Pulsed Red and Blue Photobiomodulation for the Treatment of Thigh Contusions and Soft Tissue Injury: A Randomized Controlled Trial.

CONTEXT: Contusion and soft tissue injuries are common in sports. Photobiomodultion, light and laser therapy, is an effective aid to increase healing rates and improve function after various injury mechanisms. However, it is unclear how well photobiomodulation improves function after a contusion soft tissue injury. This study aimed to determine the effects of a pulsed red and blue photobiomodulation light patch on muscle function following a human thigh contusion injury. DESIGN: Single-blinded randomized control trial design. METHODS: We enrolled 46 healthy participants. Participants completed 5 visits on consecutive days. On the first visit, participants completed a baseline isokinetic quadriceps strength testing protocol at 60°/s and 180°/s. On the second visit, participants were struck in the rectus femoris of the anterior thigh with a tennis ball from a serving machine. Immediately following, participants were treated for 30 minutes with an active or placebo photobiomodulation patch (CareWear light patch system, CareWear Corp). Following the treatment, participants completed the same isokinetic quadriceps strength testing protocol. Participants completed the treatment and isokinetic quadriceps strength test during the following daily visits. We normalized the data by calculating the percent change from baseline. We used a mixed model analysis of covariance, with sex as a covariate, to determine the difference between treatment groups throughout the acute recovery process. RESULTS: We found the active photobiomodulation treatment significantly increased over the placebo group, quadriceps peak torque during the 180°/s test (P = .030), and average power during both the 60°/s (P = .041) and 180°/s (P ≤ .001) assessments. The mean peak torque and average power of 180°/s, at day 4, exceeded the baseline levels by 8.9% and 16.8%, respectively. CONCLUSIONS: The red and blue photobiomodulation light patch improved muscle strength and power during the acute healing phase of a human thigh contusion injury model.

Effects of multiwavelength photobiomodulation for the treatment of traumatic soft tissue injuries associated with bone fractures: A double-blind, randomized controlled clinical trial.

This study evaluated the efficacy and safety of multiwavelength photobiomodulation (MPBM) in healing soft tissue injuries associated with tibial and/or ankle fractures. Participants were randomized into the MPBM or control group. Primary outcome was wound healing, measured by the Bates-Jensen scale. Assessments were performed daily. Twenty-seven hospitalized adults were included. MPBM showed an improvement in the daily mean Bates-Jensen scale (MPBM 32.1 vs. control 34.2; p = 0.029), daily mean pain score change (MPBM 0.5 vs. control 0.2; p = 0.04) and occurrence of infection at the site of the external fixator pins (MPBM 15.3% vs. control 57.1%; p = 0.02). MPBM group also showed faster-wound resolution (MPBM 13.1 vs. control 23.1 days). Subgroup analysis showed improvement in the MPBM group among less severe patients on the Bates-Jensen scale (MPBM 27.4 vs. control 34.7; p = 0.0081) and mean time for wound resolution (MPBM 7.0 vs. control 14.6 days; p = 0.03). MPBM appears safe and effective in reducing wound resolution time, infection in the surgical pin sites, reported pain and time before definitive surgery.

Carbon Arc Lamp Therapy Enhances the Repair Potential of Chronic Soft Tissue Injury in Rats Compared with the Ability of Photobiomodulation Therapy.

Objective: The effects of photobiomodulation therapy (PBMT) and carbon arc lamp therapy (CALT) on the repair of chronic soft tissue injury were compared. Background data: PBMT improves soft tissue repair of chronic injury. However, there has been no research on the effect of CALT. Methods: Human umbilical vein endothelial cells (HUVECs) were irradiated using PBMT and CALT at 2 J/cm2 to observe their effects on cell proliferation and migration. The effects of PBMT and CALT on soft tissue injury repair were assessed using a chronic gastrocnemius injury model of the posterior limb in rats. The malondialdehyde (MDA), superoxide dismutase (SOD), and prostaglandin E2 (PGE2) were examined by biochemical analyses. The degree of tissue damage repair was evaluated by the immunohistochemical method [CD45, CD34, vascular endothelial growth factor (VEGF), and actin] and the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method. Results: Treatment by PBMT and CALT significantly accelerated the proliferation and migration of HUVECs. Moreover, significant decreases in the contents of MDA and PGE2 were observed in the PBMT and CALT groups, while SOD activity was increased. The histological assessment shows that the content of inflammatory cells and apoptotic cells significantly decreased in the CALT group. However, the microvascular density, VEGF content, and actin content were increased in the CALT group. Conclusions: The results demonstrate that CALT has a stronger effect on promoting chronic soft tissue injury repair in comparison with PBMT.

Effects of Carbon Arc Lamp Irradiation on Wound Healing in a Rat Cutaneous Full-Thickness Wound Model.

Objective: The objective of the present study was to investigate the application of a carbon arc lamp on wound healing in a rat cutaneous full-thickness wound model. Background data: In clinical practice, wound healing has been promoted by irradiation with a carbon arc lamp. However, the corresponding mechanism has not been clearly defined. Methods: A cutaneous full-thickness wound on the back of rats was irradiated using a carbon arc lamp at a wavelength peak range of 620-740 nm with 54 J/cm2. Injured sham-irradiated control rats were used as the control. The rats were euthanized after 7, 14, and 21 days, while wound reepithelialization and healing quality were examined by histological analyses with comparison between groups. Cell proliferation was observed by 5-bromo-2'-deoxyuridine (BrdU) immunohistochemical staining. Results: Irradiation by the carbon arc lamp significantly accelerated wound healing. The wound-healing rate in the treated group at day 21 was 98.42% ± 0.56%, compared with 93.58% ± 1.26% in the control group (p < 0.05). Significant increases in the length of epithelial edges, collagen content, and microvessel density were observed in the wound sites in the treated group at days 7, 14, and 21 (p < 0.05). Moreover, the number of BrdU-labeled cells increased in the wound edge at days 7 and 14 due to irradiation (p < 0.05). Conclusions: The results demonstrated that the carbon arc lamp can promote wound healing together with improvement in its quality by stimulating cell proliferation.

Effects of low-level laser therapy (LLLT) and diclofenac (topical and intramuscular) as single and combined therapy in experimental model of controlled muscle strain in rats.

Muscle injuries represent ca 30% of sports injuries and excessive stretching of muscle causes more than 90% of injuries. Currently the most used treatments are nonsteroidal anti-inflammatory drugs (NSAIDs), however, in last years, low-level laser therapy (LLLT) is becoming an interesting therapeutic modality. The aim of this study was to evaluate the effect of single and combined therapies (LLLT, topical application of diclofenac and intramuscular diclofenac) on functional and biochemical aspects in an experimental model of controlled muscle strain in rats. Muscle strain was induced by overloading tibialis anterior muscle of rats. Injured groups received either no treatment, or a single treatment with topical or intramuscular diclofenac (TD and ID), or LLLT (3 J, 810 nm, 100 mW) 1 h after injury. Walking track analysis was the functional outcome and biochemical analyses included mRNA expression of COX-1 and COX-2 and blood levels of prostaglandin E2 (PGE2 ). All treatments significantly decreased COX-1 and COX-2 gene expression compared with injury group (P < 0.05). However, LLLT showed better effects than TD and ID regarding PGE2 levels and walking track analysis (P < 0.05). We can conclude that LLLT has more efficacy than topical and intramuscular diclofenac in treatment of muscle strain injury in acute stage.

Low-level laser therapy and sodium diclofenac in acute inflammatory response induced by skeletal muscle trauma: effects in muscle morphology and mRNA gene expression of inflammatory markers.

Pharmacological therapy is widely used in the treatment of muscle injuries. On the other hand, low-level laser therapy (LLLT) arises as a promising nonpharmacological treatment. The aim of this study was to analyze the effects of sodium diclofenac (topical application) and LLLT on morphological aspects and gene expression of biochemical inflammatory markers. We performed a single trauma in tibialis anterior muscle of rats. After 1 h, animals were treated with sodium diclofenac (11.6 mg g(-1) of solution) or LLLT (810 nm; continuous mode; 100 mW; 3.57 W cm(-2) ; 1, 3 or 9 J; 10, 30 or 90 s). Histological analysis and quantification of gene expression (real-time polymerase chain reaction-RT-PCR) of cyclooxygenase 1 and 2 (COX-1 and COX-2) and tumor necrosis factor-alpha (TNF-α) were performed at 6, 12 and 24 h after trauma. LLLT with all doses improved morphological aspects of muscle tissue, showing better results than injury and diclofenac groups. All LLLT doses also decreased (P < 0.05) COX-2 compared to injury group at all time points, and to diclofenac group at 24 h after trauma. In addition, LLLT decreased (P < 0.05) TNF-α compared both to injury and diclofenac groups at all time points. LLLT mainly with dose of 9 J is better than topical application of diclofenac in acute inflammation after muscle trauma.

Effects of low-level laser therapy (GaAs) in an animal model of muscular damage induced by trauma.

It has been demonstrated that reactive oxygen species (ROS) formation and oxidative damage markers are increased after muscle damage. Recent studies have demonstrated that low-level laser therapy (LLLT) modulates many biochemical processes mainly those related to reduction of muscular injures, increment of mitochondrial respiration and ATP synthesis, as well as acceleration of the healing process. The objective of the present investigation was to verify the influence of LLLT in some parameters of muscular injury, oxidative damage, antioxidant activity, and synthesis of collagen after traumatic muscular injury. Adult male Wistar rats were divided randomly into three groups (n = 6), namely, sham (uninjured muscle), muscle injury without treatment, and muscle injury with LLLT (GaAs, 904 nm). Each treated point received 5 J/cm(2) or 0.5 J of energy density (12.5 s) and 2.5 J per treatment (five regions). LLLT was administered 2, 12, 24, 48, 72, 96, and 120 h after muscle trauma. The serum creatine kinase activity was used as an index of skeletal muscle injury. Superoxide anion, thiobarbituric acid reactive substance (TBARS) measurement, and superoxide dismutase (SOD) activity were used as indicators of oxidative stress. In order to assess the synthesis of collagen, levels of hydroxyproline were measured. Our results have shown that the model of traumatic injury induces a significant increase in serum creatine kinase activity, hydroxyproline content, superoxide anion production, TBARS level, and activity of SOD compared to control. LLLT accelerated the muscular healing by significantly decreasing superoxide anion production, TBARS levels, the activity of SOD, and hydroxyproline content. The data strongly indicate that increased ROS production and augmented collagen synthesis are elicited by traumatic muscular injury, effects that were significantly decreased by LLLT.

Low-level laser therapy (808 nm) reduces inflammatory response and oxidative stress in rat tibialis anterior muscle after cryolesion.

BACKGROUND AND OBJECTIVE: Muscle regeneration is a complex phenomenon, involving coordinated activation of several cellular responses. During this process, oxidative stress and consequent tissue damage occur with a severity that may depend on the intensity and duration of the inflammatory response. Among the therapeutic approaches to attenuate inflammation and increase tissue repair, low-level laser therapy (LLLT) may be a safe and effective clinical procedure. The aim of this study was to evaluate the effects of LLLT on oxidative/nitrative stress and inflammatory mediators produced during a cryolesion of the tibialis anterior (TA) muscle in rats. MATERIAL AND METHODS: Sixty Wistar rats were randomly divided into three groups (n = 20): control (BC), injured TA muscle without LLLT (IC), injured TA muscle submitted to LLLT (IRI). The injured region was irradiated daily for 4 consecutive days, starting immediately after the lesion using a AlGaAs laser (continuous wave, 808 nm, tip area of 0.00785 cm(2) , power 30 mW, application time 47 seconds, fluence 180 J/cm(2) ; 3.8 mW/cm(2) ; and total energy 1.4 J). The animals were sacrificed on the fourth day after injury. RESULTS: LLLT reduced oxidative and nitrative stress in injured muscle, decreased lipid peroxidation, nitrotyrosine formation and NO production, probably due to reduction in iNOS protein expression. Moreover, LLLT increased SOD gene expression, and decreased the inflammatory response as measured by gene expression of NF-kß and COX-2 and by TNF-α and IL-1ß concentration. CONCLUSION: These results suggest that LLLT could be an effective therapeutic approach to modulate oxidative and nitrative stress and to reduce inflammation in injured muscle.

Low intensity laser therapy speeds wound healing in hemophilia by enhancing platelet procoagulant activity.

Our group has previously shown that cutaneous wound healing is delayed and histologically abnormal in a mouse model of hemophilia. Hemostasis is not only required to stop bleeding at the time of wounding, but also produces bioactive substances that promote appropriate inflammatory and proliferative responses during healing. Low intensity laser therapy (LILT) has been reported to enhance impaired wound healing in a variety of animal and human studies. The current studies were conducted to test the hypothesis that LILT can improve healing in a hemophilia B mouse model. Three daily treatments with 12 J/sq cm of 650 nm laser illumination reduced the time to closure of a 3-mm cutaneous punch biopsy wound in the hemophilic mice. All wounds were closed at 13 days in the sham-treated hemophilic mice, compared with 10 days in the LILT-treated hemophilic mice, and 9 days in wild-type mice. While LILT can speed healing by enhancing proliferation of cutaneous cells, we found that an additional mechanism likely contributes to the efficacy of LILT in the hemophilic mice. LILT enhanced the mechanical rigidity and platelet activity of clots formed from human platelet-rich plasma. Illumination of isolated platelets increased the mitochondrial membrane potential and enhanced binding of coagulation factors to the surface of activated platelets. Thus, while LILT can directly promote proliferative responses during healing, it also appears to enhance hemostasis in an animal model with impaired coagulation. These data suggest that trials of LILT as an adjunct to the usual hemostatic therapies in hemophilia are warranted.

[Effect of intravascular low level laser irradiation used in avulsion injury].

OBJECTIVE: To explore the effect of intravascular low level He-Ne laser irradiation on skin flap survival after orthotopic transplantation in avulsion injury. METHODS: Fifty eight cases suffered avulsion injury were treated by debridement and orthotopic transplantation of avulsed flap within 6 hours, 31 of them were received intravascular low level He-Ne laser irradiation and routine treatment, and 27 of them were received routine treatment as control group. RESULTS: The survival area and quality of avulsed flap in the experimental group were superior to that of control group after 15 days of operation, and the hemorheological items were markedly changed at 5 days after operation. CONCLUSION: The better flap survival after orthotopic transplantation in avulsion injury can be improved by intravascular low level He-Ne laser irradiation through changed superoxide dismutase activity and hemorheological items in optimal irradiation intensity.

Low intensity laser therapy: still not an established clinical tool.

The surgical, ophthalmological, and dermatological applications of high power lasers are well known and easily understood. What is neither as well known nor as easily understood is that lasers at powers that are orders of magnitude smaller have also been used in the laboratory and clinic for nearly 30 years to modulate cell function, lessen pain, and accelerate healing of soft tissue injuries. This article analyzes the rationale of this approach, examines the utility of laser therapy in its most common clinical applications, reviews and synthesizes the findings, and concludes that although laboratory findings seem authentic, clinical utility remains unestablished.