Photobiomodulation using high- or low-level laser irradiations in patients with lumbar disc degenerative changes: disappointing outcomes and remarks

Effects of MLS Laser on pain, function, and disability in chronic non-specific low back pain: A double-blind placebo randomized-controlled trial

BACKGROUND

Among non-pharmacological interventions, Multiwave Locked System (MLS) Laser therapy has been used in patients with several musculoskeletal pathologies and in combination with other therapeutical interventions. The effects of sole MLS therapy on pain and function in patients with chronic non-specific low-back pain are unknown.

OBJECTIVE

The objective of this study was to investigate the effects of MLS Laser therapy on pain, function, and disability in patients with chronic non-specific low back pain in comparison to a placebo treatment group.

METHODS

Forty-five patients were randomized into two groups: the MLS Laser group and the Sham Laser group, undergoing 8 sessions of either a MLS Laser therapy or a Sham Laser therapy, respectively. At the beginning of the therapy (T0), at the end of the therapy (T1), and 1 month after the end of therapy (T2) patients were assessed for low back pain (by means of a VAS scale), function (by means of kinematic and electromyographic assessment of a forward bending movement) and self-reported disability (by means of the Roland-Morris and Oswestry Disability questionnaires).

RESULTS

There was a significant reduction of pain and disability in both groups at T1 and T2 in comparison with T0. At T2 patients in the MLS group showed a significantly lower pain in comparison with patients in the Sham group (VAS = 2.2 ± 2 vs. 3.6 ± 2.4; p< 0.05). No differences between the two groups were found for function and disability.

CONCLUSION

Both MLS Laser and Sham Laser therapies lead to a significant and comparable reduction in pain and disability in patients with chronic non-specific low back pain. However, one month after treatment, MLS Laser therapy has been found to be significantly more effective in reducing pain as compared to sham treatment.

High-intensity laser therapy in low back pain management: a systematic review with meta-analysis

Low back pain (LBP) is a widespread health issue affecting people globally and is the second leading cause of missed workdays. High-intensity laser therapy (HILT) promises to decrease pain intensity in LBP patients. The aim of this work was to evaluate the effect of HILT in adult LBP patients. We searched for randomized controlled studies (RCTs) published before January of 2023. Our primary outcome was pain intensity, while our secondary outcomes included disability and flexibility scores. We synthesized the evidence using RevMan v.5.4 and assessed methodological quality with the Oxford/Jadad scale and the Cochrane collaboration's risk of bias tool 1. The model favors the HILT group over the control group in terms of pain intensity after treatment (MD with 95% CI is -1.65 [-2.22, -1.09], p-value < 0.00001, I2=67%), Oswestry disability index (MD with 95% CI is -0.67 [-1.22, -0.12], p-value = 0.02, I2=73%), and Roland disability index (MD with 95% CI is -1.36 [-1.76, -0.96], p-value <0.00001, I2=0%). The patients in the high-intensity laser therapy had statistically significantly lower (low back) pain intensity compared to the patients in the control group. Based on three RCTs, our model also showed the positive effect of the HILT on LBP in terms of the Oswestry disability index and Roland disability index.

Spread of the Optical Power Emission of Three Units Each of Two Different Laser Therapy Devices Used in Sports Medicine, Which Cannot Be Assessed by the Users, Shown by Means of High-Fidelity Laser Measurement Technology

Laser therapy devices (LTDs) operating with near-infrared laser light are increasingly being used in sports medicine. For several reasons, users cannot evaluate whether or not such devices emit laser beams according to the specifications provided by the manufacturer and the settings of the device. In this study, the laser beams from two different LTDs that can be used in sports medicine were thoroughly characterized by measuring the emitted power, pulse shapes and lengths and spatial intensity distributions using professional, high-fidelity laser measurement technology. This was repeated for three units of each LDT independently to distinguish problems of individual units from potential intrinsic instrument design errors. The laser beams from the units of one LTD agreed with the settings of the device, with the measured average power for these units being within 3.3% of the set power. In contrast, the laser beams from the units of the other LTD showed large deviations between the settings and the actual emitted light. This device came with three laser diodes that could be used independently and simultaneously. The average power differed greatly between the units as well as between the laser diodes within each unit. Some laser diodes emitted essentially no light, which could lead to a lack of treatment for patients. Other laser diodes emitted much more power than set at the device (up to 230%), which could result in skin irritations or burning of patients. These findings indicate a need for better standardization and consistency of therapeutic laser light sources.

High-Intensity Laser Therapy for Musculoskeletal Disorders: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

High-intensity laser therapy (HILT) is one of the therapeutic approaches used in the treatment of musculoskeletal disorders (MSD). The main objective of this study was to examine the effectiveness of HILT for reducing pain and improving functionality in people with MSD. Ten databases were systematically searched for randomized trials published up to 28 February 2022. Randomized clinical trials (RCTs) assessing the effectiveness of HILT on MSD were included. The main outcome measures were pain and functionality. In total, 48 RCTs were included in the qualitative synthesis and 44 RCTs in the quantitative analysis. HILT showed a decrease on the pain VAS (mean difference (MD) = -1.3 cm; confidence interval (CI) 95%: -1.6 to -1.0) and an improvement in functionality (standardized mean difference (SMD) = -1.0; CI95%: -1.4 to -0.7), with low and moderate quality of evidence, respectively. A greater effect was observed when compared with control than with other conservative treatments, both on pain (χ2 = 20.6; p < 0.001) and functionality (χ2 = 5.1; p = 0.02). Differences in the effectiveness of HILT were found depending on the location (χ2 = 40.1 p < 0.001), with further improved functionality in MSD of the knee and shoulder. HILT is an effective treatment for improving pain, functionality, range of motion, and quality of life in people with MSD, although these findings must be treated with caution due to the high risk of bias in the studies. Further clinical trials should be well designed to lower the risk of bias.

Low-Level Laser Therapy Induces Melanoma Tumor Growth by Promoting Angiogenesis

The effects of low-level laser therapy (LLLT) on tumor growth are inconsistent. In this study, we investigated the effects of LLLT on melanoma tumor growth and angiogenesis. C57/BL6 mice were challenged with B16F10 melanoma cells and treated with LLLT for 5 consecutive days; untreated mice were used as controls. Tumor weight, angiogenesis, immunohistochemistry, and protein levels were compared between the treated and untreated mice. In an in vitro experiment, B16F10 cells were treated with LLLT. Proteins were extracted and subjected to Western blot analysis for analyzing signaling pathways. Compared with the findings in the untreated mice, tumor weight substantially increased in the treated mice. Both immunohistochemical and Western blot analyses revealed markedly increased levels of CD31, a biomarker of vascular differentiation, in the LLLT group. In B16F10 cells, LLLT considerably induced the phosphorylation of extracellular signal-regulated kinase (ERK), which, in turn, phosphorylated p38 mitogen-activated protein kinase (MAPK). Furthermore, LLLT induced the expression of vascular endothelial growth factor, but not hypoxia-inducible factor-1α, through the ERK/p38 MAKP signaling pathways. Our findings indicate that LLLT induces melanoma tumor growth by promoting angiogenesis. Therefore, it should be avoided in patients with melanoma.

TECAR Therapy Associated with High-Intensity Laser Therapy (Hilt) and Manual Therapy in the Treatment of Muscle Disorders: A Literature Review on the Theorised Effects Supporting Their Use

Background: It has been estimated that between 30 and 50 per cent of all injuries that take place throughout participation in a sport are the consequence of soft tissue injuries, and muscle injuries are the primary cause of physical disability. Methods: The current literature review was designed between October 2021 and April 2022, according to the PRISMA standards, using the PubMed, Scopus, and Web of Science databases. At the screening stage, we eliminated articles that did not fit into the themes developed in all subchapters of the study (n = 70), articles that dealt exclusively with orthopaedics (n = 34), 29 articles because the articles had only the abstract visible, and 17 articles that dealt exclusively with other techniques for the treatment of musculoskeletal disorders. The initial search revealed 343 titles in the databases, from which 56 duplicate articles were automatically removed, and 2 were added from other sources. Results: The combination of these three techniques results in the following advantages: It increases joint mobility, especially in stiff joints, it increases the range of motion, accelerates tissue repair, improves tissue stability, and extensibility, and it reduces soft tissue inflammation (manual therapy). In addition, it decreases the concentration of pro-inflammatory mediators and improves capillary permeability, resulting in the total eradication of inflammation (HILT). It warms the deep tissues, stimulates vascularity, promotes the repose of tissues (particularly muscle tissue), and stimulates drainage (TECAR). Conclusions: TECAR therapy, combined with manual therapy and High-Intensity Laser therapy in treating muscle diseases, presented optimal collaboration in the recovery process of all muscle diseases.

Effectiveness of High Power Laser Therapy on Pain and Isokinetic Peak Torque in Athletes with Proximal Hamstring Tendinopathy: A Randomized Trial

Athletes such as long-distance runners, sprinters, hockey, and/or football players may have proximal hamstring tendinopathy (PHT). Laser therapy has been shown to be effective in tendinopathies. High power laser therapy (HPLT) is used for the treatment of several musculoskeletal conditions; however, its efficacy on PHT has not been investigated. This study is aimed at examining the effects of HPLT on pain and isokinetic peak torque (IPT) in athletes with PHT. The two-arm comparative pretest-posttest experimental design was used with random allocation of 36 athletes aged 18-35 years into two groups (experimental and conventional group). The experimental group included the application of HPLT for 3 weeks. The conventional group included treatment with a conventional physiotherapy program including ultrasound therapy, moist heat pack, and home exercises for a total of 3 weeks. Pain and IPT of the hamstring muscle were measured before and after the application of the intervention. Pain score decreased, and IPT increased significantly (p < 0.05) after application of HPLT, by 61.26% and 13.18%, respectively. In the conventional group, a significant difference (p < 0.05) was observed in pain scores only, which decreased by 41.14%. No significant difference (p > 0.05) was observed in IPT in the conventional group. When HPLT was compared with conventional physiotherapy, a significant difference was found in pain scores only. HPLT for 3 weeks was found to be effective in improving pain in athletes with PHT. However, no significant difference was found between HPLT and conventional physiotherapy (US, moist heat, and home exercises) in improving the IPT of the hamstring muscle.

Utilization of the 1064 nm Wavelength in Photobiomodulation: A Systematic Review and Meta-Analysis

Introduction: Photobiomodulation or low-level laser therapy (LLLT;<0.5 W) has been used as a non-invasive treatment for various medical indications. Short (visible; 635-650 nm) and longer (invisible; 810-850 nm and 915-980 nm) near-infrared wavelengths have been commonly used, but power setting deficiencies or incorrect wavelength settings can cause negative outcomes. The 1064 nm wavelength as the longest wavelength is a relative newcomer in high-powered (>0.5 W) laser photobiomodulation therapy (HPL-PBMT) with unique biophysical characteristics. Methods: A comprehensive search of 2016-2021 PubMed, Google Scholar, and Cochrane databases for "photobiomodulation" restricted to clinical trials for patients with a medical diagnosis was done. "1064 nm" content was identified and restricted to high-powered lasers (>0.5 watt). Cohen's d was calculated for the effect size and the difference was determined as a measure of relative 1064 nm HPL-PBMT efficacy. Results: The 22 independent studies meeting inclusion criteria focused on knee arthropathies, spine, shoulder/elbow, wound, gynecological, or osteoporosis with evaluation of pain, function, quality of life, range of motion (ROM), and anatomy. Pain was reduced with statistical significance (P<0.05) in 90% of study assessments (n=20) and 100% of studies focused on the knee (n=6). Of 18 studies assessing functional outcome measures, 100% demonstrated statistically significant improvements. Follow-up assessments up to 6 months in 5 knee arthritis studies revealed long-term pain reduction after cessation of treatment. Improvements in wound healing, bone mineral density, and knee cartilage thickness were demonstrated. The largest effect sizes observed were pain reduction in knee arthritis (average Cohen's d effect size=2.46). Conclusion: These studies have established that 1064 nm HPL-PBMT can effectively reduce pain, increase ROM, increase functional scores, and increase the quality of life for knee osteoarthritis and spinal disorders, with limitations. More studies are needed for clinical validation of single-trial data detecting changes in musculoskeletal conditions, cartilage thickness and bone density.

A Randomised-Controlled Clinical Study Examining the Effect of High-Intensity Laser Therapy (HILT) on the Management of Painful Calcaneal Spur with Plantar Fasciitis

Calcaneal spur and plantar fasciitis are the most common causes of plantar heel pain. There are many effective physical modalities for treating this musculoskeletal disorder. So far, the are no clear recommendations confirming the clinical utility of high-intensity laser therapy (HILT) in the management of painful calcaneal spur with plantar fasciitis. This study aimed to evaluate the effectiveness of HILT in pain management in patients with calcaneal spur and plantar fasciitis. A group of 65 patients was assessed for eligibility based on the CONSORT guidelines. This study was prospectively registered in the Australian New Zealand Clinical Trial Registry platform (registration number ACTRN12618000744257, 3 May 2018). The main eligibility criteria were: cancer, pregnancy, electronic and metal implants, acute infections, impaired blood coagulation, cardiac arrhythmias, taking analgesic or anti-inflammatory medications, non-experience of heel pain, or presence of other painful foot conditions. Finally, 60 patients were randomly assigned into two groups: study group (n = 30, mean age 59.9 ± 10.1), treated with HILT (7 W, 149.9 J/cm², 1064 nm, 4496 J, 12 min), and placebo-controlled group (n = 30, mean age 60.4 ± 11.9), treated with sham HILT therapy. Both groups received ultrasound treatments (0.8 W/cm², 1 MHz frequency, 100% load factor, 5 min). Treatment procedures were performed once a day, five times per week for three weeks (total of 15 treatment sessions). Study outcomes focused on pain intensity and were assessed before (M1) and after (M2) the treatment as well as after 4 (M3) and 12 (M4) weeks using the Visual Analogue Scale (VAS) and the Laitinen Pain Scale (LPS). According to VAS, a statistically significant decrease in the study group was observed between M1 and M2 by 3.5 pts, M1 and M3 by 3.7 pts, and M1 and M4 by 3.2 pts (p < 0.001). On the other hand, the control group showed a statistically significant decrease (p < 0.001) between M1 and M2 by 3.0 pts, M1 and M3 by 3.4 pts, and M1 and M4 by 3.2 pts. According to LPS, a statistically significant decrease in the study group was observed between M1 and M2 by 3.9 pts, M1 and M3 by 4.2 pts, and M1 and M4 by 4.0 pts (p < 0.001). On the other hand, the control group showed a statistically significant decrease between M1 and M2 by 3.2 pts (p = 0.002), M1 and M3 by 4.0 pts (p < 0.001), and M1 and M4 by 3.9 pts (p < 0.001). However, there were no statistically significant differences between the groups in VAS and LPS (p > 0.05). In conclusion, the HILT does not appear to be more effective in pain management of patients with calcaneal spurs and plantar fasciitis than the conservative standard physiotherapeutic procedures.

Photobiomodulation Therapy to Promote Angiogenesis in Diabetic Mice with Hindlimb Ischemia

Objective: To assess whether photobiomodulation therapy (PBMT) induces angiogenesis in diabetic mice with hindlimb ischemia (HLI). Background: Patients with diabetes mellitus (DM) are at high risk of developing peripheral arterial disease (PAD) in the lower extremities. PBMT has been shown to promote angiogenesis both in vitro and in vivo and could be a treatment for DM patients with PAD. Methods: Femoral artery ligation/excision in mice was performed to induce HLI as an animal model of PAD. PBMT at a dose of 660 nm and 1.91 J/cm² was delivered for 10 min on 5 consecutive days after the HLI surgery. Control mice received HLI only. Mice in the DM group were injected with streptozocin to induce diabetes before HLI surgery. Mice in the laser and DM+ laser groups received both HLI and PBMT, and the latter group had induced DM. After the laser treatment, lower limb blood flow was evaluated by laser Doppler. The capillary density and CD31 were analyzed by immunofluorescence staining, and protein levels of vascular endothelial growth factor (VEGF)-A, hypoxia-inducible factor-1α (HIF-1α), inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and extracellular signal-regulated kinases (ERK) were measured by Western blotting of tissue samples. Results: Compared with the control and DM mice, the laser and DM+ laser groups had more than double the capillary density and blood perfusion rate. Levels of CD31 and VEGF-A proteins in groups that received laser were increased by 1.9- to 3.2-fold compared with groups that did not undergo laser treatment. Animals treated with PBMT exhibited significantly increased HIF-1α expression and ERK phosphorylation compared with animals that did not receive this treatment, and the amount of phospho-eNOS and iNOS increased and decreased, respectively. Conclusions: PBMT can induce therapeutic angiogenesis, indicating that low intensity laser could be a novel treatment for PAD patients.

Effect of Radial Extracorporeal Shock Wave Therapy on Pain Intensity, Functional Efficiency, and Postural Control Parameters in Patients with Chronic Low Back Pain: A Randomized Clinical Trial

Low back pain (LBP) is the leading cause of disability worldwide, placing a significant economic burden on healthcare systems. Radial extracorporeal shock wave therapy (rESWT) is useful in the rehabilitation of orthopedic diseases; however, there is still limited evidence for patients with LBP. The aim of this study was to assess the effect of rESWT on pain level, functional efficiency, and parameters of postural control in patients with LBP. Participants were randomized into group A (n = 20) treated with rESWT and group B (n = 20) treated with sham rESWT (placebo). Both groups received conventional physiotherapy, including core stability exercises. The following tests were performed: the Laitinen Pain Scale (LPS), the Roland–Morris Questionnaire (RMQ), the original Schober Test (OST), and a stabilometric platform for the assessment of postural sway, including total sway path (TSP). We found that the analgesic effect was higher after rESWT, especially in the follow-up’s (p < 0.05). Similar results were found for functional efficiency and range of motion (p < 0.05). The improved posture stability in placebo group B was not statistically significant (p > 0.05). The stabilometric parameters in group A were still gradually improved and statistically significant, even in follow-ups (p < 0.05). In conclusion, the rESWT had a significant effect on the reduction of pain and the improvement of functional condition compared to a conventional physiotherapy program. Also, rESWT with core stability exercises led to significant improvements in postural sway compared with conventional physiotherapy in patients with LBP.

The Beneficial Effects of High-Intensity Laser Therapy and Co-Interventions on Musculoskeletal Pain Management: A Systematic Review

Introduction: High-intensity laser therapy (HILT) has been used more recently in the therapeutic protocols of pain managements. Adding therapeutic interventions to laser therapy is usual in clinical practice. This study aimed to evaluate the efficacy of HILT and beneficial effects of adding cointerventions to HILT in musculoskeletal pain management. Methods: The following databases were searched up to August 2018: Medline, PubMed, EMBASE, Cochrane, Google Scholar, Springer and ISI. The keywords of pain, HILT, high power laser therapy, laser therapy, photobiomodulation, physical therapy and rehabilitation were searched. The quality of the articles was assessed using the PEDro scale. The primary measure was pain severity expected to be reported in all studies. Effect size was calculated as standardized mean differences divided by the standard deviation of either the treatment or other group. Results: Initially 52 potential studies were found. Eighteen of these studies were excluded based on title and abstract. The full text of 34 remaining articles was screened and 15 of the studies were excluded. All included studies had high quality (PEDro ≥7). Approximately, 94% of included articles (n=18) revealed positive effects of HILT on pain. The effect sizes for HILT and placebo/comparator groups were 0.9-9.11 and 0.21-11.22 respectively. Also, the differences of effect size between two groups were between 0.03 to 5.85. Conclusion: It is early to determine that HILT may be an effective non-invasive agent in the management of musculoskeletal pain, as few studies have shown its clinical efficacy. Adding related co-interventions to HILT may enhance the beneficial effects of laser therapy. The variability of the study methods and outcomes suggests that further long-term follow-up, randomized controlled clinical trials with appropriate methodological design are needed regarding the effectiveness of HILT on pain.

Management of Primary Injuries of the Medial Collateral Ligament of the Carpus in Two Horses

This case report describes the successful management of two horses with medial carpal collateral ligament injury. This is a rare cause of forelimb lameness and existing reports indicate a poor prognosis for return to athletic function with conservative management. Both horses were treated with a combination of box rest with controlled exercise and high-intensity laser therapy (HILT). Both horses returned to previous athletic function, one at Grand Prix level dressage and one at Novice level eventing. With appropriate management, the prognosis for carpal collateral ligament injury may be good. From this report, it is unclear whether a rehabilitation program including HILT offers improved prognosis compared with a rehabilitation program alone.