Electromyography changes in assessment of functional status of muscles in subjects with knee-osteoarthritis undergoing low level laser therapy

The use of low level laser (light) therapy (LLLT) has recently expanded to cover areas of medicine that were not previously thought of as the usual applications such as wound healing and inflammatory orthopedic conditions. One of these novel application areas is LLLT for muscle fatigue and muscle injury. Since it is becoming agreed that mitochondria are the principal photoacceptors present inside cells, and it is known that muscle cells are exceptionally rich in mitochondria, this suggests that LLLT should be highly beneficial in muscle injuries. The ability of LLLT to stimulate stem cells and progenitor cells means that muscle satellite cells may respond well to LLLT and help muscle repair. Furthermore the ability of LLLT to reduce inflammation and lessen oxidative stress is also beneficial in cases of muscle fatigue and injury. This review covers the literature relating to LLLT and muscles in both preclinical animal experiments and human clinical studies. Athletes, people with injured muscles, and patients with Duchenne muscular dystrophy may all benefit.

Consensus Agreement on the Design and Conduct of Clinical Studies with Low-Level Laser Therapy and Light Therapy for Musculoskeletal Pain and Disorders

I am pleased to have the opportunity to serve as guest editor for this special issue of Lasers in Surgery and Medicine that concentrates on low level laser therapy (LLLT) also known as photobiomodulation. I would like to thank Drs. Stuart Nelson and Henry Chan for the invitation to be guest editor and to pay a special tribute to the talented and tireless Ms. Beth Mallen, without whom this would have been an impossible task. LLLT has been known since a few years after the discovery of lasers (incidentally celebrating their 50th anniversary this year). However, it is only in relatively recent times that LLLT has become scientifically and clinically accepted by even a fraction of the medical community. We hope this issue will make a contribution towards increasing the awareness among both physicians and the general scientific public that hard evidence is now available that “sheds light” on the basic mechanisms, pre-clinical applications and clinical benefits of LLLT. It contains a review, basic science and clinical research submissions providing new information concerning cell biology studies after LLLT and highlighting many possible clinical applications of LLLT.

Low level laser (light) therapy (LLLT) also known as photobiomodulation (PBM) therapy has been practiced for almost fifty years, and hundreds of positive clinical trials and thousands of laboratory studies have been published. Despite these impressive accomplishments LLLT has still not reached the stage of acceptance by mainstream medicine. The reasons for this were discussed at a recent Optical Society of America (OSA) Incubator meeting in Washington DC in 2014. Uncertainty about mechanisms was highlighted, and this paper will describe the current thinking. To drive LLLT towards mainstream medicine, we need better guidelines with standardized protocols and consistent parameters. Studies should be published in higher impact scientific and medical journals. Companies should avoid false promises and deceptive marketing, and physicians should receive a clearly defined return on investment with insurance reimbursement.

Acne vulgaris is a chronic inflammatory disease of the pilosebaceous unit with polymorphic manifestations. The four key elements leading to the formation of acne lesions are alteration of follicular keratinization that leads to comedones, increased and altered sebum production under androgen control, follicular colonization by  Propionibacterium acnes , and complex inflammatory mechanisms that involve both innate and acquired immunity. Phototherapy (light, lasers, and photodynamic therapy) has been proposed as an alternative therapeutic modality to treat acne vulgaris and is proposed to have less side effects compared to other treatment options. Recently, low-level laser (light) therapy (LLLT) which refers to the use of red-beam or near-infrared laser with a wave-length between 600 and 1000 nanometers and power from 5 to 500 milliwatts, starts to be used in the treatment of acne. Mechanism of action of LLLT for acne is through photochemical reaction that produces reactive free radicals and singlet oxygen species which in turn lead to bacterial destruction by blue light. Meanwhile, red light can affect the sebum secretion of sebaceous glands, change keratinocytes behavior, and modulate cytokines from macrophages and other cells that reduce inflammation. LLLT is proposed to be effective as an alternative modality for inflammatory type lesions in acne vulgaris.   Keywords : acne vulgaris, blue light, low level laser therapy, red light. Normal 0 false false false EN-US X-NONE X-NONE

Pre-conditioning by ischemia, hyperthermia, hypothermia, hyperbaric oxygen (and numerous other modalities) is a rapidly growing area of investigation that is used in pathological conditions where tissue damage may be expected. The damage caused by surgery, heart attack, or stroke can be mitigated by pre-treating the local or distant tissue with low levels of a stress-inducing stimulus, that can induce a protective response against subsequent major damage. Low-level laser (light) therapy (LLLT) has been used for nearly 50 years to enhance tissue healing and to relieve pain, inflammation and swelling. The photons are absorbed in cytochrome(c) oxidase (unit four in the mitochondrial respiratory chain), and this enzyme activation increases electron transport, respiration, oxygen consumption and ATP production. A complex signaling cascade is initiated leading to activation of transcription factors and up- and down-regulation of numerous genes. Recently it has become apparent that LLLT can also be effective if delivered to normal cells or tissue before the actual insult or trauma, in a pre-conditioning mode. Muscles are protected, nerves feel less pain, and LLLT can protect against a subsequent heart attack. These examples point the way to wider use of LLLT as a pre-conditioning modality to prevent pain and increase healing after surgical/medical procedures and possibly to increase athletic performance.

Excitotoxicity describes a pathogenic process whereby death of neurons releases large amounts of the excitatory neurotransmitter glutamate, which then proceeds to activate a set of glutamatergic receptors on neighboring neurons (glutamate, N-methyl-D-aspartate (NMDA), and kainate), opening ion channels leading to an influx of calcium ions producing mitochondrial dysfunction and cell death. Excitotoxicity contributes to brain damage after stroke, traumatic brain injury, and neurodegenerative diseases, and is also involved in spinal cord injury. We tested whether low level laser (light) therapy (LLLT) at 810 nm could protect primary murine cultured cortical neurons against excitotoxicity in vitro produced by addition of glutamate, NMDA or kainate. Although the prevention of cell death was modest but significant, LLLT (3 J/cm(2) delivered at 25 mW/cm(2) over 2 min) gave highly significant benefits in increasing ATP, raising mitochondrial membrane potential, reducing intracellular calcium concentrations, reducing oxidative stress and reducing nitric oxide. The action of LLLT in abrogating excitotoxicity may play a role in explaining its beneficial effects in diverse central nervous system pathologies.

We review the use of transcranial low-level laser (light) therapy (LLLT) as a possible treatment for traumatic-brain injury (TBI). The basic mechanisms of LLLT at the cellular and molecular level and its effects on the brain are outlined. Many interacting processes may contribute to the beneficial effects in TBI including neuroprotection, reduction of inflammation and stimulation of neurogenesis. Animal studies and clinical trials of transcranial-LLLT for ischemic stroke are summarized. Several laboratories have shown that LLLT is effective in increasing neurological performance and memory and learning in mouse models of TBI. There have been case report papers that show beneficial effects of transcranial-LLLT in a total of three patients with chronic TBI. Our laboratory has conducted three studies on LLLT and TBI in mice. One looked at pulsed-vs-continuous wave laser-irradiation and found 10 Hz to be superior. The second looked at four different laser-wavelengths (660, 730, 810, and 980 nm); only 660 and 810 nm were effective. The last looked at different treatment repetition regimens (1, 3 and 14-daily laser-treatments).

To determine the in vitro activity of the low-level laser (light) therapy (LLLT) device (Phovia; Vetoquinol) on Malassezia pachydermatis. Clinical isolates of M pachydermatis (n = 30) and a commercially available anamorph of M pachydermatis (ATCC strain 14522) were used in this study. Both groups of organisms were plated on potato agar plates and exposed to the LLLT device for 2, 4, 6, and 8 minutes with a 30-second break after every 2 minutes of exposure. The plates were then incubated at 37 °C for 48 hours. Each experiment was run in duplicate. The experiment for the internal control was repeated independently 6 times. Nonirradiated plates served as the viability control (positive control). The number of CFUs between each treatment and the control was analyzed using a repeated-measures ANOVA or a Friedman test followed by a post hoc analysis. Compared to the control, there was a statistically significant decline in CFUs after a minimum of 4 minutes of exposure to the LLLT device in both groups compared to unexposed controls. This preliminary in vitro study demonstrated that the LLLT device tested can inhibit the growth of M pachydermatis. This in vitro study offers a novel proof-of-concept approach to treating Malassezia infections in veterinary medicine. Low-level laser (light) therapy has the potential to shorten treatment durations and reduce side effects, making it a promising alternative to standard antifungal therapy, particularly in the context of antifungal resistance.

Recently, low-level laser (light) therapy has been used to increase muscle performance in intense exercises. However, there is a lack of understanding of the time response of muscles to light therapy. The first purpose of this study was to determine the time response for light-emitting diode therapy (LEDT)-mediated increase in adenosine triphosphate (ATP) in the soleus and gastrocnemius muscles in mice. Second purpose was to test whether LEDT can increase the resistance of muscles to fatigue during intense exercise. Fifty male Balb/c mice were randomly allocated into two equal groups: LEDT-ATP and LEDT-fatigue. Both groups were subdivided into five equal subgroups: LEDT-sham, LEDT-5 min, LEDT-3 h, LEDT-6 h, and LEDT-24 h. Each subgroup was analyzed for muscle ATP content or fatigue at specified time after LEDT. The fatigue test was performed by mice repeatedly climbing an inclined ladder bearing a load of 150 % of body weight until exhaustion. LEDT used a cluster of LEDs with 20 red (630 ± 10 nm, 25 mW) and 20 infrared (850 ± 20 nm, 50 mW) delivering 80 mW/cm(2) for 90 s (7.2 J/cm(2)) applied to legs, gluteus, and lower back muscles. LEDT-6 h was the subgroup with the highest ATP content in soleus and gastrocnemius compared to all subgroups (P < 0.001). In addition, mice in LEDT-6 h group performed more repetitions in the fatigue test (P < 0.001) compared to all subgroups: LEDT-sham and LEDT-5 min (~600 %), LEDT-3 h (~200 %), and LEDT-24 h (~300 %). A high correlation between the fatigue test repetitions and the ATP content in soleus (r = 0.84) and gastrocnemius (r = 0.94) muscles was observed. LEDT increased ATP content in muscles and fatigue resistance in mice with a peak at 6 h. Although the time response in mice and humans is not the same, athletes might consider applying LEDT at 6 h before competition.

To evaluate the efficiency of therapeutic Ultrasound, low level laser and compression therapy for healing of venous Leg ulcers and Compare the effect of modalities on the ulcers. Three groups were included in the study. Group I: 20 patients with leg ulcers treated with low level laser therapy. Group II: 20 patients with leg ulcers treated with ultrasound therapy. Group III: 20 patients with leg ulcers treated by compression therapy (four layer bandage) were used in this study. All patients were subjected to detailed history, clinical evaluation in addition to X-ray of legs and feet, and Doppler ultrasound of both legs. The main variables for follow up were the measurement of the area of the lesions under aseptic conditions at 0, 1, 2, 3 months and qualitative clinical evaluation of the ulcers by physician and by the patient. The results from group I, group II and group III were obtained and then compared with each others. According to the size of the ulcer, some ulcers heal within 1 month which is (15.6%) in group I, (10%) in group II, and (28.5%) in group III. Some ulcers heal within 2 months which is (28%) in group I, (23.3%) in group II and (37%) in group III. The remaining ulcers heal within 3 months or more which are (56%) in group I, (66.6%) in group II and (34.2%) in group III. Thus the percentage of healing denoting that compression bandage technique used in group III is the most efficient in healing of chronic venous leg ulcer followed by laser therapy and lastly US therapy (P = 0.04 at the end of the first month and P = 0.03 at the end of the third month). Compression therapy is the most efficient treatment of venous leg ulcers. Low level laser therapy and Ultrasound therapy are useful methods as a conservative treatment of venous leg ulcers and can be used in ulcers of small size.

Low-level laser (light) therapy (LLLT) involves absorption of photons being in the mitochondria of cells leading to improvement in electron transport, increased mitochondrial membrane potential (MMP), and greater ATP production. Low levels of reactive oxygen species (ROS) are produced by LLLT in normal cells that are beneficial. We exposed primary cultured murine cortical neurons to oxidative stressors: hydrogen peroxide, cobalt chloride and rotenone in the presence or absence of LLLT (3 J/cm², CW, 810 nm wavelength laser, 20 mW/cm²). Cell viability was determined by Prestoblue™ assay. ROS in mitochondria was detected using Mito-sox, while ROS in cytoplasm was detected with CellRox™. MMP was measured with tetramethylrhodamine. In normal neurons LLLT elevated MMP and increased ROS. In oxidatively-stressed cells LLLT increased MMP but reduced high ROS levels and protected cultured cortical neurons from death. Although LLLT increases ROS in normal neurons, it reduces ROS in oxidatively-stressed neurons. In both cases MMP is increased. These data may explain how LLLT can reduce clinical oxidative stress in various lesions while increasing ROS in cells in vitro.

Background: Recurrent aphthous stomatitis (RAS) are the most common oral ulceration in lesions of the oral mucosa. Treatment aims to reduce pain and healing time. Low-level Diode laser therapy can relieve pain, anti-inflammatory, reduce edema, stimulate cell biology, and stimulate healing. Low-level Diode laser therapy is an alternative therapy to conventional drug use, promising to help improve the quality of life, improve the patient's quality of life and avoid complications caused by long-term drug use. Objectives: To evaluate the therapeutic effect of a low-level Diode laser on RAS treatment to reduce pain, size of ulcers, and healing time. Materials and methods: A clinical study was conducted on 30 patients who presented RAS lesions were treated with low-level laser therapy. The patients were evaluated for the size, position, pain score, form of ulcers, healing time before and immediately, fourth and sixth day after treatment. The data was analyzed using SPSS 20. Results: The VAS score pre-treatment was 4.33±1.65, immediately post-treatment was 1.20±1.06. The size of ulcers pre-treatment was 4.58±2.35mm, and post-treatment fourth day was 2.47±2.30mm. The healing time was 5.04±0.32 days. Conclusion: Low-level Diode laser therapy is effective in RAS treatment to reduce pain, size of ulcers, and healing time.

The purpose of this study was to investigate whether low-level laser (light) therapy (LLLT) can provide fatigue resistance via maximum repetitions (RM) with an isokinetic dynamometer, and decrease electromyography fatigue index (EFI). LLLT has been used to increase muscle performance when applied before or after intense exercises. This study was a randomized, double-blind, crossover trial with placebo. Seven young men (21±3 years of age) who were clinically healthy, were allocated into two groups: active laser (LLLT) and placebo laser (Placebo). Both groups were assessed at baseline, at one training session, and at the end of this study. Baseline and final assessments recorded the number of RM of knee flexion-extensions using an isokinetic dynamometer at 60 degrees/sec in conjunction with EFI recorded by median frequency. The training sessions consisted of three sets of 20 RM of knee flexion-extensions using an isokinetic dynamometer at 60 degrees/sec plus LLLT (808 nm, 100 mW, 4 J), or placebo, applied to quadriceps femoris muscles between sets, and after the last series of this exercise. After 1 week (washout period), all volunteers were exchanged among groups and then all assessments were repeated. LLLT group increased RM (52%; p=0.002) with a small EFI for the vastus medialis (p=0.004) and rectus femoris (p=0.004). These results suggest an increased muscle fatigue resistance when LLLT is applied during rest intervals, and after the last series of intense exercises.

The symptoms of knee osteoarthritis (KOA) severely affect the life quality of the elderly population. Low-level laser therapy, heat therapy, and massage therapy are widely used as independent treatments for joint disorders. However, there are very limited reports of a combination of these therapies into an integrated device for KOA so far. This study aims to develop a novel hybrid therapeutic device that can meet various requirements for knee therapy. Our hybrid therapeutic device (CUHK-OA-M2) integrated with low-level laser therapy, heat therapy, and local massage therapy can effectively provide patients with KOA with relief from their clinical symptoms. A pilot test of 50 community-dwelling elderly volunteers with KOA was performed. Finally, 43 volunteers completed two treatment periods (30 days each) and two post-treatment periods (30 days each). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were collected and analyzed after each period. The outputs of the low-level laser, heating, and massage therapies significantly decreased the WOMAC scores in terms of pain, stiffness, function and total WOMAC after two treatment periods (p < 0.05). Although the score increased slightly after the post-treatment period, it was still lower than the baseline, indicating the treatment outcome could last for an extended period. Therefore, our CUHK-OA-M2 device, as an integrated multi-functional hybrid therapeutic device, is therapeutically significant for treating osteoarthritis symptoms on the knee joints of elderly subjects.