low-energy photon irradiation by light in the far-red to near-IR spectral range with low-energy (LLLT) lasers or LED arrays has been found to modulate various biological processes in cell culture and animal models. This phenomenon of photobiomodulation has been applied clinically in the treatment of soft tissue injuries and the acceleration of wound healing. The mechanism of photobiomodulation by red to near-IR light at the cellular level has been ascribed to the activation of mitochondrial respiratory chain components, resulting in initiation of a signaling cascade that promotes cellular proliferation and cytoprotection.”
“ A growing body of evidence suggests that cytochrome oxidase is a key photoacceptor of light in the far-red to near-IR spectral range. Cytochrome oxidase is an integral membrane protein that contains four redox active metal centers and has a strong absorbance in the far-red to near-IR spectral range detectable in vivo by near-IR spectroscopy.”
“ Moreover, 660–680 nm of irradiation has been shown to increase electron transfer in purified cytochrome oxidase, increase mitochondrial respiration and ATP synthesis in isolated mitochondria, and up-regulate cytochrome oxidase activity in cultured neuronal cells.”
“ LED photostimulation induces a cascade of signaling events initiated by the initial absorption of light by cytochrome oxidase. These signaling events may include the activation of immediate early genes, transcription factors, cytochrome oxidase subunit gene expression, and a host of other enzymes and pathways related to increased oxidative metabolism.”
“ In addition to increased oxidative metabolism, red to near-IR light stimulation of mitochondrial electron transfer is known to increase the generation of reactive oxygen species. These mitochondrially generated reactive oxygen species may function as signaling molecules to provide communication between mitochondria and the cytosol and nucleus.”
Therapeutic photobiomodulation for methanol-induced retinal toxicity
LLLT, or Low Level Laser Therapy as it is often called, is the application of red and near infra-red light over injuries or lesions to improve wound / soft tissue healing and give relief for both acute and chronic pain. First developed in 1967, it is now commonly referred to as LLLT.
LLLT is used to : increase the speed, quality and tensile strength of tissue repair; give pain relief; resolve inflammation; improve function of damaged neurological tissue and often used as an alternative to needles for acupuncture.
The red and near infrared light (600nm-1000nm) commonly used in LLLT can be produced by laser or high intensity LED. The intensity of LLLT lasers and LED's is not high like a surgical laser. There is no heating effect.
Below are a few Abstaracts of double blind clinical studies demonstrating the positive effects of LLLT. More abstracts can be viewed on our LLLT Research page .
Pain Scores And Side Effects In Response To Low Level Laser Therapy (LLLT) For Myofascial Trigger Points
E Liisa Laakso Carolyn Richardson, and Tess Cramond
1: Physiotherapy Department, Royal Brisbane Hospital, Brisbane; 2: Physiotherapy Department, University of Queensland, Brisbane; and 3: Pain Clinic, Royal Brisbane Hospital, Brisbane, Queensland, Australia.
A double-blind, placebo-controlled, random allocation study. 41 subjects, chronic myofascial trigger points in the neck and upper trunk region, five treatment sessions over a two week period, All groups demonstrated significant reductions in pain over the duration of the study.
Addressee for Correspondence: E Liisa Laakso BPhty PhD, Physiotherapy Department, Royal Brisbane Hospital, Herston, (Queensland, Australia, 4029.
6/97 Rep. US $8-10-12 copyright 1997 by LT Publishers, , U.K.' Ltd. Manuscript received:January, 1997 Accepted for publication: March, 1997
Diode Laser (LLLT) in Cervical Myofascial Pain: A Double-Blind Study versus Placebo
* F. Ceccherelli, * L. Altafini, * G. Lo Castro, * A. Avila, *F. Ambrosio, and * G. P. Giron
*Institute of Anesthesiology and Intensive Care, University of Padua, and the Associazione Italiana per la Ricerca e, l'Aggiornamento Scientif co, Padua, Italy
Double-blind, pulsed infrared, treatment of myofascial pain in the cervical region. 27 subjects, 12 LLLT sessions, alternate days, at each session the four most painful muscular trigger points and five bilateral homometameric acupuncture points were irradiated with 1J. Pain was monitored using McGill pain questionnaire andScottHuskisson visual analogue scale, pain attenuation in the treated group and a statistically significant difference between the two groups of patients, both at end of therapy and at the 3-month follow-up examination.
Address correspondence and repent requests to Dr. F. Ceccherelli at the Istituto di Anestesiologiae Rianimazione, via C. Battisti 267, 35121 Padova, Italia.
The Clinical journal of Pain 5:301-304 copyright 1989 Raven Press, Ltd., New York
Wave- length Power Energy Density Power Density Energy per point Pulses 904nm 5mW av (25Wpeak) (not given) (not given) 1 J 1KHz x 200nS
Low Level Laser Therapy (LLLT) Of Tendinitis And Myofascial Pains A Randomized, Double-Blind, Controlled Study
Mimmi Logdberg-Anderssont1, Sture Mutzell2, and Ake Hazel3
1: Akersberga Health Care Centre, 2: Danderyd University Hospital, Danderyd, and
3: Vaxholm Health Care Centre, Stockholm, Sweden.
A double-blind study, laser therapy for tendinitis and myofascial pain,176 subjects, 6 treatments during a period of 3-4 weeks.Pain estimated objectively using a pain threshold meter, and subjectively with a visual analogue scale. Laser therapy had a significant, positive effect compared with placebo. Laser treatment was most effective on acute tendinitis.
Addressee for Correpondance, Sture Mutzell, Danderyd University Hospital 5-182 87 Danderyd, Sweden.
03/07 Rep US 10-12-14 , 1997 By LT Publishers, U.K., Ltd., LASER THERAPY, 1997:9: 79-86
Wave- length Power Energy Density Power Density Energy per point Pulses Treatment Time 904nm 8mW av (10Wpeak) 0.5-1.0 J/Cm2 (not given) 1J 4KHz x 180nS 2 mins
Manual therapy is the treatment of choice, but often an electrotherapy is used to augment a hands on approach to aid tissue repair and give pain relief.
Ultrasound is the most commonly used electrotherapy, it is however limited in its effectiveness and limited in its range of applications (ultrasound should not be used over bony prominences, pins, plates and very acute injuries).
Physiotherapists are now turning to LLLT (low level laser therapy) which can be used safely in these areas and finding they are using it more and more. Says Sue Bunn, MCSP, SRP, physio to the British Paragliding Team, " I would not like to be faced with all the acute injuries we see without a laser. Since I've had a laser I can not be bothered with ultrasound and all that gel".This is a comment heard from many physios who find laser easy to learn and simple to use.
LLLT works differently from ultrasound , it works quickly from within the cell and often resolves conditions that have not responded to manual therapy or ultrasound treatments.
Matt Jevon, Chief Executive of The British Association of Sports Trainers and visiting lecturer in Sports Rehabilitation at the University of Salford is very excited about this modality. "Laser therapy (LLLT) is our most commonly used electrotherapy apparatus, particularly in acute cases. We have used it in our support of over 300 players in the Student Rugby League World Cup with considerable success when compared against other electrotherapy and mechanical modalities."
LLLT is used as an adjunct to many of the manual therapies practised by our physiotherapists, all of whom appreciate the benefits of accuracy in application. We currently have two laser units and it will be first on our purchasing list after plinths as we expand into new clinics."
Example shown here is for a THOR LLLT system with 200mW laser probe and cluster probe.
Having thoroughly palpated and assessed the area, set the timer to 20 seconds
Set the Pulse frequency to one of the following settings:
2.5 Hz - for acute injuries;
5 KHz - for chronic injuries and non-healing or infected wounds.
Treat the top of the neck/occiput atlas for 20 seconds
Then treat the nerve exits at C7 / T1 for 20 seconds
Then treat the nerve root exit related to injury for 20 seconds, and continue to treat several points along the course of the nerve towards the injury at 20 second intervals.
Treat each tender point for 20 seconds with the THOR 200mW laser probe. Palpate for any changes (eg: reduction in pain, change in tissue texture, relaxation of muscle, etc). If there is no response, then treat the tender points again. Palpate for any changes and repeat once more if necessary.
Finally treat the surrounding soft tissue with the cluster probe for 2 mins per area
Times are approximate and can be varied according to the dept of the injury / build of the patient.
Be accurate during treatment, gapping and positioning joints appropriately to gain maximum exposure of the joint, treating 'around' tendons where possible and be as thorough as time permits. Use LLLT as soon as possible after injury, treating daily for acute conditions and less frequently as resolution occurs. Treat chronic inflammatory conditions twice weekly and osteo-arthritis weekly or fortnightly. Treat as many points as necessary during one session; do not move the probe during each application. Treat with single, then cluster probe during one session.
There are normally no adverse effects from LLLT , however, patients occasionally experience mild discomfort / ache after treatment. This is due to a restimulation of the inflammatory phase and should settle down after 24 - 48 hours.
Monday, September 19, 2007 6:21 PM Search the Web
What is LLLT? How does LLLT Work? What are the benefits of LLLT? Is LLLT different from Ultrasound? How do I use LLLT? What are the contra-indications of LLLT? Calculating LLLT Dosage Request more Information LLLT Research Abstracts
Calculating LLLT Dosage
There has been a lot of discussion about the best method to quantify LLLT dosage. However, it is my opinion that:
There is no agreed method of defining beam area
Dosage expressed as J/cm2 is inadequate
No agreed method for measuring LLLT dosage
So beam area is hard to define and there is no agreement in our industry for defining it. [I propose 1/e2 - will explain this soon].
Dosage expressed as J/cm2 is inadequate
“ Dosage” is usually calculated as Power / Beam Area x Time = J/cm2. However, to consider that dosage should equal J/cm2 is, in my opinion, inadequate.
Let me explain:
Assume there is a well-defined beam area and thus a quantifiable dosage.
A 500mW laser with a beam area of 0.25Cm2 used for 20 seconds delivers 40 J/cm2
A 200mW laser with a beam area of 0.1Cm2 used for 20 seconds delivers 40 J/cm2
A 30mW laser with a beam area of 0.015Cm2 used for 20 seconds also delivers 40 J/cm2
Each of these probes apparently apply the same "dosage". However, the total energy delivered is clearly different [10 Joules, 4 Joules and 0.6 Joules respectively].While dosage appears consistent using J/cm2, I suggest that the clinical results would be quite diverse. So I say that J/cm2 is an inadequate method of expressing dosage. Calculating the area of an laser beam should be simple:But laser beams are rarely round: Area of a circle = r2 Area of a circle = r1r2 And laser beams are rarely of uniform density:Some diode laser beams appear very distorted Where is the edge of the beam? What is the beam area?
Calculating the area of an laser beam should be simple: But laser beams are rarely round: Area of a circle = r 2 Area of a circle = r 1 r 2 And laser beams are rarely of uniform density: Some diode laser beams appear very distorted Where is the edge of the beam? What is the beam area?