Objectives Low-level laser therapy (LLLT) is not recommended in major knee osteoarthritis (KOA) treatment guidelines. We investigated whether a LLLT dose–response relationship exists in KOA. Design Systematic review and meta-analysis. Data sources Eligible articles were identified through PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature, Physiotherapy Evidence Database and Cochrane Central Register of Controlled Trials on 18 February 2019, reference lists, a book, citations and experts in the field. Eligibility criteria for selecting studies We solely included randomised placebo-controlled trials involving participants with KOA according to the American College of Rheumatology and/or Kellgren/Lawrence criteria, in which LLLT was applied to participants’ knee(s). There were no language restrictions. Data extraction and synthesis The included trials were synthesised with random effects meta-analyses and subgrouped by dose using the World Association for Laser Therapy treatment recommendations. Cochrane’s risk-of-bias tool was used. Results 22 trials (n=1063) were meta-analysed. Risk of bias was insignificant. Overall, pain was significantly reduced by LLLT compared with placebo at the end of therapy (14.23 mm Visual Analogue Scale (VAS; 95% CI 7.31 to 21.14)) and during follow-ups 1–12 weeks later (15.92 mm VAS (95% CI 6.47 to 25.37)). The subgroup analysis revealed that pain was significantly reduced by the recommended LLLT doses compared with placebo at the end of therapy (18.71 mm (95% CI 9.42 to 27.99)) and during follow-ups 2–12 weeks after the end of therapy (23.23 mm VAS (95% CI 10.60 to 35.86)). The pain reduction from the recommended LLLT doses peaked during follow-ups 2–4 weeks after the end of therapy (31.87 mm VAS significantly beyond placebo (95% CI 18.18 to 45.56)). Disability was also statistically significantly reduced by LLLT. No adverse events were reported. Conclusion LLLT reduces pain and disability in KOA at 4–8 J with 785–860 nm wavelength and at 1–3 J with 904 nm wavelength per treatment spot. PROSPERO registration number CRD42016035587.

Objectives We investigated the effectiveness of low-level laser therapy (LLLT) in lower extremity tendinopathy and plantar fasciitis on patient-reported pain and disability. Design Systematic review and meta-analysis. Data sources Eligible articles in any language were identified through PubMed, Embase and Physiotherapy Evidence Database (PEDro) on the 20 August 2020, references, citations and experts. Eligibility criteria for selection of studies Only randomised controlled trials involving participants with lower extremity tendinopathy or plantar fasciitis treated with LLLT were included. Data extraction and synthesis Random effects meta-analyses with dose subgroups based on the World Association for Laser Therapy treatment recommendations were conducted. Risk of bias was assessed with the PEDro scale. Results LLLT was compared with placebo (10 trials), other interventions (5 trials) and as an add-on intervention (3 trials). The study quality was moderate to high. Overall, pain was significantly reduced by LLLT at completed therapy (13.15 mm Visual Analogue Scale (VAS; 95% CI 7.82 to 18.48)) and 4–12 weeks later (12.56 mm VAS (95% CI 5.69 to 19.42)). Overall, disability was significantly reduced by LLLT at completed therapy (Standardised Mean Difference (SMD)=0.39 (95% CI 0.09 to 0.7) and 4–9 weeks later (SMD=0.32 (95% CI 0.05 to 0.59)). Compared with placebo control, the recommended doses significantly reduced pain at completed therapy (14.98 mm VAS (95% CI 3.74 to 26.22)) and 4–8 weeks later (14.00 mm VAS (95% CI 2.81 to 25.19)). The recommended doses significantly reduced pain as an add-on to exercise therapy versus exercise therapy alone at completed therapy (18.15 mm VAS (95% CI 10.55 to 25.76)) and 4–9 weeks later (15.90 mm VAS (95% CI 2.3 to 29.51)). No adverse events were reported. Conclusion LLLT significantly reduces pain and disability in lower extremity tendinopathy and plantar fasciitis in the short and medium term. Long-term data were not available. Some uncertainty about the effect size remains due to wide CIs and lack of large trials. PROSPERO registration number CRD42017077511.

To assess the long-term effects of low-level laser therapy (LLLT), in combination with strengthening exercises in patients with osteoarthritis of the knee. Follow-up results at three and six months in a previously published randomized, double-blind, placebo-controlled trial. Specialist Rehabilitation Services. Forty participants of both genders, aged 50–75 years with knee osteoarthritis grade 2–4 on Kellgren–Lawrence scale. 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. 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. 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. We find that the immediate post-intervention improvements from LLLT plus strengthening exercises were maintained for six months.

Synovitis and effusion can cause pain sensitization in persons with knee osteoarthritis (KOA). Pain Pressure Threshold (PPT) algometry is a means to quantify somatosensory abnormalities, including ...

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.

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.