Efficacy of low-level laser therapy in patients with lower extremity tendinopathy or plantar fasciitis: systematic review and meta-analysis of randomised controlled trials.

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.

Pain and Disability of Conservatively Treated Distal Radius Fracture: A Triple-Blinded Randomized Placebo-Controlled Trial of Photobiomodulation Therapy.

Objective: Many patients with distal radius fracture (DRF) experience pain and disability after removal of the cast. The aim of this study was to investigate if photobiomodulation therapy (PBMT) applied after cast removal provides an add-on effect to a home-based exercise program in rehabilitation after DRF. Methods: In this triple-blinded placebo-controlled trial, 50 patients with conservatively treated DRF were randomized to receive either active PBMT or placebo PBMT after cast removal in addition to a home-based exercise therapy program. The outcome measures were the Patient-Rated Wrist and Hand Evaluation (PRWHE) questionnaire, night pain (NP), and consumption of analgesic medication (AM) and were evaluated after cast removal at 4 (baseline), 8, 12, and 26 weeks after injury. NP and AM were also evaluated 7 weeks after injury (end of active/placebo PBMT). Results: There was a significant between-group difference in PRWHE scores in favor of active PBMT 8, 12, and 26 weeks after DRF. NP and consumption of AM were significantly lower in the active PBMT group from 7 to 26 weeks. There was a minimum clinically important improvement between the groups in favor of active PBMT in total score at 12 weeks, in pain subscore at 8, 12, and 26 weeks, and in disability subscore at 8 and 12 weeks. Conclusions: PBMT is safe and has long-term positive effect on pain and disability in DRF patients, when applied in combination with a home-based rehabilitation exercise program. Clinical Trial registration number: NCT03014024.

Treatment of Distal Radius Fracture During Immobilization with an Orthopedic Cast: A Double-Blinded Randomized Controlled Trial of Photobiomodulation Therapy.

Objective: With distal radius fracture (DRF) many patients experience stiffness and pain after removal of the cast. The aim of this study was to investigate possible effects of photobiomodulation therapy (PBMT) in DRF during immobilization with semicircular orthopedic cast. Methods: In this double-blinded, placebo-controlled trial, 53 patients with DRF were randomized to receive nine treatments of either PBMT or placebo-PBMT. The fractures were irradiated through openings in the cast. Patient-Rated Wrist and Hand Evaluation (PRWHE) questionnaire and clinical outcomes were measured at baseline, 4, 8, 12, and 26 weeks after the trauma. Results: No significant differences were found for PRWHE scores, although PBMT was significantly superior to placebo regarding active range of motion [AROM; 95% (confidence interval) CI: -65.25° to -20.42° and -25.57° to -0.73°, respectively] and grip strength at week 4 (95% CI: -12.10 to -1.67 kg). Side-to-side differences between injured and noninjured wrists were significantly smaller in the PBMT group regarding grip and pinch strength at week 4 (95% CI: 0.89 to 8.87 kg and 0.55 to 3.79 kg, respectively). Significantly less patients in the PBMT group reported night pain at week 3. Conclusions: PBMT administered during the immobilization period of DRF had no effect on perceived pain and function measured through PRWHE. Night pain was significantly reduced after 3 weeks by PBMT. PBMT significantly improved pinch and grip strength and AROM, but these findings did not translate to the subjective experience of pain and function. Trial registration number: Clinical.trials.gov number NCT02749929. The study was approved by the Regional ethics committee (REK-Vest) in Norway (App. No: 2015/330). Informed consent was obtained from all patients.

Efficacy of low-level laser therapy on pain and disability in knee osteoarthritis: systematic review and meta-analysis of randomised placebo-controlled trials.

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.

Effects of photobiomodulation therapy on inflammatory mediators in patients with chronic non-specific low back pain: Protocol for a randomized placebo-controlled trial.

INTRODUCTION: Low back pain (LBP) is ranked as one of the most prevalent health conditions. It is likely that some inflammatory mediators could be associated with pain and disability in these patients. Photobiomodulation therapy (PBMT) is a non-pharmacological therapy often used in patients with LBP and one of the possible mechanisms of action of therapy is modulate inflammatory mediators. However, to date there are no studies that evaluated the effects of PBMT on the levels of inflammatory mediators in patients with LBP. The aim of this study is to evaluate the acute effects of PBMT on systemic levels of inflammatory mediators and pain intensity in patients with chronic non-specific low back pain. METHODS AND ANALYSIS: This is a prospectively registered, two-arm randomized placebo-controlled trial with blinded patients, assessors and therapists. Eighteen patients with chronic non-specific LBP will be randomized into 2 groups: placebo or active PBMT. The treatment will be provided in a single session. The primary outcome will be levels of prostaglandin E2 (PGE2). The secondary outcomes will be levels of necrosis factor alpha (TNF-α), interleukin 6 (IL-6) and pain intensity. Biochemical and clinical outcomes will be measured at baseline and 15 minutes after the single treatment session. DISCUSSION: Despite PBMT be used in musculoskeletal disorders such as LBP, to the best of our knowledge this is the first study that will investigate a possible biological mechanism behind the positive clinical effects of PBMT on non-specific chronic low back pain. ETHICS AND DISSEMINATION: The study was approved by the Regional Research Ethics Committee. The results will be disseminated through publication in peer-reviewed international journal and conferences. TRIAL REGISTRATION NUMBER: NCT03859505.

Comparison of Photobiomodulation and Anti-Inflammatory Drugs on Tissue Repair on Collagenase-Induced Achilles Tendon Inflammation in Rats.

BACKGROUND: Tendinopathy is characterized by pain, edema, and structural changes in tendon tissue. OBJECTIVE: In this animal study we decided to compare the short- and medium-term effects of low-level laser therapy (LLLT), dexamethasone, and diclofenac on inflammation and tendon tissue repair in collagenase-induced tendinitis. MATERIALS AND METHODS: Two hundred five female Wistar rats were randomly divided into five groups. Animals in the control group were given a saline injection and the experimental groups received a collagenase injection (100 µg/tendon) in the peritendinous Achilles and received no treatment, LLLT (3 J, 810 nm, 100 mW), diclofenac (1.1 mg/kg), or dexamethasone (0.02 mg/kg). Histological analyses were performed at 10 time points up to 60 days (n = 5/group each time point), and included an assessment of the severity of inflammation, collagen fiber content, and organization. RESULTS: Collagenase injection induced a severe inflammatory reaction with significant reduction in collagen content for 48 h, and disorientation of collagen fibers lasting between 14 and 21 days. Diclofenac and dexamethasone reduced inflammatory signs during the first 2 days, although there was prolongation of the inflammatory phase and slower normalization of tendon quality, particularly in the dexamethasone group. LLLT prevented hemorrhage, reduced inflammation severity, and preserved tendon morphology compared with the other groups. CONCLUSIONS: LLLT showed a significant superiority over commonly used anti-inflammatory pharmaceutical agents in acute collagenase-induced tendinitis.

Achilles Tendon Penetration for Continuous 810 nm and Superpulsed 904 nm Lasers Before and After Ice Application: An In Situ Study on Healthy Young Adults.

BACKGROUND AND OBJECTIVE: There is a lack of knowledge about the influence tissue temperature may have on laser light penetration and tendon structure. The purpose of this study was to investigate whether penetration of laser energy in human Achilles tendons differed before and after ice pack application. MATERIALS AND METHODS: The Achilles tendons (n = 54) from 27 healthy young adults were irradiated with two class 3B lasers (810 nm 200 mW continuous mode laser and a 904 nm 60 mW superpulsed mode laser). The optical energy penetrating the Achilles area was measured before and after 20 min of ice application. Measurements were obtained after 30, 60, and 120 sec irradiation with the 904 nm laser and after 30 and 60 sec irradiation with the 810 nm laser. Achilles tendon thickness was measured with ultrasonography. RESULTS: Optical energy penetration increased significantly (p < 0.01) after ice application for both lasers and at all time points from 0.34% to 0.39% of energy before ice application to 0.43-0.52% of energy after ice application for the 904 nm laser and from 0.24% to 0.25% of energy before ice application to 0.30-0.31% of energy after ice application for the 810 nm laser. The energy loss per centimeter of irradiated tissue was significantly higher (p < 0.05) at all time points after ice application. Ultrasonography imaging of skin-to-skin and transversal tendon thickness was significantly reduced after ice application at p = 0.05 and p = 0.03, respectively. Achilles tendon thickness in the longitudinal plane remained unchanged (p = 0.49). CONCLUSIONS: The penetration of laser light increased significantly through healthy Achilles tendons subjected to 20 min of cooling. These findings occurred in the presence of a significant reduction in skin temperature and Achilles tendon thickness.

Penetration Time Profiles for Two Class 3B Lasers in In Situ Human Achilles at Rest and Stretched.

BACKGROUND AND OBJECTIVE: The majority of studies investigating penetration of laser light are performed in vitro on skin flaps, with measures of immediate penetration depth and energy loss. The aim of this study was to investigate the penetration time profiles for two different lasers used in low-level laser therapy, during 150 sec of exposure both in stretched and relaxed human Achilles in situ. MATERIALS AND METHODS: Thirty-four Achilles tendons from 17 healthy volunteers were irradiated by an 810 nm, 200 mW, continuous- and a 904 nm, 60 mW, super-pulsed laser. Irradiation was performed with the Achilles tendons in relaxed and stretched condition. The energy penetrating skin-skin was measured every 30 sec using an optical power meter. RESULTS: The 810 nm laser penetration ability did not differ significantly in relaxed and stretched condition with 0.17% [standard error of the mean (SEM) 0.02] of mean output power (MOP) and 0.02% (SEM 0.004) of MOP, respectively. The 904 nm laser demonstrated a statistical significant (p < 0.05) and almost linear increasing penetration ability both in relaxed and stretched Achilles from 0.25% (SEM 0.03) to 0.38% (SEM 0.04) of MOP and from 0.05% (SEM 0.01) to 0.13% (SEM 0.01) of MOP, respectively. The penetrated ability differed between lasers and tissue conditions at all measure points (p < 0.05). CONCLUSIONS: The 904 nm laser penetrates relatively more energy than the 810 nm laser in in situ human Achilles. Moreover, penetration from the super-pulsed 904 nm laser increased during exposure time, whereas penetration from the 810 nm laser was constant. In addition, stretching the Achilles causes a higher energy attenuation by the tissue.

Low-Level Laser Therapy and Cryotherapy as Mono- and Adjunctive Therapies for Achilles Tendinopathy in Rats.

BACKGROUND AND OBJECTIVE: Low-level laser therapy (LLLT) and cryotherapy are widely used treatments in the acute phase of tendon injury. The aim of this study was to investigate the interaction of these two treatments on tendon inflammation and mechanical properties. MATERIALS AND METHODS: Six groups of six Wistar rats were used in this study. The Achilles tendons of the healthy control group were not subjected to injury or treatment. The tendons of the injured nontreated group (ING) were injured, but not treated. The remaining four groups were injured and subjected to LLLT, cryotherapy, LLLT first/cryotherapy, or cryotherapy first/LLLT. All treatments were performed at 1 h post-trauma. Inflammatory mediators, tendon histology, and biomechanical properties were assessed at 24 h post-trauma by comparing the treatment groups with the ING. RESULTS: In all treatment groups, the inflammatory process shifted in an anti-inflammatory direction compared with the ING. Significant alterations in cytokine expression were found in only the LLLT group (↓IL-1ß) and the combined intervention groups (↓IL-1ß, ↓TNF-α, ↑IL-6). It was also found that cryotherapy followed by LLLT was the only treatment that significantly (p < 0.05) improved the biomechanical parameters of force (N) and displacement (mm) at the tendon rupture and corresponded with the best histological scores of all of the treatment groups. CONCLUSIONS: Our results demonstrate that cryotherapy in combination with LLLT can produce an anti-inflammatory "add-on" effect. The order of therapy administration seems essential, as superior histology and biomechanical results were found in the cryotherapy first/LLLT group.