Effects of Short-, Medium-, and Long-Term Treatment Using Photobiomodulation Therapy Combined with Static Magnetic Field in Aging Rats.

(1) Background: We investigated the detrimental and protective effects of short-, medium, and long-term treatment with different doses of photobiomodulation therapy combined with static magnetic field (PBMT-sMF) during the aging process. (2) Methods: Rats were treated for 15, 30, and 60 weeks with 1, 3, 10, and 30 J of PBMT-sMF or a placebo control. In addition, eight young rats were not subjected to any procedure or treatment and were euthanized at six weeks old. Skin, muscle, bone, kidney, liver, and blood samples were analyzed. (3) Results: No differences between the groups in the morphology of the skin, muscle, and bone was observed. Glutamic pyruvic transaminase levels were increased in the placebo group after 30 and 60 weeks. Glutamic oxaloacetic transaminase levels were also increased in the placebo group after 30 weeks. An increase in creatinine in the PBMT-sMF 3, 10, and 30 J groups compared with that in the young control group was observed. No significant difference in urea levels between the groups was noted. Vascular endothelial growth factor increased in the PBMT-sMF 10 and 30 J groups after 15 weeks of treatment and in the PBMT-sMF 3 J after 60 weeks. Finally, vascular endothelial growth factor decreased in the PBMT-sMF 30 J group after 30 weeks of treatment. (4) Conclusions: PBMT-sMF did not have detrimental effects on the skin, muscle, bone, kidney, or liver after short-, medium-, and long-term treatments in aging rats. In addition, PBMT-sMF may have protective effects on the muscle tissue in aging rats after short- and long-term treatment.

Effects of photobiomodulation therapy (PBMT) on the management of pain intensity and disability in plantar fasciitis: systematic review and meta-analysis.

To review the effects of photobiomodulation therapy (PBMT) on pain intensity and disability in people with plantar fasciitis (PF) when compared with control conditions, other interventions, and adjunct therapies. Systematic searches were conducted in five database randomized controlled trials (RCT). We only included randomized controlled trials (RCTs) in adults with PF that compared PBMT to placebo, as well as RCTs that compared PBMT to other interventions; and as an adjunct to other therapies. The methodological quality and certainty were assessed through PEDro Scale and GRADE approach, respectively. The data of comparison were pooled and a meta-analysis was conducted when possible. Nineteen RCTs involving 1089 participants were included in this review. PBMT alone (MD = - 22.02 [- 35.21 to - 8.83]) or with exercise (MD = - 21.84 [- 26.14 to - 17.54]) improved pain intensity in short-term treatment. PBMT was superior to (extracorporeal shock wave therapy) EWST for relief of pain (MD = - 20.94 [- 32.74 to - 9.13]). In the follow-up, PBMT plus exercise had a superior to exercise therapy alone (MD = - 18.42 [- 26.48 to - 10.36]). PBMT may be superior to (ultrasound therapeutic) UST in medium- and long-term follow-ups for disability, but can be not clinically relevant. There is uncertainty that PBMT is capable of promoting improvement in disability. PBMT when used with adjuvant therapy does not enhance outcomes of interest. PBMT improves pain intensity with or without exercise. PBMT has been shown to be superior to ESWT for pain relief, but not superior to other interventions for pain intensity and disability. The evidence does not support PBMT as an adjunct to other electrotherapeutic modalities.

Pilates Method and/or Photobiomodulation Therapy Combined to Static Magnetic Field in Women with Stress Urinary Incontinence: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.

This clinical trial aims to provide evidence about the effectiveness of the Pilates method on stress urinary incontinence (SUI), as well as to elucidate the effects of photobiomodulation therapy associated with static magnetic field (PBMT/sMF) alone or associated with the Pilates Method on Pelvic floor muscle (PFM) in women affected by SUI. For that, a three-arm, parallel randomized, double-blinded, placebo-controlled trial was conducted (NCT05096936). We recruited thirty-three women diagnosed with SUI, randomly allocated to three groups: placebo PBMT/sMF plus method Pilates, PBMT/sMF active plus method Pilates and only PBMT/sMF active. The evaluation consisted of anamnesis and physical examination, muscle strength, completion of the ICIQ-SF questionnaire, and urinary loss. The evaluation of muscle strength and filling the ICIQ-SF were performed on the first and last days, while the Pad test was applied in baseline, one month, two months, and three months of intervention. We observed an increase in strength (p < 0.01), tone (p < 0.01), and quality of life (p < 0.01), in addition to a decrease in urinary lost (p < 0.01) for all groups comparing the pre and post-intervention. The PBMT/sMF alone, the Pilates, and the combination of the two therapies proved to be effective in improving the signs and symptoms of women with SUI.

Can Photobiomodulation Therapy (PBMT) Minimize Exercise-Induced Oxidative Stress? A Systematic Review and Meta-Analysis.

Oxidative stress induced by exercise has been a research field in constant growth, due to its relationship with the processes of fatigue, decreased production of muscle strength, and its ability to cause damage to the cell. In this context, photobiomodulation therapy (PBMT) has emerged as a resource capable of improving performance, while reducing muscle fatigue and muscle damage. To analyze the effects of PBMT about exercise-induced oxidative stress and compare with placebo therapy. DATA SOURCES: Databases such as PubMed, EMBASE, CINAHL, CENTRAL, PeDro, and Virtual Health Library, which include Lilacs, Medline, and SciELO, were searched to find published studies. STUDY SELECTION: There was no year or language restriction; randomized clinical trials with healthy subjects that compared the application (before or after exercise) of PBMT to placebo therapy were included. STUDY DESIGN: Systematic review with meta-analysis. DATA EXTRACTION: Data on the characteristics of the volunteers, study design, intervention parameters, exercise protocol and oxidative stress biomarkers were extracted. The risk of bias and the certainty of the evidence were assessed using the PEDro scale and the GRADE system, respectively. RESULTS: Eight studies (n = 140 participants) were eligible for this review, with moderate to excellent methodological quality. In particular, PBMT was able to reduce damage to lipids post exercise (SMD = -0.72, CI 95% -1.42 to -0.02, I2 = 77%, p = 0.04) and proteins (SMD = -0.41, CI 95% -0.65 to -0.16, I2 = 0%, p = 0.001) until 72 h and 96 h, respectively. In addition, it increased the activity of SOD enzymes (SMD = 0.54, CI 95% 0.07 to 1.02, I2 = 42%, p = 0.02) post exercise, 48 and 96 h after irradiation. However, PBMT did not increase CAT activity (MD = 0.18 CI 95% -0.56 to 0.91, I2 = 79%, p = 0.64) post exercise. We did not find any difference in TAC or GPx biomarkers. CONCLUSION: Low to moderate certainty evidence shows that PBMT is a resource that can reduce oxidative damage and increase enzymatic antioxidant activity post exercise. We found evidence to support that one session of PBMT can modulate the redox metabolism.

Photobiomodulation Therapy Combined with a Static Magnetic Field Applied in Different Moments Enhances Performance and Accelerates Muscle Recovery in CrossFit® Athletes: A Randomized, Triple-Blind, Placebo-Controlled Crossover Trial.

The ergogenic effects of photobiomodulation therapy combined with a static magnetic field (PBMT-sMF) on exercises with characteristics similar to those of CrossFit® are unknown. This study was aimed at investigating the effects of PBMT-sMF applied at different times on recovery and physical performance in CrossFit® athletes by analyzing functional aspects, muscle damage, inflammatory processes, and oxidative stress. This was a prospectively registered, triple-blinded, placebo-controlled, crossover trial. CrossFit® athletes were recruited and assigned to receive one of the four possible interventions. Each intervention included protocols before and after the exercise (referred to as the workout of the day (WOD)). The four possibilities of intervention were as follows: placebo before and after WOD (placebo), PBMT-sMF before and placebo after WOD (PBMT-sMF before), placebo before and PBMT-sMF after WOD (PBMT-sMF after), and PBMT-sMF before and after WOD (PBMT-sMF before and after). The order of possibilities for the interventions was randomized. The primary outcome was the functional test performance. The secondary outcomes were the subjective perception of exertion, muscle damage, inflammation, and oxidative stress. The outcomes were measured before the WOD; immediately after the intervention; and 1, 24, and 48 hours after the WOD. Statistical analysis was performed using repeated measures ANOVA followed by the Bonferroni post hoc test to examine the differences between the interventions at each time point. Twelve participants were randomized and analyzed for each sequence. PBMT-sMF enhanced the performance on functional tests (calculated as a percentage of change) when applied before or after WOD in the assessment performed immediately post-WOD and at 24 and 48 hours later (p < 0.05) compared to placebo and PBMT-sMF before and after WOD. In terms of the secondary outcomes, PBMT-sMF applied before or after WOD significantly decreased the creatine kinase, catalase, and superoxide dismutase activities and interleukin-6, thiobarbituric acid, and carbonylated protein levels (all p < 0.05) compared to the other possibilities of intervention. In addition, PBMT-sMF applied before and after WOD decreased creatine kinase activity at 24 hours and IL-6 levels at 24 and 48 hours compared to placebo (p < 0.05). None of the participants reported any adverse events. PBMT-sMF enhanced the performance of functional tests, decreased the levels of biochemical markers of muscle damage and inflammation, decreased oxidative stress, and increased antioxidant activity in CrossFit® athletes when applied before or after WOD.

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 Sidák'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.

Photobiomodulation Therapy Combined with Static Magnetic Field Reduces Pain in Patients with Chronic Nonspecific Neck and/or Shoulder Pain: A Randomized, Triple-Blinded, Placebo-Controlled Trial.

Photobiomodulation therapy (PBMT) has been used to treat patients with chronic neck and/or shoulder pain. However, it is unknown whether the concurrent use of PBMT and static magnetic field (PBMT-sMF) also has positive effects in these patients. The aim of this study was to investigate the effects of PBMT-sMF versus placebo on pain intensity, range of motion (ROM) and treatment satisfaction in patients with chronic nonspecific neck and/or shoulder pain. A randomized controlled trial, with blinded assessors, therapists and patients was carried out. Seventy-two patients with chronic nonspecific neck and/or shoulder pain were randomized to either active PBMT-sMF (n = 36) or placebo PBMT-sMF (n = 36). Patients were treated twice weekly, over 3 weeks. Primary outcome was pain intensity, measured 15 min after the last treatment session and at 24-, 48-, 72-h, and 7-days after the last treatment. Secondary outcomes were ROM, patient' treatment satisfaction, and adverse effects. PBMT-sMF was able to reduce pain intensity in all time points tested compared to placebo (p < 0.05). There was no difference between groups in the secondary outcomes (p > 0.05). Our results suggest that PBMT-sMF is better than placebo to reduce pain in patients with chronic nonspecific neck and/or shoulder pain at short-term.

Photobiomodulation Therapy Combined with Static Magnetic Field (PBMT-SMF) on Spatiotemporal and Kinematics Gait Parameters in Post-Stroke: A Pilot Study.

BACKGROUND: Gait deficit is a major complaint in patients after stroke, restricting certain activities of daily living. Photobiomodulation therapy combined with a static magnetic field (PBMT-SMF) has been studied for several diseases, and the two therapies are beneficia. However, their combination has not yet been evaluated in stroke. Therefore, for PBMT-SMF to be used more often and become an adjunctive tool in the rehabilitation of stroke survivors at physical therapy rehabilitation centers and clinics, some important aspects need to be clarified. PURPOSE: This study aimed to test different doses of PBMT-SMF, to identify the ideal dose to cause immediate effects on the spatiotemporal and kinematic variables of gait in post-stroke patients. METHODS: A randomized, triple-blinded, placebo-controlled crossover pilot study was performed. A total of 10 individuals with hemiparesis within 6 months to 5 years since the occurrence of stroke, aged 45-60 years, were included in the study. Participants were randomly assigned and treated with a single PBMT-SMF dose (sham, 10 J, 30 J, or 50 J) on a single application, with one dose per stage at 7-day intervals between stages. PBMT-SMF was applied with a cluster of 12 diodes (4 of 905 nm laser, 4 of 875 nm LEDs, and 4 of 640 nm LEDs, SMF of 35 mT) at 17 sites on both lower limbs after baseline evaluation: plantar flexors (2), knee extensors (9), and flexors (6). The primary outcome was self-selected walking speed, and the secondary outcomes were kinematic parameters. Gait analysis was performed using SMART-D 140® and SMART-D INTEGRATED WORKSTATION®. The outcomes were measured at the end of each stage after the single application of each PBMT-SMF dose tested. RESULTS: No significant differences (p > 0.05) in spatiotemporal variables were observed between the different doses, compared with the baseline evaluation. However, differences (p < 0.05) were observed in the kinematic variable of the hip in the paretic and non-paretic limbs, specifically in the minimum flexion/extension angulation during the support phase (HMST-MIN) in doses 10 J, 30 J, and 50 J. CONCLUSIONS: A single application of PBMT-SMF at doses of 10 J, 30 J, and 50 J per site of the lower limbs did not demonstrate positive effects on the spatiotemporal variables, but it promoted immediate effects in the kinematic variables of the hip (maximum and minimum flexion/extension angulation during the support phase) in the paretic and non-paretic limbs in post-stroke people.

Photobiomodulation therapy applied during an exercise-training program does not promote additional effects in trained individuals: A randomized placebo-controlled trial.

BACKGROUND: Previous studies have shown positive results of photobiomodulation (PBM) for improving performance and accelerating post-exercise recovery. However, the effects of PBM in healthy individuals who underwent a neuromuscular adaptation training remain unclear. OBJECTIVE: To investigate the effects of PBM during a training program combining sprints and explosive squats exercises on clinical, functional, and systemic outcomes in trained healthy individuals compared to a placebo intervention and a control. METHODS: We conducted a randomized placebo-controlled trial. Healthy males were randomly assigned to three groups: active PBM (30 J per site), placebo, or control (passive recovery). The participants performed a six-week (12 sessions) of a training program consisting of a combination of sprints and squats with recovery applied between sprints and squats. To prevent the influence of the primary neuromuscular adaptation to exercise on the results, all participants had to participate in a period of six weeks of exercise training program. Functional, clinical, and psychological outcomes and vascular endothelial growth factor (VEGF) were assessed at baseline and after six weeks. Results are expressed as mean difference (MD) and 95% confidence intervals (CI). RESULTS: Thirty-nine healthy male volunteers (aged 18-30 years; body mass index 23.9 ±â€¯3 kg/m²) were recruited. There was no significant time by group interaction, and no significant effect of group, but there was a significant effect of time for maximal voluntary isometric contraction (primary outcome) (MD=22 Nm/kg; 95%CI: 3.9, 40) and for squat jump (MD=1.6 cm; 95CI%: 0.7, 2.5). There was no significant interaction (time*group), time, or group effect for the other outcomes. CONCLUSION: The addition of PBM to a combined training performed for six weeks in previously trained individuals did not result in additional benefits compared to placebo or no additional intervention.

Effects of Transcranial Direct Current Stimulation on Muscle Fatigue in Recreational Runners: Randomized, Sham-Controlled, Triple-Blind, Crossover Study-Protocol Study.

OBJECTIVES: The aim of this study is to evaluate the effects of transcranial direct current stimulation (tDCS) on central and peripheral fatigue in recreational runners. DESIGN: This is a clinical randomized, sham-controlled, triple-blind, crossover study. Twenty adult runners will be randomized on the first day of the intervention to receive active or sham tDCS before fatigue protocol. After 1 wk, the participants will receive the opposite therapy to the one that they received on the first day. The tDCS, 2 mA, will be applied for 20 mins over the motor cortex. The fatigue protocol will be performed after tDCS, in which the participant should perform concentric knee flexion/extension contractions until reaching three contractions at only 50% of maximum voluntary contraction. Central fatigue will be evaluated with the motor evoked potential of the quadriceps muscle; peripheral fatigue with the peak torque (N.m) using an isokinetic dynamometer; the electrical activity of the quadriceps muscle using surface electromyography (Hz); blood lactate level (mmol/L); and the subjective perception of effort (Borg scale). All evaluations will be repeated before and after the interventions. CONCLUSION: This study will evaluate the effect of tDCS on fatigue in runners, possibly determining an application protocol for this population.

Comparison between cryotherapy and photobiomodulation in muscle recovery: a systematic review and meta-analysis.

The purpose of this study is to compare the effect of photobiomodulation therapy (PBMT) and cryotherapy (CRT) on muscle recovery outcomes. These searches were performed in PubMed, PEDro, CENTRAL, and VHL (which includes the Lilacs, Medline, and SciELO database) from inception to June 2021. We included randomized clinical trials involved healthy human volunteers (> 18 years) underwent an intervention of PBMT and CRT, when used in both isolated form post-exercise. Standardized mean differences (SMD) or mean difference (MD) with 95% confidence interval were calculated and pooled in a meta-analysis for synthesis. The risk of bias and quality of evidence were assessed through Cochrane risk-of-bias tool and GRADE system. Four articles (66 participants) with a high to low risk of bias were included. The certainty of evidence was classified as moderate to very low. PBMT was estimated to improve the muscle strength (SMD = 1.73, CI 95% 1.33 to 2.13, I2 = 27%, p < 0.00001), reduce delayed onset muscle soreness (MD: - 25.69%, CI 95% - 34.42 to - 16.97, I2 = 89%, p < 0.00001), and lower the concentration of biomarkers of muscle damage (SMD = - 1.48, CI 95% - 1.93 to - 1.03, I2 = 76%, p < 0,00,001) when compared with CRT. There was no difference in oxidative stress and inflammatory levels. Based on our findings, the use of PBMT in muscle recovery after high-intensity exercise appears to be beneficial, provides a clinically important effect, and seems to be the best option when compared to CRT.

Immediate effects of photobiomodulation therapy combined with a static magnetic field on the subsequent performance: a preliminary randomized crossover triple-blinded placebo-controlled trial.

There is evidence about the effects of photobiomodulation therapy (PBMT) alone and combined with a static magnetic field (PBMT-sMF) on skeletal muscle fatigue, physical performance and post-exercise recovery in different types of exercise protocols and sports activity. However, the effects of PBMT-sMF to improve the subsequent performance after a first set of exercises are unknown. Therefore, the aim of this study was to investigate the effects of PBMT-sMF, applied between two sets of exercises, on the subsequent physical performance. A randomized, crossover, triple-blinded (assessors, therapist, and volunteers), placebo-controlled trial was carried out. Healthy non-athlete male volunteers were randomized and treated with a single application of PBMT-sMF and placebo between two sets of an exercise protocol performed on isokinetic dynamometer. The order of interventions was randomized. The primary outcome was fatigue index and the secondary outcomes were total work, peak work, and blood lactate levels. Twelve volunteers were randomized and analyzed to each sequence. PBMT-sMF decreased the fatigue index compared to the placebo PBMT-sMF at second set of the exercise protocol (MD = -6.08, 95% CI -10.49 to -1.68). In addition, PBMT-sMF decreased the blood lactate levels post-intervention, and after the second set of the exercise protocol compared to placebo (p<0.05). There was no difference between PBMT-sMF and placebo in the remaining outcomes tested. Volunteers did not report adverse events. Our results suggest that PBMT-sMF is able to decrease skeletal muscle fatigue, accelerating post-exercise recovery and, consequently, increasing subsequent physical performance when applied between two sets of exercises.

Multi-Wavelength Photobiomodulation Therapy Combined with Static Magnetic Field on Long-Term Pulmonary Complication after COVID-19: A Case Report.

INTRODUCTION: Photobiomodulation therapy, alone (PBMT) or combined with a static magnetic field (PBMT-sMF), has been demonstrated to be effective in the regeneration of tissues, modulation of inflammatory processes, and improvement in functional capacity. However, the effects of PBMT-sMF on the pulmonary system and COVID-19 patients remain scarce. Therefore, in this case report, we demonstrated the use of PBMT-sMF for peripheral oxygen saturation, pulmonary function, massive lung damage, and fibrosis as a pulmonary complication after COVID-19. CASE REPORT: A 53-year-old Mexican man who presented with decreased peripheral oxygen saturation, massive lung damage, and fibrosis after COVID-19 received PBMT-sMF treatment once a day for 45 days. The treatment was irradiated at six sites in the lower thorax and upper abdominal cavity and two sites in the neck area. We observed that the patient was able to leave the oxygen support during the treatment, and increase his peripheral oxygen saturation. In addition, the patient showed improvements in pulmonary severity scores and radiological findings. Finally, the patient presented with normal respiratory mechanics parameters in the medium-term, indicating total pulmonary recovery. CONCLUSIONS: The use of PBMT-sMF may potentially lead to safe treatment of and recovery from pulmonary complications after COVID-19, with regard to the structural and functional aspects.

Effects of Photobiomodulation Therapy Combined with Static Magnetic Field in Severe COVID-19 Patients Requiring Intubation: A Pragmatic Randomized Placebo-Controlled Trial.

PURPOSE: We aimed to investigate the effects of photobiomodulation therapy combined with static magnetic field (PBMT-sMF) on the length of intensive care unit (ICU) stay and mortality rate of severe COVID-19 patients requiring invasive mechanical ventilation and assess its role in preserving respiratory muscles and modulating inflammatory processes. PATIENTS AND METHODS: We conducted a prospectively registered, triple-blinded, randomized, placebo-controlled trial of PBMT-sMF in severe COVID-19 ICU patients requiring invasive mechanical ventilation. Patients were randomly assigned to receive either PBMT-sMF or a placebo daily throughout their ICU stay. The primary outcome was length of ICU stay, defined by either discharge or death. The secondary outcomes were survival rate, diaphragm muscle function, and the changes in blood parameters, ventilatory parameters, and arterial blood gases. RESULTS: Thirty patients were included and equally randomized into the two groups. There were no significant differences in the length of ICU stay (mean difference, MD = -6.80; 95% CI = -18.71 to 5.11) between the groups. Among the secondary outcomes, significant differences were observed in diaphragm thickness, fraction of inspired oxygen, partial pressure of oxygen/fraction of inspired oxygen ratio, C-reactive protein levels, lymphocyte count, and hemoglobin (p < 0.05). CONCLUSION: Among severe COVID-19 patients requiring invasive mechanical ventilation, the length of ICU stay was not significantly different between the PBMT-sMF and placebo groups. In contrast, PBMT-sMF was significantly associated with reduced diaphragm atrophy, improved ventilatory parameters and lymphocyte count, and decreased C-reactive protein levels and hemoglobin count. TRIAL REGISTRATION NUMBER CLINICAL TRIALSGOV: NCT04386694.

Effectiveness of Low-Level Laser Therapy Associated with Strength Training in Knee Osteoarthritis: Protocol for a Randomized Placebo-Controlled Trial.

Physical activity and low-level laser therapy (LLLT) can reduce knee osteoarthritis (KOA) inflammation. We are conducting a randomized placebo-controlled trial to investigate the long-term effectiveness of LLLT combined with strength training (ST) in persons with KOA, since it, to our knowledge, has not been investigated before. Fifty participants were enrolled. LLLT and ST was performed 3 times per week over 3 and 8 weeks, respectively. In the LLLT group, 3 Joules of 904 nm wavelength laser was applied to 15 spots per knee (45 Joules/knee/session). The primary outcomes are pain during movement, at night and at rest (Visual Analogue Scale) and global pain (Knee injury and Osteoarthritis Outcome Score, KOOS) pain subscale. The secondary outcomes are KOOS disability and quality-of-life, analgesic usage, global health change, knee active range of motion, 30 s chair stand, maximum painless isometric knee extension strength, knee pain pressure threshold and real-time ultrasonography-assessed suprapatellar effusion, meniscal neovascularization and femur cartilage thickness. All the outcomes are assessed 0, 3, 8, 26 and 52 weeks post-randomization, except for global health change, which is only evaluated at completed ST. This study features the blinding of participants, assessors and therapists, and will improve our understanding of what occurs with the local pathophysiology, tissue morphology and clinical status of persons with KOA up to a year after the initiation of ST and a higher 904 nm LLLT dose than in any published trial on this topic.

Post-resistance exercise photobiomodulation therapy has a more effective antioxidant effect than pre-application on muscle oxidative stress.

This study evaluated the effect of photobiomodulation therapy (PBMt) before or after a high-intensity resistance exercise (RE) session on muscle oxidative stress. Female Wistar rats were assigned to one of the following groups: Sham (non-exercised, undergoing placebo-PBMt); NLRE (exercised, undergoing placebo-PBMt); PBMt + RE (pre-exercise PBMt); RE + PBMt (post-exercise PBMt). The RE comprised four climbs bearing the maximum load with a 2 min rest between each climb. An 830-nm aluminum gallium arsenide diode laser (100 mW; 0.028 cm2; 3.57 mW/cm2; 142.8 J/cm2; 4 J; Photon Laser III, DMC, São Paulo, Brazil) was applied 60 s before or after RE in gastrocnemius muscles. Analyses were performed at 24 h after RE: lipoperoxidation using malondialdehyde (MDA) and protein oxidation (OP) on Western blot. Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activity were spectrophotometrically assessed. Nitric oxide (NO) level was determined by the Griess reaction. The MDA and OP levels were significantly higher in the NLRE group. Increased OP was prevented in all PBMt groups; however, increased MDA was prevented only in the RE + PBMT group. The RE + PBMt group had higher SOD activity compared to all other groups. A higher GPx activity was observed only in the PBMT + RE compared to Sham group, and CAT activity was reduced by RE, without PBMt effect. NO levels were unchanged with RE or PBMt. Therefore, PBMt application after a RE section has a more potent antioxidant effect than previous PBMt. Rats submitted to post-RE PBMt illustrated prevention of increased lipoperoxidation and protein oxidation as well as increased SOD activity. The photobiomodulation can attenuate oxidative stress induced by resistance exercise. A more evident benefit shows to be obtained with the application after exercise, in which it has increased the activity of superoxide dismustase.

Photobiomodulation therapy is not better than placebo in patients with chronic nonspecific low back pain: a randomised placebo-controlled trial.

ABSTRACT: Photobiomodulation therapy (PBMT) has been used in several musculoskeletal disorders to reduce pain, inflammation, and promoting tissue regeneration. The current evidence about the effects of PBMT on low back pain (LBP) is still conflicting. We aimed to evaluate the effects of PBMT against placebo on pain intensity and disability in patients with chronic nonspecific LBP. This was a prospectively registered, randomised placebo-controlled trial, with blinded patients, therapists, and assessors. The study was conducted on an outpatient physical therapy clinic in Brazil, between April 2017 and May 2019. A total of 148 patients with chronic nonspecific LBP were randomised to either active PBMT (n = 74) or placebo (n = 74). Patients from both groups received 12 treatment sessions, 3 times a week, for 4 weeks. Patients from both groups also received an educational booklet based on "The Back Book." Clinical outcomes were measured at baseline and at follow-up appointments at 4 weeks, 3, 6, and 12 months after randomisation. The primary outcomes were pain intensity and disability measured at 4 weeks. We estimated the treatment effects using linear mixed models following the principles of intention-to-treat. There was no clinical important between-group differences in terms of pain intensity (mean difference = 0.01 point; 95% confidence interval = -0.94 to 0.96) and disability (mean difference = -0.63 points; 95% confidence interval = -2.23 to 0.97) at 4 weeks. Patients did not report any adverse events. Photobiomodulation therapy was not better than placebo to reduce pain and disability in patients with chronic nonspecific LBP.

Photobiomodulation Therapy is Able to Modulate PGE2 Levels in Patients With Chronic Non-Specific Low Back Pain: A Randomized Placebo-Controlled Trial.

BACKGROUND AND OBJECTIVES: Non-specific low back pain (LBP) is responsible for triggering increased biomarkers levels. In this way, photobiomodulation therapy (PBMT) may be an interesting alternative to treat these patients. One of the possible biological mechanisms of PBMT involved to decrease pain intensity in patients with musculoskeletal disorders is modulation of the inflammatory mediators' levels. The aim of this study was to evaluate the effects of PBMT compared with placebo on inflammatory mediators' levels and pain intensity in patients with chronic non-specific LBP. STUDY DESIGN/MATERIALS AND METHODS: A prospectively registered, randomized triple-blinded (volunteers, therapists, and assessors), placebo-controlled trial was performed. Eighteen patients with chronic non-specific LBP were recruited and treated with a single session of active PBMT or placebo PBMT. The primary outcome of the study was serum prostaglandin E2 levels and the secondary outcomes were tumor necrosis factor-α, interleukin-6 levels, and pain intensity. All outcomes were measured before and after 15 minutes of treatment session. RESULTS: PBMT was able to decrease prostaglandin E2 levels at post-treatment compared with placebo, with a mean difference of -1470 pg/ml, 95% confidence interval -2906 to -33.67 in patients with LBP. There was no difference between groups in the other measured outcomes. Patients did not report any adverse events. CONCLUSION: Our results suggest that PBMT was able to modulate prostaglandin E2 levels, indicating that this may be one of the mechanisms involved in the analgesic effects of PBMT in patients with LBP. Trial registration number (ClinicalTrials.gov): NCT03859505. Lasers Surg. Med. © 2020 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals, Inc.

Effect of photobiomodulation therapy on the proliferation phase and wound healing in rats fed with an experimental hypoproteic diet.

Photobiomodulation therapy (PBMT) has been indicated for enforcement on healing skin wounds. This study evaluated the effects of PBMT on the healing of skin wounds during the proliferation phase in rats with a hypoproteic diet. Rats were randomized to one of the following groups (n = 10 per group): (i) injured normoproteic (25% protein) not subjected to PBMT; (ii) injured normoproteic who received PBMT; (iii) injured hypoproteic (8% protein) not subjected to PBMT; and (iv) injured hypoproteic who received PBMT. Rats were submitted to skin wounds and then treated with PBMT (low-level laser therapy: 660 nm, 50 mW, 1.07 W/cm2, 0.028 cm2, 72 J/cm2, 2 J). Analyses were performed at 7 and 14 days of follow-up: semi-quantitative histopathologic analysis, collagen type I and III expressions, immunohistochemical marking for matrix metalloproteinases-3 (MMP-3) and (matrix metalloproteinases-9) MMP-9, and mechanical resistance test. There were significant differences between the normoproteic groups and their respective treated groups (p < 0.05), as well as to treated and untreated hypoproteic groups in histopathologic analysis semi-quantitatively and immunohistochemistry for MMP-3 and 9, in which PBMT was able to decrease immunostaining. Moreover, there was a decrease in collagen deposition with the statistical difference (p < 0.05) for both collagen types III and I. In conclusion, PBMT application was proved effective in the treatment of cutaneous wounds in rats submitted to a hypoproteic diet. These alterations were more salient in the proliferation stage with the reduction of metalloproteinases providing better mechanical resistance of the injured area in the remodeling phase with an intensification of type I collagen.