Effectiveness of an aquatic exercise program and low-level laser therapy on articular cartilage in an experimental model of osteoarthritis in rats

Effects of a low, medium, and high-intensity aquatic physiotherapy protocol on functional and biochemical parameters in individuals with knee osteoarthritis: protocol for a crossover randomized controlled trial

Background

Knee osteoarthritis affects the performance of daily activities, independence, and quality of life. The etiopathogenesis of this condition considers the mechanisms of activation of metalloproteinase and reactive oxygen species production pathways. Metalloproteinases-3 (MMP-3) and Glutathione Peroxidase (GPx) may be responsible for cartilage destruction. Aquatic physiotherapy promotes a positive impact on the clinical picture of osteoarthritis, and this study presents an intervention protocol that aims to evaluate the effects of a single session of different aquatic physiotherapy modalities on the biochemical and functional behavior of patients with knee osteoarthritis.

Methods

This will be a crossover randomized controlled trial in which 15 individuals will be submitted to three aquatic physiotherapy modalities with a minimum 15-day wash-out period in patients over 50 years old and diagnosed with OA in at least one knee, presence of pain and at least one functional dysfunction for at least 6 months, absence of physical limitation that prevents the exercise protocol from being performed, Kellgren and Lawrence ranking between I and IV, walk independently and without auxiliary device. Variations in the concentrations of MMP-3 and GPx in peripheral blood, pain, edema, and flexibility resulting from the three aquatic physiotherapeutic interventions will be evaluated both pre- and immediate post-intervention. The reference group will be submitted to the same aquatic physiotherapy protocols, however, only the biochemical parameters and the self-perception questionnaires will be evaluated.

Registration

ClinicalTrials.gov ( NCT05610696, 18/01/2023).

Therapeutic effects of combining curcumin and swimming in osteoarthritis using a rat model

Osteoarthritis (OA) is a common debilitating degenerative disease of the elderly. We aimed to study the therapeutic effects of combining curcumin and swimming in monosodium iodoacetate (MIA)-induced OA in a rat model. The rats were divided into 5 groups (n = 9). Group 1 received saline and served as a control group. Groups 2-5 were injected intra-articularly in the right knee with 100 μL MIA. One week later, groups 3 and 5 were started on daily swimming sessions that gradually increased to 20-mins per session, and for groups 4 and 5, oral curcumin was administered at a dose of 200 mg/kg for 4 weeks. The combination therapy (curcumin + swimming) showed the most effective results in alleviating pain and joint stiffness as well as improving histological and radiological osteoarthritis manifestations in the knee joints. The combination modality also reduced serum C-reactive protein and tissue cartilage oligomeric matrix protein levels. Mechanistically, rats received dual treatment exhibited restoration of miR-130a and HDAC3 expression. The dual treatment also upregulated PPAR-γ alongside downregulation of NF-κB and its inflammatory cytokine targets TNF-α and IL-1β. Additionally, there was downregulation of MMP1 and MMP13 in the treated rats. In conclusion, our data showed that there is a therapeutic potential for combining curcumin with swimming in OA, which is attributed, at least in part, to the modulation of miR-130a/HDAC3/PPAR-γ signaling axis.

Effect of low-level laser therapy plus exercise therapy on pain, range of motion, muscle strength, and function in knee osteoarthritis - a systematic review and meta-analysis

BACKGROUND

Knee osteoarthritis (KOA) is commonly associated with multiple musculoskeletal impairments.

OBJECTIVE

The purpose of this review was (1) to investigate the effectiveness of LLLT plus ET on pain, ROM, muscle strength, and function in KOA immediately after therapy and (2) whether the effectiveness of LLLT plus ET could be sustained at follow-up (4 - 32 weeks).

METHODS

Six databases were systematically searched upto December 2021 to find relevant articles. Included studies were RCTs written in English, which compared LLLT plus ET with placebo LLLT plus ET in KOA. Three independent reviewers extracted data and assessed the quality of included studies. Standard mean difference (SMD) was used in meta-analysis using random effect model.

RESULT

Of the 6307 articles, 14 RCTs (820 patients) met the inclusion criteria. The results demonstrated that there was a significant difference in pain immediately after therapy (SMD: -0.58, p = 0.001) and at follow-up (SMD: -1.35, p = 0.05) in LLLT plus ET group. There were no significant differences in knee ROM, muscle strength, and knee function outcomes immediately and at follow-up.

CONCLUSION

Our findings indicate that LLLT plus ET could be considered to alleviate pain in the KOA. LLLT reduces pain at 4-8J with a wavelength of 640-905nm per point applied for 10-16 sessions at a frequency of 2 sessions/week. An exercise therapy program at prescribed dosage involving major muscle groups might help. However, LLLT plus ET is no more effective than placebo LLLT plus ET in improving ROM, muscle strength, and function in KOA.

A randomized comparative study between high-intensity laser vs low-intensity pulsed ultrasound both combined with exercises for the treatment of knee osteoarthritis

OBJECTIVE

To compare the effects of high-intensity laser therapy (HILT) plus exercise therapy (ET) vs low-intensity pulsed ultrasound (LIPUS) plus ET in knee osteoarthritis (KOA).

METHODS

A single blinded randomized controlled trial in an outpatient setting. There were 60 participants with grades II and III KOA based on the radiological findings in Kellgren and Lawrence grading scale. Participants were allocated randomly into three groups, study group I (HILT+ET), study group II (LIPUS+ET), and control (ET) group. Participants in the three groups received active range of motion (ROM) exercises, muscle strengthening, and flexibility exercises. Treatment was administered 5 times/wk for two successive weeks. Primary outcomes involved visual analog scale (VAS), secondary outcomes involved knee ROM, proprioceptive accuracy and Western Ontario and McMaster Universities Arthritis Index scale. All outcomes were measured pre- and post-treatment.

RESULTS

The mean age of participants was 55.4 ± 6.34, 55.2 ± 4.77 and 57 ± 6.39 years in HILT+ET, LIPUS+ET and control group respectively. There were statistically significant time-by-group effects (mixed-design multivariate analysis of variance) on all measured outcomes for all groups (P < .0001). However, HILT+ET yielded better improvement than the other groups (P < .0001). Between-group comparison revealed a significant difference in all measured outcomes between study group 1 vs study group 2, and between each study group vs the control group (P = .0001).

CONCLUSION

The effect of HILT combined with exercises achieved better results in pain, knee ROM, proprioceptive accuracy and functional disability than LIPUS combined with exercises and both are better than exercises only.

Exercise for Osteoarthritis: A Literature Review of Pathology and Mechanism

Osteoarthritis (OA) has a very high incidence worldwide and has become a very common joint disease in the elderly. Currently, the treatment methods for OA include surgery, drug therapy, and exercise therapy. In recent years, the treatment of certain diseases by exercise has received increasing research and attention. Proper exercise can improve the physiological function of various organs of the body. At present, the treatment of OA is usually symptomatic. Limited methods are available for the treatment of OA according to its pathogenesis, and effective intervention has not been developed to slow down the progress of OA from the molecular level. Only by clarifying the mechanism of exercise treatment of OA and the influence of different exercise intensities on OA patients can we choose the appropriate exercise prescription to prevent and treat OA. This review mainly expounds the mechanism that exercise alleviates the pathological changes of OA by affecting the degradation of the ECM, apoptosis, inflammatory response, autophagy, and changes of ncRNA, and summarizes the effects of different exercise types on OA patients. Finally, it is found that different exercise types, exercise intensity, exercise time and exercise frequency have different effects on OA patients. At the same time, suitable exercise prescriptions are recommended for OA patients.

In Vitro and In Vivo Effects of Light Therapy on Cartilage Regeneration for Knee Osteoarthritis: A Systematic Review

OBJECTIVE

To analyze the effects of light therapy (LT) on cartilage repair for knee osteoarthritis (OA) treatment.

DESIGN

The PubMed, Embase, Scopus, and Web of Science databases were searched up to August 31, 2020 to identify in vitro and in vivo studies that analyzed the effects of LT on knee cartilage for OA treatment. The study and sample characteristics, LT intervention parameters and posttreatment outcomes were analyzed. Risk of bias was assessed using the Risk of Bias Assessment for Non-randomized Studies (RoBANS) tool.

RESULTS

Three in vitro and 30 in vivo studies were included. Most studies were judged as high risk of performance and detection bias. Biochemical outcomes were analyzed for both in vitro and in vivo studies, and histological and behavioral outcomes were analyzed for in vivo studies. LT reduced extracellular matrix (ECM) degradation, inflammation, and OA progression, promoting ECM synthesis. LT improved pain-like behavior in animal models, having no apparent effect on gait performance. There were conflicting findings of some of the biochemical, histological, and behavioral outcomes.

CONCLUSION

The included studies presented different strategies and LT parameters. LT resulted in positive effects on cartilage repair and may be an adequate therapy for OA treatment.

Photobiomodulation Therapy Partially Restores Cartilage Integrity and Reduces Chronic Pain Behavior in a Rat Model of Osteoarthritis: Involvement of Spinal Glial Modulation

OBJECTIVE

Chronic pain associated with osteoarthritis (OA) often leads to reduced function and engagement in activities of daily living. Current pharmacological treatments remain relatively ineffective. This study investigated the efficacy of photobiomodulation therapy (PBMT) on cartilage integrity and central pain biomarkers in adult male Wistar rats.

DESIGN

We evaluated the cartilage degradation and spinal cord sensitization using the monoiodoacetate (MIA) model of OA following 2 weeks of delayed PBMT treatment (i.e., 15 days post-MIA). Multiple behavioral tests and knee joint histology were used to assess deficits related to OA. Immunohistochemistry was performed to assess chronic pain sensitization in spinal cord dorsal horn regions. Furthermore, we analyzed the principal components related to pain-like behavior and cartilage integrity.

RESULTS

MIA induced chronic pain-like behavior with respective cartilage degradation. PBMT had no effects on overall locomotor activity, but positive effects on weight support (P = 0.001; effect size [ES] = 1.01) and mechanical allodynia (P = 0.032; ES = 0.51). Greater optical densitometry of PBMT-treated cartilage was evident in superficial layers (P = 0.020; ES = 1.34), likely reflecting the increase of proteoglycan and chondrocyte contents. In addition, PBMT effects were associated to decreased contribution of spinal glial cells to pain-like behavior (P = 0.001; ES = 0.38).

CONCLUSION

PBMT during the chronic phase of MIA-induced OA promoted cartilage recovery and reduced the progression or maintenance of spinal cord sensitization. Our data suggest a potential role of PBMT in reducing cartilage degradation and long-term central sensitization associated with chronic OA.

Does low level laser therapy has effects on inflammatory biomarkers IL-1β, IL-6, TNF-α, and MMP-13 in osteoarthritis of rat models-a systemic review and meta-analysis

Osteoarthritis (OA) is a chronic degenerative joint disease and is considered as the most common cause of pain and disability. To the best of our knowledge, it is generally observed that there is a lack of evidence on the effects of low-level laser therapy (LLLT) on inflammatory cytokines in OA. The present review aims to appraise the current evidence of efffects of LLLT on inflammatory cytokines in OA of the knee. Medical databases such as Medline, PubMed, EMBASE, PEDro CINAHL, Web of Science, Cochrane register, and Google reference were searched from its inception to June 2019. Articles that meet the inclusion criteria: subjects (animals-Wistar rats) induced with OA; rats with age group of 50-90 days; weight of 150-300 g; finding the effects of LLLT; reporting inflammatory cytokines; and articles written in English were included. The reviewers assessed the methodological quality of the primary studies. Data of inflammatory cytokines IL-1β, IL-6, TNF-α, and MMP-13 were extracted for analysis. The Q (x2) test and I2 statistics analysis were performed to find the heterogeneity evaluation. Standard mean difference (SMD) and its 95% confidence interval (CI) were used to synthesize the data. Two hundred eleven potential articles were identified and 186 articles were excluded based on the selection criteria. The rest of the 25 articles were read and 8 articles were selected for further study. From the study, it is observed that the laser therapy group had mild to moderate improvement than control group in IL-1β, TNF-α, and MMP-13 (IL-1β; SMD 1.21 [95% CI - 0.278, 2.704], TNF-α; SMD 5.19 [95% CI 2.413, 7.961], and MMP-13 SMD - 1.45 [95% CI - 5.121, 2.211]), while IL-6 [SMD 3.11 (95% CI 0.662, 5.549] did not show any considerable improvement after laser therapy. The present review provides the evidence of LLLT-dependent reduction of IL-1β, TNF-α, and MMP-13, and its ability to modulate proliferation of inflammatory cells, which makes LLLT a suitable treatment for OA. Though the included studies showed a high heterogeneity in treatment parameter, the beneficial effect of LLLT on changes in inflammatory cytokines, such as IL-6, seems to be unaffected.

Low-intensity photobiomodulation at 632.8 nm increases tgfβ3, col2a1, and sox9 gene expression in rat bone marrow mesenchymal stem cells in vitro

The high incidence of cartilage destructions, as well as the social and economic importance of this pathology attracted great interest to the problem. At the present time, some data are available about the 632.8 nm low-intensity laser photobiomodulation positive effect on the cartilage tissue proliferation. The effect of this wavelength laser irradiation on the mesenchimal stem cell (MSC) differentiation in the chondrogenic direction was studied. The main aim of this work was to assess the low-intensity photobiomodulation effect on chondrogenesis. In this experiment, the cell model was used to compare the photobiomodulation and cytokine Tgfβ3 (transforming growth factor β 3) effects. Bone marrow MSCs were isolated from Wistar rats and cultured for the third passage. Chondrogenic effects of low-intensity He-Ne laser photobiomodulation and cytokine Tgfβ3 (10 ng/μL) were analyzed and compared after 21 days. The radiation source was the standard LGN-208 helium-neon (He-Ne) laser (632.8 nm, 1.7 mWt). Irradiation was performed cyclically for 15 min with 45-min pauses. The increase of the responsible for chondrogenesis (col2a1, tgfβ3, and sox9) main gene expression under the photobiomodulation at 632.8 nm was evaluated in comparison with Tgfβ3 effect. The tgfβ3, col2a1, and sox9 gene expression increase was obtained in two experimental groups: using the laser photobiomodulation and cytokine Tgfβ3 effect. Gene expression levels of tgfβ3, col2a1, and sox9 were measured using real-time polymerase chain reaction (RT-PCR) according to the -ΔΔCt method. It was found that the responsible for chondrogenesis genes expression (tgfβ3, col2a1, sox9) increased under the action of specific laser photobiomodulation during the observation period (from 0 to 21 days). The chondrogenic differentiation effect under the laser irradiation is less significant than Tgfβ3 cytokine effect.

Photobiomodulation Therapy (Light-Emitting Diode 630 nm) Favored the Oxidative Stress and the Preservation of Articular Cartilage in an Induced Knee Osteoarthritis Model

Objective: To evaluate the effects of photobiomodulation (PBM) therapy on oxidative stress and histological aspects of knee osteoarthritis (OA) induced by sodium monoiodoacetate in Wistar rats. Background: OA is a chronic degenerative disease. In addition to the inflammatory role, other factors, such as redox balance, appear to contribute to changes in the articular cartilage, the main articular structure affected. PBM therapy using light-emitting diode (LED) has been proposed to treat the disease by favoring anti-inflammatory effects and modulating markers of oxidative stress, acting on the degenerative process of cartilage. Methods: Twenty-seven male rats were separated into three groups: control (CG), OA (OAG), and LED treatment (LEDG). In the LED group, PBM (LED 630 nm, 300 mW, 9 J/cm², 0.3 W/cm², 30 sec) was applied, starting 24 h after induction, three times per week, for 8 weeks. Cartilage thickness, number of chondrocytes, enzymatic antioxidant defenses [superoxide dismutase (SOD) and catalase (CAT)], oxidative damage [thiobarbituric acid reactive substances (TBARS)], and nonenzymatic defense (ferric reducing antioxidant power) were analyzed. Results: The LEDG had higher average cartilage thickness compared with the OAG and had similar thickness to the CG. Also, the number of chondrocytes was similar to the CG. In the oxidative stress analysis, the LEDG presented antioxidant enzymatic activity (SOD and CAT) higher than the CG, and presented concentration of TBARS lower than the CG and OAG groups. Conclusions: PBM therapy was effective in recovering oxidative stress and preserving the articular cartilage aspects in a knee OA animal model.

Photobiomodulation and Sida tuberculata combination declines the inflammation's markers in knee-induced osteoarthritis

The aim of this study was to assess potential combination effects of photobiomodulation therapy (PBMT) with Sida tuberculata extracts on the oxidative stress and antioxidant activity, as well as on the inflammatory process. Rats with knee osteoarthritis (OA) were treated with S. tuberculata extracts and PBMT (904 nm, 18 J/cm²). The animals were evaluated for nociception and edema. The blood, knee lavage and structures, spinal cord, and brainstem were collected for biochemical analyses (lipid peroxidation, protein carbonyl content, superoxide dismutase activity, non-protein thiol levels, and measurement of nitrite/nitrate). The knee structures were also used to measure cytokine levels. PBMT lowered the damage due to oxidative stress in the knee and at distant sites from the lesion. PBMT also reduced the levels of nitric oxide and cytokines, which could explain the nociception reduction mechanism. Similarly, S. tuberculata decreased the damage by oxidative stress, levels of nitrite/nitrate, and cytokines. The therapy combination reduced levels of cytokines and nitrite/nitrate. PBMT and S. tuberculata extracts reduced the oxidative stress and inflammation. It is noteworthy that PBMT increased the antioxidant activity in the knee and at sites distant from the lesion, contributing to a more significant decrease in nociception. The combination of therapies did not present significant effects on the analyzed parameters. Therefore, it is suggested that PBM is sufficient to minimize the signs and symptoms of the knee OA in our rat model.

Level of pain, muscle strength and posture: effects of PBM on an exercise program in women with knee osteoarthritis - a randomized controlled trial

To evaluate the effectiveness of an exercise program associated to photobiomodulation (PBM) on pain, postural changes, functionally, and muscular strength in women, one of the risk factors, with knee osteoarthritis (OA). A randomized controlled trial, with a blinded assessor and intention-to-treat analysis and placebo control. Sixty-two participants with knee OA (with confirmed radiological diagnosis) were evaluated for this study. However, 34 were considered eligible and were randomized into two groups: EPPG - exercise and PBM placebo group (n = 17) and EPAG - exercise and PBM active group (n = 16), but one participant was excluded of EPAG. The exercise program and PBM (808 nm, 100 mW/point, 4 J/point, 56 J total, 91 J/cm2) were realized twice a week, during 8 weeks. West Ontario and the McMaster University Osteoarthritis Index (WOMAC) and Lequesne questionnaires, 1-repetition maximum test (1-RM) and posture evaluation software (SAPO) were used to analyze the effects of the therapies. In intragroup analysis, a significant improvement in pain WOMAC (p < 0.001), stiffness (p < 0.001), function (p < 0.001), Lequesne (p < 0.001), and 1-RM (all muscle groups) (p < 0.001) were observed. In this study, the exercise program improved pain, function, and muscle strength of all the participants. However, PBM, in the parameters used, did not optimize the effects of the exercise program in women with knee OA.

Randomized controlled trial of aquatic exercise for treatment of knee osteoarthritis in elderly people

Aim

The aim of this study is to assess the efficacy of aquatic exercise on pain, gait, and balance among elderly patients with knee osteoarthritis.

Methods

We performed a randomized controlled trial at a university hospital. Overall, 32 men with knee osteoarthritis, aged ≥ 60 years, were included. Pain, balance, and gait were evaluated before and 2 months after interventions. The group control used acetaminophen and followed lifestyle recommendations. The intervention group performed the aquatic exercise three sessions per week for 8 weeks.

Results

At the end of the study, mean pain scores were significantly different between the groups (p = 0.010). Within-group analyses showed that group intervention experienced significant pain relief (p = 0.019), whereas group control did not show the significant change (p = 0.493). There was significant improvement in favor of aquatic exercise with regard to static (p = 0.001) and dynamic (p = 0.001) balance, step length (p = 0.038), stride length (p < 0.001), and cadence (p < 0.001). However, we did not find a significant difference in step time and width between the two groups.

Conclusions

Aquatic exercise would be beneficial in decreasing subjective pain of osteoarthritis. There are some recognizable improvements in patients’ gait and balance as well.

Low Level Laser Therapy in Knee Osteoarthritis: A Narrative Review

Knee osteoarthritis (KOA) is the most common musculoskeletal disorder, especially in middle up to old age. KOA also results in many complications like changes in gait. Nowadays, changes in lifestyle and the reduced physical activity make people more vulnerable to KOA. Therefore, considering the increasing prevalence of KOA in many societies and the costs imposed on the afflicted people and their governments, providing conservative management approaches with a view to saving time and money is important. There are an assortment of conservative strategies in the management of KOA including low level laser therapy (LLLT). Since the introduction of lasers in the medical field in 1960, various types of lasers with widespread administration programs are used for medical conditions from cosmetics to surgery. However, there are conflicting findings on the application of lasers in osteoarthritis. To discuss the basis of the highest level of evidence, only systematic reviews with or without meta-analyses published up to January 2019 were included in the present work. In this regard, Scopus, PEDro, Medline, ISI Web of Science, Cochrane, PubMed, Irandoc, Iran Medex, Magiran, and SID were searched to retrieve articles in English or Persian. A total of 22 systematic reviews and meta-analyses were found, 14 of which were included in this study. The accepted articles were published between 1991 and up to 2019. The purpose of this narrative review was to investigate the effect of LLLT on pain and function in subjects with KOA. The result of the present review may help clinicians in making evidence-based decisions on optimal care in relation to administering LLLT.

Resistance training decreases matrix metalloproteinase-2 activity in quadriceps tendon in a rat model of osteoarthritis

BACKGROUND

Osteoarthritis (OA) is a degenerative disease that induces peri-articular tissue degradation. OA induces an imbalance between synthesis and degradation of the extracellular matrix components in favor of catabolic events, promoting pathological remodeling and involving degradative enzymes, such as matrix metalloproteinases (MMPs).

OBJECTIVE

This study aimed to investigate the effects of 8-weeks resistance training (RT) on MMP-2 activity in the quadriceps tendon and patellar tendon in an OA model.

METHODS

Twenty-four Wistar rats were randomly divided into six groups: Control, Exercise, Sham, Sham with Exercise, OA, and OA with Exercise (OAE). The OA model was performed by anterior cruciate ligament transection surgery on the left knee. The 8-week RT consisted of climbing a 1.1-m vertical ladder three times per week with progressive weights secured to the animals' tails. MMP-2 activity was analyzed by zymography.

RESULTS

The OAE group displayed lower pro, intermediate, and active MMP-2 activity in the quadriceps tendon compared with the OA group (p<0.05). For the patellar tendon, there was no significant difference between the OAE group compared with the other groups (p>0.05) for pro, intermediate, and active MMP-2 activity. Moreover, MMP-2 activity differed between tissues, the OA and OAE groups presented lower pro, intermediate, and active MMP-2 activity in the quadriceps tendon compared to the patellar tendon.

CONCLUSION

RT induced down-regulated MMP-2 activity in the quadriceps tendon. RT is a potential therapeutic approach to minimize the deleterious effects of extracellular matrix degeneration.

Photobiomodulation therapy in knee osteoarthritis reduces oxidative stress and inflammatory cytokines in rats

Knee osteoarthritis (OA) is a chronic disease that causes pain and gradual degeneration of the articular cartilage. In this study, MIA-induced OA knee model was used in rats to test the effects of the photobiomodulation therapy (PBM). We analyzed the inflammatory process (pain and cytokine levels), and its influence on the oxidative stress and antioxidant capacity. Knee OA was induced by monosodium iodoacetate (MIA) intra-articular injection (1.5 mg/50 μL) and the rats were treated with eight sessions of PBM 3 days/week (904 nm, 6 or 18 J/cm² ). For each animal, mechanical and cold hyperalgesia and spontaneous pain were evaluated; biological analyses were performed in blood serum, intra-articular lavage, knee structures, spinal cord and brainstem. Cytokine assays were performed in knee, spinal cord and brainstem samples. The effects of the 18 J/cm² dose of PBM were promising in reducing pain and neutrophil activity in knee samples, together with reducing oxidative stress damage in blood serum and spinal cord samples. PBM improved the antioxidant capacity in blood serum and brainstem, and decreased the knee pro-inflammatory cytokine levels. Our study demonstrated that PBM decreased oxidative damage, inflammation and pain. Therefore, this therapy could be an important tool in the treatment of knee OA.

Photobiomodulation via a cluster device associated with a physical exercise program in the level of pain and muscle strength in middle-aged and older women with knee osteoarthritis: a randomized placebo-controlled trial

Osteoarthritis (OA) is a chronic joint disease that leads to pain and functional incapacity. The aim of the study is to investigate the effects of the incorporation of photobiomodulation (PBM) (via cluster) into a physical exercise program on the level of pain, lower limb muscle strength, and physical capacity, in patients with knee OA. Sixty-two female volunteers with a diagnosis of knee OA were distributed in 4 groups: exercise associated with placebo PBM group, exercise associated with active PBM group, active PBM group, and placebo PBM group. Sixteen sessions of lower limb strength exercises and PBM via cluster (808 nm, 100 mW, 7 points each side, 56 J total) were performed. The level of pain, physical capacity, and lower limb muscle strength were evaluated with the use of the numeric pain rating scale (NPRS), 6-min walking test (6-MWT) and timed up and go (TUG), and maximal voluntary isometric torque (MVIT) before and after the interventions. Both groups presented a significant decrease in the level of pain when compared with the placebo-treated women. Furthermore, the 6-MWT showed that the trained groups (with or without PBM) demonstrated higher values in the distance walked comparing pre and post-treatment values. The same behavior was found for the MVIT load before and after intervention. TUG was higher for all the treated with exercise groups comparing the pre and post-treatment values. Physical exercise and PBM showed analgesic effects. However, PBM did not have any extra effect along with the effects of exercise in improving the distance walked, the TUG, and the muscle strength.Trial registration: RBR-7t6nzr.

Isolated and combined effects of photobiomodulation therapy, topical nonsteroidal anti-inflammatory drugs, and physical activity in the treatment of osteoarthritis induced by papain

Osteoarthritis (OA) is a chronic inflammatory disease and is characterized as a degenerative process. This study aimed to evaluate and compare the effects of a topical nonsteroidal anti-inflammatory drug (NSAID), physical activity, and photobiomodulation therapy (PBMT) applied alone and/or in combination between them in an experimental model of knee OA. OA was induced by injection of papain in the knees of rats. After 21 days, the animals started to be treated with the above treatment. Histological analysis shows that the experimental model of OA induction causes morphological changes consistent with the disease, and among treatments, the PBMT is the most effective for reducing these changes. Moreover, the results demonstrate that PBMT and NSAID reduce the total number of cells in the inflammatory infiltrate (p<0.05) and PBMT was the most effective for reducing the activity of myeloperoxidase (p<0.05). Finally, we observed that both NSAID and PBMT were effective for reducing the gene expression of MMP-3 (p<0.05), but in relation to the gene expression of MMP-13, PBMT was the most effective treatment (p<0.05). The results of this study indicate that PBMT is the most effective therapy in stopping disease progression, and improving inflammatory conditions observed in OA.