Placebo Low-level Laser Therapy Research Articles

Effects of low-level laser therapy on burning pain and quality of life in patients with burning mouth syndrome: a systematic review and meta-analysis

BackgroundBurning mouth syndrome (BMS) is a complex chronic pain disorder that significantly impairs patients' quality of life. Low-level laser therapy (LLLT) uses infrared or near-infrared light to produce analgesic, anti-inflammatory, and biological stimulation effects. The aim of this systematic review is to evaluate the effect of LLLT on burning pain, quality of life, and negative emotions in patients with BMS.MethodsThe PubMed, Embase, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Cochrane Library, Web of Science, and Scopus databases were searched up January 2023 to identify relevant articles. All randomized controlled trials that were published in English and examined the use of LLLT treatment for BMS were included. The methodological quality of the included trials was assessed using the Cochrane risk of bias tool for randomized controlled trials (RCTs). A meta-analysis was performed to evaluate burning pain, quality of life, and negative emotions. Sensitivity, subgroup, and funnel plot analyses were also carried out.ResultsFourteen RCTs involving a total of 550 patients with BMS met the inclusion criteria. The results showed that LLLT (measured by the Visual Analog Scale; SMD: -0.87, 95% CI: -1.29 to -0.45, P < 0.001) was more effective for reducing burning pain than placebo LLLT or clonazepam. LLLT improved quality of life (evaluated by the Oral Health Impact Profile-14; SMD: 0.01, 95% CI: -0.58 to 0.60, P = 0.97) and negative emotions (evaluated by the Hospital Anxiety and Depression Scale; SMD: -0.12, 95% CI: -0.54 to 0.30, P = 0.59), but these effects were not statistically significant.ConclusionsThe meta-analysis revealed that LLLT may be an effective therapy for improving burning pain in patients with BMS, and producing a positive influence on quality of life and negative emotions. A long-term course of intervention, a larger sample size, and a multidisciplinary intervention design are urgently needed in future research.Trial registrationPROSPERO registration number: CRD42022308770.

CAN COMBINING LOW LEVEL LASER THERAPY WITH COMPUTER GUIDED FLAPLESS PIEZOSURGICAL OSTEOTOMY ACHIEVE A PAINLESS IMPLANT SURGERY? FINDINGS OF SPLIT MOUTH RANDOMIZED CONTROLLED TRIAL.

Developing a safe and accurate surgical technique that offers higher patient satisfaction will be a great improvement in the field of oral implantology. This study was to investigate the effect of Low-Level Laser Therapy (LLLT) on pain and swelling after flapless computer guided implant site preparation utilizing a novel surgical guide designed to be used with piezotome. A total of thirty patients were enrolled in this study having history of bilateral extractions in the lower molar area not less than 6 months ago. One side from each patient was randomly selected for the intervention group to receive LLLT immediately after insertion of bendable one-piece implant (Rough-B Implant, Monoimplant, Novodent SA, Swizerland) using diode laser with a wavelength of 980 nm and a 100 mW energy for 1 minute. The other side received placebo LLLT and was regarded as a control group. Piezo-surgical implant site preparation was done on both sides using a third generation piezotome (Surgic Touch, Guilin Woodpecker Medical Instrument Co., Ltd, China). Pain and swelling scores were measured by utilizing a Visual Analogue Scale (VAS) and a graded swelling scale respectively. The measurements were recorded on both sides after 2, 6 and 24 hour of the day of surgery then at 2, 3, 4 and 7 days post-surgically. In general, the overall scores were ranging from very mild to mild degree of pain and swelling. Females reported significantly higher pain score than males with a mean score of 20.3 ± 5.1 for females and 14.7 ± 3.1 for males (P < .05). Swelling showed no statistically significant results between females and males (P> .05). Pain scores were found to be significantly lower in the LLLT side after 2, 6, 24, 48 hour of implant insertion (P < .05). Moreover, Sweling scores were also found to be significantly lower in the LLLT side after 2, 6, 24, 48 hour, and at day 3 of implant insertion (P < .05). However, day 4 and day 7 showed very minimal if any pain and swelling with insignificant differences between the 2 sides (P > .05). LLLT was found to be an effective non pharmacological method for relieving pain after implant insertion. Piezosurgical flapless implant placement combined with LLLT is considered an effective, tolerable and minimally invasive procedure (ClinicalTrials.gov NCT01857804).

Short- and Long-Term Effectiveness of Low-Level Laser Therapy Combined with Strength Training in Knee Osteoarthritis: A Randomized Placebo-Controlled Trial.

Background: Both physical activity and low-level laser therapy (LLLT) can reduce knee osteoarthritis (KOA) inflammation. We conducted a randomized clinical trial to investigate the short- and long-term effectiveness of LLLT combined with strength training in persons with KOA. Methods: Fifty participants were randomly divided in two groups, one with LLLT plus strength training (n = 26) and one with placebo LLLT plus strength training (n = 24). LLLT and strength training were performed triweekly for 3 and 8 weeks, respectively. In the laser group, 3 joules 904 nm wavelength laser was applied to fifteen points (45 joules) per knee per session. Patient-reported outcomes, physical tests, and ultrasonography assessments were performed at baseline and 3, 8, 26, and 52 weeks after initial LLLT or placebo therapy. The primary outcomes were pain on movement, at rest, at night (Visual Analogue Scale), and globally (Knee injury and Osteoarthritis Outcome Score (KOOS) subscale). Parametric data were assessed with analysis of variance using Šidák’s correction. Results: There were no significant between-group differences in the primary outcomes. However, in the laser group there was a significantly reduced number of participants using analgesic and non-steroidal anti-inflammatory drugs and increased performance in the sit-to-stand test versus placebo-control at week 52. The joint line pain pressure threshold (PPT) improved more in the placebo group than in the laser group, but only significantly at week 8. No other significant treatment effects were present. However, pain on movement and joint line PPT were worse in the placebo group at baseline, and therefore, it had more room for improvement. The short-term percentage of improvement in the placebo group was much higher than in similar trials. Conclusions: Pain was reduced substantially in both groups. LLLT seemed to provide a positive add-on effect in the follow-up period in terms of reduced pain medication usage and increased performance in the sit-to-stand test.

Effects of moderate aerobic exercise, low-level laser therapy, or their combination on muscles pathology, oxidative stress and irisin levels in the mdx mouse model of Duchenne muscular dystrophy.

This study aimed to investigate how the combined use of low-level laser therapy (LLLT) and exercise, to reduce the possible side effects and/or increase the benefits of exercise, would affect oxidative stress, utrophin, irisin peptide, and skeletal, diaphragmatic, and cardiac muscle pathologies. In our study, 20 mdx mice were divided into four groups. Groups; sedentary and placebo LLLT (SC), sedentary and LLLT (SL), 30-min swimming exercise (Ex), and 30-min swimming exercise and LLLT (ExL). After 8weeks of swimming exercise, muscle tests, biochemically; oxidative stress index (OSI), utrophin and irisin levels were measured. Skeletal, diaphragmatic and cardiac muscle histopathological scores, skeletal and cardiac muscle myocyte diameters were determined under the light and electron microscope. While only irisin levels were increased in group SL compared to SC, it was determined that OSI, heart muscle histopathological scores decreased and irisin levels increased in both exercise groups (p < 0.05). In addition, in the ExL group, an increase in rotarod and utrophin levels, and a decrease in muscle and diaphragm muscle histopathological scores were observed (p < 0.05). It was determined that the application of swimming exercise in the mdx mouse model increased the irisin level in the skeletal muscle, while reducing the OSI, degeneration in the heart muscle, inflammation and cardiopathy. When LLLT was applied in addition to exercise, muscle strength, skeletal muscle utrophin levels increased, and skeletal and diaphragmatic muscle degeneration and inflammation decreased. In addition, it was determined that only LLLT application increased the level of skeletal muscle irisin.

Effect of Low-Level Laser Therapy on Bacterial Counts of Contaminated Traumatic Wounds in Dogs.

Introduction: The clinical effect of low-level laser therapy (LLLT) on canine wounds is still under debate. The aim of this pilot study was to evaluate the potential influence of LLLT on the bacterial loads of wounds, using two different energy densities or doses of laser light as an adjuvant therapy for traumatic contaminated wound management. Methods: A prospective, randomized, blinded, placebo-controlled pilot clinical trial was used to evaluate the effect of two different doses of LLLT as an adjuvant treatment of contaminated traumatic wounds on the bacterial load and wound scoring in dogs. Fourteen dogs with traumatic bites or laceration wounds were randomly assigned to one of the three groups. Animals in groups A and B received a dose of LLLT of 6 and 2 J/cm2 respectively. Four wavelengths were used simultaneously: 660 nm, 800 nm, 905 nm, and 970 nm. Animals in group C received placebo LLLT. Bacterial burden and clinical wound scores were evaluated. Results: A statistically significant reduction in the average count of colony forming units was observed in group B (2 J/cm2) when compared to placebo group C. Group B also showed improved wound scores. No clinically adverse effects were observed in the patients treated with LLLT. Conclusion: LLLT, with the parameters used in this pilot trial, decreased bacterial loads of contaminated wounds in dogs and improved wound scores, especially when using a dose of 2 J/ cm2. This is the first time the effect of LLLT on bacterial load has been investigated in a clinical setting using traumatic wounds in canine patients.

Dose-response and efficacy of low-level laser therapy on diabetic foot ulcers healing: Protocol of a randomized controlled trial

BackgroundCurrent evidence shows that low-level laser therapy (LLLT) is an effective non-invasive and non-pharmacological strategy to treat diabetic foot ulcers (DFU). However, knowledge of parameterization efficacy remains unclear. Methods: This randomized, double-blind, controlled trial will be conducted at the Physical Therapy University Clinic. Eighty volunteers will be randomized into four groups. The control group will receive placebo LLLT + conventional treatment. The three active groups will receive 10 (G10), 8 (G8), or 4 J/cm2 (G4) of GaAs 904 nm LLLT plus conventional treatment twice a week for 20 sessions. Conventional treatment involves cleaning and dressing the ulcers. The main outcome will be the area of ulcers and Wagner classification score. Assessments will take place before treatment, after 5 and 10 weeks of treatment, and in the third month after treatment, by a blinded evaluator. Implications: This trial can potentially provide important information and assist in clinical decision-making regarding DFU treatment with LLLT.Trial Registration:NCT04246814, registered 29th January 2020.

Therapeutic and photobiomodulation effects of low-level laser irradiation on Egyptian patients with carpal tunnel syndrome: a placebo-controlled study

Background/Aim Carpal tunnel syndrome (CTS) is the most prevalent mononeuropathy, where the median nerve is entrapped in the hand; it affects women more than men and is diagnosed by clinical and electrophysiological examination. Low-level laser therapy (LLLT) was suggested for conservative treatment of CTS. The aim of this study was to evaluate the role of LLLT in the treatment of CTS. Patients and methods The study was carried out on 40 female patients with CTS. Patients were recruited from Neurology and Rheumatology clinics at National Research Centre, Egypt. The patients were randomly divided into two groups (20 patients each). The first group was subjected to active LLLT, and the second group was subjected to placebo (sham) LLLT. The patients of the first group were treated with real LLLT by gallium-aluminum-arsenide laser (905 nm) with touch sensor guide light +8 diodes of power output of 100 MW each (800 MW total), and pulsed mode of frequency of 10 000 Hz over two areas, one extends from the proximal palmer crease to the distal wrist crease and the other over the thenar area, for three times per week for 4 weeks (12 sessions). All patients were subjected to clinical and nerve conduction studies evaluations. Results LLLT showed significant reduction in erythrocyte sedimentation rate and visual analog scale and significant improvement in functional status scale and symptom severity scale (P Conclusion This study confirmed the safety and positive effects of LLLT on pain, inflammation, functional capacity, and electro-neurophysiological aspects of median nerve in patients with CTS.

Can the severity of orofacial myofunctional conditions interfere with the response of analgesia promoted by active or placebo low-level laser therapy?

ABSTRACT Objective To analyze the influence of orofacial myofunctional condition (OMC) on pain perception, temporomandibular disorders (TMD) severity, and the response to low-level laser therapy (LLLT) in women with painful TMD. Methods Seventy-eight women, 59 with TMD, received active laser (30) or placebo (29), with 19 controls. OMC, TMD severity, pain intensity, and pressure pain threshold (PPT) were assessed at different times during the masticatory test: before treatment (LLLT dose: 780nm), during, and after 30 days. Results No correlation was found between OMC and pain perception or TMD severity (p > 0.05). The active and placebo LLLT showed reduction of pain during chewing and better recovery levels during the rest period (p > 0.05), without differences between OMC groups. Discussion The perception of pain and severity of TMD are not correlated with the OMC, and the response of analgesia promoted by active LLLT or placebo is not associated with OMC.

Acute Effects of Low-Level Laser Therapy on Patients' Functional Capacity in the Postoperative Period of Coronary Artery Bypass Graft Surgery: A Randomized, Crossover, Placebo-Controlled Trial.

The aim of this study was to evaluate the acute effects of low-level laser therapy (LLLT) on the functional capacity to exercise tested by incremental shuttle walking test (ISWT) after coronary artery bypass graft (CABG) surgery. Fifteen male patients (60 ± 9 years) were crossed over during the experiment, to compare the outcomes after active LLLT and placebo LLLT treatments. LLLT (850 nm, 200 mW, 30 J to each point, resulting in a total of 240 J per quadriceps muscle), using a multidiode cluster (five spots; 6 J/spot) in eight points per leg was performed 3 min before the ISWT. We analyzed distance walked, Borg scale of perceived exertion, heart rate, and brachial arterial blood pressure. Markers of tissue damage [lactate dehydrogenase (LDH)] and oxidative stress [lipid peroxidation, total thiol levels, and antioxidant enzyme activity of superoxide dismutase (SOD) and catalase (CAT)] were also measured in peripheral blood. Comparison of the distances walked revealed no significant differences between the LLLT and placebo LLLT groups (p = 0.779). Regarding the Borg scale (p = 0.567), heart rate (p = 0.506) as well as systolic and diastolic blood pressure (p = 0.164 and p = 0.140, respectively), no differences were observed between LLLT and placebo LLLT groups. Application of LLLT was not able to change levels of LDH (p = 0.214), oxidative lipid damage (p = 0.733), total thiol levels (p = 0.925), SOD (p = 0.202), and CAT (p = 0.825) enzyme activities. Acute LLLT improved neither functional capacity to exercise nor the markers of oxidation after CABG. Registered as a clinical trial (NCT02688426).

Non-specific effects and clusters of women with painful TMD responders and non-responders to LLLT: double-blind randomized clinical trial.

The aim was to analyze the non-specific effects (placebo, spontaneous remission, and regression to the mean) of the low-level laser therapy (LLLT) in women with myofascial pain (painful temporomandibular disorder (TMD)), as well as to differentiate between responders and non-responder clusters to active and placebo LLLT according to the anxiety levels, salivary cortisol, use of oral contraceptives, and premenstrual period. Sixty-four women diagnosed with myofascial pain (Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD)) were included, divided into laser (n = 20), placebo group (n = 21), and 23 controls (without treatment (WT)). The LLLT applied was 780nm, masseter and temporal = 5J/cm2 (20mW-0.5W/cm2), and TMJ area = 7.5J/cm2 (30mW-0.8W/cm2), eight sessions, twice a week. The pain intensity (visual analogue scale (VAS)), anxiety (Beck Anxiety Inventory), salivary cortisol, and menstrual cycle's data at the baseline, T1-T8, and 30days after LLLT (follow-up) were evaluated. The laser group showed 80% of pain reduction, placebo 85%, and WT 43% in T8. Women with severe anxiety and at the premenstrual period did not reduce pain with any LLLT. Active and placebo LLLT had similar effectiveness during the treatment period; however, women with moderate anxiety, cortisol levels above 10ng/ml, and without contraceptive use maintain analgesia longer with active LLLT than placebo (follow-up 30days). Women with low levels of anxiety, salivary cortisol below 10ng/ml, and with contraceptive use showed the higher pain reduction. The analgesia promoted by LLLT in women with myofascial pain is a result of non-specific effects during the treatment period, although active LLLT is more effective in maintaining the analgesia after treatment (30days) for the cluster of women with moderate anxiety, salivary cortisol above 10ng/ml, and without contraceptive use.

Muscle fiber conduction velocity and EMG amplitude of the upper trapezius muscle in healthy subjects after low-level laser irradiation: a randomized, double-blind, placebo-controlled, crossover study.

Although low-level laser therapy (LLLT) is an important resource for the treatment of non-specific neck pain patients, the dose which presents the greatest therapeutic potential for the treatment of this pathology is still unclear. The present study aimed to evaluate the immediate effect of LLLT on the muscle fiber conduction velocity (MFCV) and electromyographic activity (EMG) of the upper trapezius (UT) muscle in healthy individuals. A total of 20 healthy subjects were enrolled in a randomized, double-blind, crossover study. Active LLLT (820nm wavelength, 30mW, energy total 18J) or placebo LLLT (pLLLT) was delivered on the UT muscle. Each subject was subjected to a single session of active LLLT and pLLLT. Surface electromyography (sEMG) signal of the UT muscle was recorded during five different step contractions of shoulder elevation force (10-30% maximal voluntary contraction) pre- and post-LLLT irradiation. The values of MFCV and sEMG global amplitude (RMSG) were used to calculate the effects of LLLT. The results showed no difference in the MFCV comparing the LLLT and pLLLT groups (F = 0.72 p = 0.39, η p2 = 0.004). However, a significant difference was observed in the RMSG between the LLLT and pLLLT (F 1,2 = 16.66; P < 0.0001, η p2 = 0.09). Individuals who received active LLLT presented a significant decrease in RMSG after laser application (F = 61.28; p < 0.0001, η p2 = 0.43). In conclusion, the 820nm LLLT, with energy total of 18J, did not alter the MFCV but significantly reduced the sEMG signal amplitude of the upper trapezius muscle in healthy subjects to a level of up to 30% of maximal voluntary contraction.

Long-term results of a randomized, controlled, double-blind study of low-level laser therapy before exercises in knee osteoarthritis: laser and exercises in knee osteoarthritis

Objectives: To assess the long-term effects of low-level laser therapy (LLLT), in combination with strengthening exercises in patients with osteoarthritis of the knee. Design: Follow-up results at three and six months in a previously published randomized, double-blind, placebo-controlled trial. Setting: Specialist Rehabilitation Services. Subjects: Forty participants of both genders, aged 50–75 years with knee osteoarthritis grade 2–4 on Kellgren–Lawrence scale. Intervention: The LLLT group received 10 LLLT treatments with invisible infrared laser (904 nm, 3 Joules/point) over three weeks followed by an eight-week supervised strengthening exercise program. The placebo LLLT group received identical treatment, but the infrared laser output was disabled. Main measures: Pain on a visual analogue scale, paracetamol consumption, and osteoarthritis severity measured by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Lequesne Index. Results: The new data obtained during the follow-up period showed that all outcomes remained stable and there were no significant differences between the groups at three and six months. However, daily consumption of rescue analgesics (paracetamol) was significantly lower in the LLLT group throughout the follow-up period, ending at a group difference of 0.45 vs. 3.40 units (P < 0.001) at six months follow-up. We conclude that within the limitations of this small study, the previously reported improvement after LLLT plus exercise was maintained for a period of six months. Conclusion: We find that the immediate post-intervention improvements from LLLT plus strengthening exercises were maintained for six months.

Low level laser therapy associated with a strength training program on muscle performance in elderly women: a randomized double blind control study.

The aging process leads to a gradual loss of muscle mass and muscle performance, leading to a higher functional dependence. Within this context, many studies have demonstrated the benefits of a combination of physical exercise and low level laser therapy (LLLT) as an intervention that enhances muscle performance in young people and athletes. The aim of this study was to evaluate the effects of combination of LLLT and strength training on muscle performance in elderly women. For this, a hundred elderly women were screened, and 48 met all inclusion criteria to participate in this double-blind placebo-controlled trial. Volunteers were divided in three groups: control (CG = 15), strength training associated with placebo LLLT (TG = 17), and strength training associated with active LLLT (808nm, 100mW, 7J) (TLG = 16). The strength training consisted of knee flexion-extension performed with 80% of 1-repetition maximum (1-RM) during 8weeks. Several outcomes related to muscle performance were analyzed through the 6-min walk test (6-MWT), isokinetic dynamometry, surface electromyography (SEMG), lactate concentration, and 1-RM. The results revealed that a higher work (p = 0.0162), peak torque (p = 0.0309), and power (p = 0.0223) were observed in TLG compared to CG. Furthermore, both trained groups increased the 1-RM load (TG vs CG: p = 0.0067 and TLG vs CG: p < 0.0001) and decreased the lactate concentration in the third minute after isokinetic protocol (CG vs TLG: p = 0.0289 and CG vs TG: p = 0.0085). No difference in 6-MWT and in fatigue levels were observed among the groups. The present findings suggested that LLLT in combination with strength training was able to improve muscle performance in elderly people.

Acute effects of low-level laser therapy irradiation on blood lactate and muscle fatigue perception in hospitalized patients with heart failure-a pilot study.

The objective of the present study is to evaluate the acute effects of low-level laser therapy (LLLT) on functional capacity, perceived exertion, and blood lactate in hospitalized patients with heart failure (HF). Patients diagnosed with systolic HF (left ventricular ejection fraction <45%) were randomized and allocated prospectively into two groups: placebo LLLT group (n = 10)-subjects who were submitted to placebo laser and active LLLT group (n = 10)-subjects who were submitted to active laser. The 6-min walk test (6MWT) was performed, and blood lactate was determined at rest (before LLLT application and 6MWT), immediately after the exercise test (time 0) and recovery (3, 6, and 30min). A multi-diode LLLT cluster probe (DMC, São Carlos, Brazil) was used. Both groups increased 6MWT distance after active or placebo LLLT application compared to baseline values (p = 0.03 and p = 0.01, respectively); however, no difference was observed during intergroup comparison. The active LLLT group showed a significant reduction in the perceived exertion Borg (PEB) scale compared to the placebo LLLT group (p = 0.006). In addition, the group that received active LLLT showed no statistically significant difference for the blood lactate level through the times analyzed. The placebo LLLT group demonstrated a significant increase in blood lactate between the rest and recovery phase (p < 0.05). Acute effects of LLLT irradiation on skeletal musculature were not able to improve the functional capacity of hospitalized patients with HF, although it may favorably modulate blood lactate metabolism and reduce perceived muscle fatigue.

Effects of low-level laser therapy on performance, inflammatory markers, and muscle damage in young water polo athletes: a double-blind, randomized, placebo-controlled study.

This study aimed to evaluate the effects of 5 days of 810-nm low-level laser therapy (LLLT) intervention on inflammatory and muscle damage markers and performance in young water polo players. Twenty young male water polo players participated in the study, which was designed as a randomized, double-blinded, placebo-controlled trial. Active LLLT or an identical placebo LLLT were delivered to eight points on the adductor muscle region immediately after each training day. Performance was measured by a 200-m maximal swimming (P200) and a 30-s crossbar jump test (30CJ) which was performed every day before training, and blood samples were drawn pre and post the final LLLT intervention to measure interleukins (IL) and muscle damage markers. There was no significant change in the P200 exercise in the LLLT group compared with the placebo group but there was a moderate improvement in the 30CJ (8.7 ± 2.6 %). IL-1β and tumor necrosis factor-alpha presented increased (P < 0.016) concentration within group 48 h after the last LLLT intervention compared to pre, 0, and 24 h, but did not differ between groups. IL-10 increased over time in the placebo group and reached a moderate effect compared to the LLLT group. The creatine kinase decreased significantly (P = 0.049) over the time within the LLLT treatment group, but there was no significant change in lactate dehydrogenase (P = 0.150). In conclusion, LLLT resulted in a non-significant, but small to moderate effect on inflammatory and muscle damage markers and a moderate effect on performance in water polo players. In addition, the lack of positive results could be due to the small area covered by irradiation and this should be considered in future studies.

LLLT for the management of patients with ankylosing spondylitis.

This study aimed to compare the effectiveness of the combined low-level laser therapy (LLLT) and passive stretching with combined placebo LLLT laser and the same passive stretching exercises in patients suffering from Αnkylosing spondylitis. Forty-eight patients suffering from Αnkylosing spondylitis participated in the study and were randomized into two groups. Group A (n = 24) was treated with a λ = 820 Ga-Al-As laser CW, with power intensity = 60 mW/cm(2), energy per point in each session = 4.5 J, total energy per session = 27.0 J, in contact with specific points technique, plus passive stretching exercises. Group B (n = 24), received placebo laser plus the same passive stretching exercises. Both groups received 12 sessions of laser or placebo within 8 weeks; two sessions per week (weeks 1-4) and one session per week (weeks 5-8). Pain and function scales were completed before the treatment, at the end of the fourth and eighth week of treatment, and 8 weeks after the end of treatment (follow-up). Group A revealed a significant improvement after 8 weeks of treatment in all pain and function scales. At 8-week follow-up, the improvement remained only for the pain, while for all other function outcomes the differences were not statistically significant. The results suggested that after an 8-week treatment and after a follow-up, the combination of LLLT and passive stretching exercises decreased pain more effectively than placebo LLLT along with the same passive stretching exercises in patients with Αnkylosing spondylitis. Future studies are needed to establish the relative and absolute effectiveness of the above protocol.

Effects of low-level laser therapy on joint pain, synovitis, anabolic, and catabolic factors in a progressive osteoarthritis rabbit model.

The aim of this study was to investigate the effect of low-level laser therapy (LLLT) on short-term and long-term joint pain, synovitis, anabolic, and catabolic factors in the cartilage of a rabbit model with progressive osteoarthritis (OA) induced by anterior cruciate ligament transection (ACLT). A total of 160 New Zealand white rabbits were randomly assigned into two groups (ACLT group and LLLT group). All rabbits received ACLT surgery, and 2-, 4-, 6-, and 8-week treatment after the surgery, with 20 rabbits being tested biweekly over every study period. The LLLT group received LLLT with a helium-neon (He-Ne) laser (830 nm) of 1.5 J/cm(2) three times per week, and the ACLT group received placebo LLLT with the equipment switched off. Long-term and short-term pain was tested via weight-bearing asymmetry; synovitis was assessed histologically; and knee joint cartilage was evaluated by gross morphology, histology, and gene expression analysis of anabolic and catabolic factors. The histological assessment of pain and synovitis showed that at least 6-week intermittent irradiation of LLLT could relief knee pain and control synovium inflammation. Gross morphologic inspection and histological evaluation showed that 6 weeks of LLLT could decrease cartilage damage of medical femoral condyle and 8 weeks of LLLT could decrease cartilage damage of medical and lateral femoral condyles and medical tibial plateau. Gene expression analysis revealed two results: At least 6 weeks of LLLT could decrease production of catabolic factors, for example, interleukin 1β (IL-1β), inducible nitric oxide synthase (iNOS), and MMP-3, and slow down the loss of anabolic factors, mainly TIMP-1. Eight weeks of LLLT treatment could slow down the loss of collagen II, aggrecan, and anabolic factors, mainly transforming growth factor beta (TGF-β). The study suggests that LLLT plays a protective role against cartilage degradation and synovitis in rabbits with progressive OA by virtue of the regulation of catabolic and anabolic factors in the cartilage.

Ultrasound and Laser as Stand‐Alone Therapies for Myofascial Trigger Points: A Randomized, Double‐Blind, Placebo‐Controlled Study

Ultrasound (US) and low-level laser therapy (LLLT) are commonly employed for myofascial trigger points (MTP) despite lack of evidence for usage as stand-alone treatments. The aim of the study was to determine, on MTP of the upper trapezius muscle (uTM), the effects of US and LLLT per se, as delivered in accordance with the procedures reported by surveys about their usage among physiotherapists. Design was set as a double-blind, randomized, placebo-controlled study. Sixty participants with at least one active MTP in uTM (28 women and 32 men; mean age 24.5 ± 1.44 years) were recruited and randomly assigned to one out of five groups: active US (n = 12), placebo US (n = 12), active LLLT (n = 11), placebo LLLT (n = 11) and no therapy (control, n = 14). The participants and outcome assessor were blinded to the group assignment and therapy delivered. Three outcome measures were assessed at baseline, after a 2-week treatment and 12 weeks after the end of the intervention (follow-up): pressure pain threshold, subjective pain on a numerical rating scale and muscle extensibility performing a cervical lateral flexion. All subjects assigned to the intervention groups were treated five times weekly for overall 10 treatments given. Two-way ANOVA was used to compare differences before and after intervention and among groups at each time-point. After the 2-week intervention, all groups showed pressure pain threshold, numerical rating scale and cervical lateral flexion significant improvements (p < 0.05), which were confirmed at the follow-up. When performing multiple comparisons, controls scored significantly less than both the active therapies and placebos, whereas no differences were detected between active therapies and placebos. Ultrasound and LLLT provided significant improvements in pain and muscle extensibility, which were superior to no therapy but not to placebos, thus raising concerns about the suitability, both economically and ethically, of administering such common physical modalities as stand-alone treatments in active MTP of the uTM.

둥근 어깨 자세를 가진 자의 등세모근 위 섬유의 압통점에 975-nm GaAlAs 저출력레이저 적용에 대한 즉각적인 효과

PURPOSE: The purpose of our study was to compare a 975-nm, 500-mW GaAlAs low-level laser therapy versus placebo low-level laser therapy with regard to the immediate changes on the myofascial trigger point of the dominant upper trapezius muscle in subjects with rounded shoulder posture. METHODS: Thirty-two male college students with rounded shoulder posture and shoulder pain consented to participate in the experiment. The subjects were randomly assigned to a 2-minute procedure with either an active GaAlAs low-level laser or a placebo GaAlAs low-level laser. The pressure-pain threshold and visual analog scale on tenderness at 3 kg were measured with an algometer before and after the laser treatments. RESULTS: The active GaAlAs low-level laser group showed significant changes in pressure-pain threshold and visual analog scale on tenderness at 3 kg (p0.05). CONCLUSION: An immediate effect was observed in pressure-pain threshold and visual analog scale on tenderness at 3 kg following a 2-minute application () of a 975-nm, 500-mW GaAlAs low-level laser to the myofascial trigger point of the dominant upper trapezius muscle in patients with rounded shoulder posture.

Effects of Low-Level Laser Therapy on Biceps Braquialis Muscle Fatigue in Young Women

This study aims to investigate the effects of low-level laser therapy (LLLT) on biceps brachi muscular fatigue in 20 young females. Exhausting physical activity leads to muscular fatigue, which could decrease muscular strength, and may cause impairment in motor control and muscle pain. Several biochemical and biophysical resources have been studied in an attempt to accelerate the recovery of muscle fatigue. Among these, LLLT is emphasized. Twenty subjects were randomized in one laser group and one placebo group in two sessions of a crossover design experimental procedure; the second session taking place within 7 days of the first. In the first session, subjects underwent a collection of surface electromyographic (SEMG) data of the biceps brachii muscle, followed by active or placebo LLLT at the same muscle, followed then by another EMG sample of biceps brachii. Blood samples were collected five times during the experimental procedure. Second session procedures were identical to the first, with exception of LLLT, which was the opposite of the first session. The fatigue protocol consisted of 60 sec of elbow flexion-extension movement performed with 75% of one maximum repetition. Blood lactate, EMG fatigue, and the number of elbow flexion-extension repetitions during the fatigue protocol were used to evaluate the effects of laser therapy (808 nm wavelength, 100 mW output power, power density of 35.7 W/cm(2), 70 sec each point and 7 J/point on eight points). No statistical differences were found for eletromyographic fatigue and blood lactate values between groups. Mean numbers of elbow flexion-extension repetitions were 22.6 ± 7.58 after placebo, and 25.1 ± 9.89 after active LLLT group, but these differences were not statistically significant (p=0.342). LLLT had limited effects on delaying muscle fatigue in a young female sample, although a tendency was observed in the active laser group toward showing lower electromyography fatigue of biceps brachii muscle. No intergroup differences were found in the number of muscle contractions and lactate concentration.