***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVE To assess the efficiency of a treatment composed of muscle stretching exercises , associated or not to laser therapy at tender points , for patients with fibromyalgia ( FM ) , in view of bettering their quality of life . METHODS Twenty FM patients were r and omly assigned to two groups : one su bmi tted to laser therapy and stretching ( LSG , n=10 ) , and the other only to stretching exercises ( SG , n=10 ) . The visual analog scale of pain ( VAS ) and dolorimetry at tender points were used to assess pain ; life quality was evaluated by means of the Fibromyalgia Impact Question naire ( FIQ ) and the 36-item Short-Form Health Survey ( SF-36 ) . RESULTS After the treatment program , both in LSG and SG were detected pain reduction , higher pain threshold at tender points ( all p<0.01 ) , lower mean FIQ scores , and higher SF-36 mean scores ( all p<0.05 ) . No significant differences were found between both groups . CONCLUSION The stretching exercises program proposed is efficient to reduce pain and painful sensibility at tender points , thus enhancing patients ' quality of life .  Laser therapy has not shown advantages when added to muscle stretching exercises BACKGROUND Previous research has suggested that tai chi offers a therapeutic benefit in patients with fibromyalgia . METHODS We conducted a single-blind , r and omized trial of classic Yang-style tai chi as compared with a control intervention consisting of wellness education and stretching for the treatment of fibromyalgia ( defined by American College of Rheumatology 1990 criteria ) . Sessions lasted 60 minutes each and took place twice a week for 12 weeks for each of the study groups . The primary end point was a change in the Fibromyalgia Impact Question naire ( FIQ ) score ( ranging from 0 to 100 , with higher scores indicating more severe symptoms ) at the end of 12 weeks . Secondary end points included summary scores on the physical and mental components of the Medical Outcomes Study 36-Item Short-Form Health Survey ( SF-36 ) . All assessment s were repeated at 24 weeks to test the durability of the response . RESULTS Of the 66 r and omly assigned patients , the 33 in the tai chi group had clinical ly important improvements in the FIQ total score and quality of life . Mean ( + /-SD ) baseline and 12-week FIQ scores for the tai chi group were 62.9+/-15.5 and 35.1+/-18.8 , respectively , versus 68.0+/-11 and 58.6+/-17.6 , respectively , for the control group ( change from baseline in the tai chi group vs. change from baseline in the control group , -18.4 points ; P<0.001 ) . The corresponding SF-36 physical-component scores were 28.5+/-8.4 and 37.0+/-10.5 for the tai chi group versus 28.0+/-7.8 and 29.4+/-7.4 for the control group ( between-group difference , 7.1 points ; P=0.001 ) , and the mental-component scores were 42.6+/-12.2 and 50.3+/-10.2 for the tai chi group versus 37.8+/-10.5 and 39.4+/-11.9 for the control group ( between-group difference , 6.1 points ; P=0.03 ) . Improvements were maintained at 24 weeks ( between-group difference in the FIQ score , -18.3 points ; P<0.001 ) . No adverse events were observed . CONCLUSIONS Tai chi may be a useful treatment for  fibromyalgia  and merits long-term study in larger study population s. ( Funded by the National Center for Complementary and Alternative Medicine and others ; Clinical Trials.gov number , NCT00515008 . Abstract . The purpose of this study was to examine the effectiveness of low power laser ( LPL ) and low-dose amitriptyline therapy and to investigate effects of these therapy modalities on clinical symptoms and quality of life ( QOL ) in patients with fibromyalgia ( FM ) . Seventy-five patients with FM were r and omly allocated to active gallium-arsenide ( Ga-As ) laser ( 25 patients ) , placebo laser ( 25 patients ) , and amitriptyline therapy ( 25 patients ) . All groups were evaluated for the improvement in pain , number of tender points , skin fold tenderness , morning stiffness , sleep disturbance , muscular spasm , and fatigue . Depression was evaluated by a psychiatrist according to the Hamilton Depression Rate Scale and DSM IV criteria . Quality of life of the FM patients was assessed according to the Fibromyalgia Impact Question naire ( FIQ ) . In the laser group , patients were treated for 3 min at each tender point daily for 2 weeks , except weekends , at each point with approximately 2 J/cm2 using a Ga-As laser . The same unit was used for the placebo treatment , for which no laser beam was emitted . Patients in the amitriptyline group took 10 mg daily at bedtime throughout the 8 weeks . Significant improvements were indicated in all clinical parameters in the laser group ( P=0.001 ) and significant improvements were indicated in all clinical parameters except fatigue in the amitriptyline group ( P=0.000 ) , whereas significant improvements were indicated in pain ( P=0.000 ) , tender point number ( P=0.001 ) , muscle spasm ( P=0.000 ) , morning stiffness ( P=0.002 ) , and FIQ score ( P=0.042 ) in the placebo group . A significant difference was observed in clinical parameters such as pain intensity ( P=0.000 ) and fatigue ( P=0.000 ) in favor of the laser group over the other groups , and a significant difference was observed in morning stiffness ( P=0.001 ) , FIQ ( P=0.003 ) , and depression score ( P=0.000 ) after therapy . A significant difference was observed in morning stiffness ( P=0.001 ) , FIQ ( P=0.003 ) , and depression ( P=0.000 ) in the amitriptyline group compared to the placebo group after therapy . Additionally , a significant difference was observed in depression score ( P=0.000 ) in the amitriptyline group in comparison to the laser group after therapy . Our study suggests that both amitriptyline and laser therapies are effective on clinical symptoms and QOL in fibromyalgia and that Ga-As laser therapy is a safe and effective treatment in cases with FM . Additionally , the present study suggests that the Ga-As laser therapy can be used as a monotherapy or as a supplementary treatment to other therapeutic procedures in FM The purpose of this study was to compare the effectiveness of low-level laser therapy ( LLLT ) on pain and functional capacity in patients with acute and chronic low back pain caused by lumbar disk herniation ( LDH ) .  LLLT has been used to treat acute and chronic pain of musculoskeletal system disorders . This study is a r and omized , double-blind , placebo-controlled study . Forty patients with acute ( 26 females/14 males ) and 40 patients with chronic ( 20 females/20 males ) low back pain caused by LDH were included in the study . Patients were r and omly allocated into four groups . Group 1 ( acute LDH , n = 20 ) received hot-pack + laser therapy ; group 2 ( chronic LDH , n = 20 ) received hot-pack + laser therapy ; group 3 ( acute LDH , n = 20 ) received hot-pack + placebo laser therapy , and group 4 ( chronic LDH , n = 20 ) received hot-pack + placebo laser therapy , for 15 sessions during 3 weeks . Assessment parameters included pain , patients ' global assessment , physician 's global assessment , and functional capacity . Pain was evaluated by visual analog scale ( VAS ) and Likert scale . Patients ' and physician 's global assessment were also measured with VAS . Modified Schober test and flexion and lateral flexion measures were used in the evaluation of range of motion ( ROM ) of lumbar spine . Rol and Disability Question naire ( RDQ ) and Modified Oswestry Disability Question naire ( MODQ ) were used in the functional evaluation . Measurements were done before and after 3 weeks of treatment . After the treatment , there were statistically significant improvements in pain severity , patients ' and physician 's global assessment , ROM , RDQ scores , and MODQ scores in all groups ( p < 0.05 ) . However , no significant differences were detected between four treatment groups with respect to all outcome parameters ( p > 0.05 ) . There were no differences between laser and placebo laser treatments on pain severity and functional capacity in patients with acute and chronic low back pain caused by LDH We conducted a double-blind r and omized placebo-controlled study to investigate the effects of short-term 890-nm light therapy in patients with chronic low back pain in a rehabilitation clinic . Thirty-eight women and 22 men with chronic low back pain ( mean age , 60.3 years ; range , 32–80 years ) received 40-min sessions of hot-pack therapy combined with active or placebo 890-nm light therapy ( wavelength = 890 nm , radiant power output = 6.24 W , power density = 34.7 mW/cm2 for 40 min , total energy = 83.2 J/cm2 ) over the lower back three times weekly for 2 weeks . Participants were assessed before and after treatment by using a range of motion measurements , a visual analog scale evaluation of pain , the Multidimensional Fatigue Inventory , the Biodex Stability System , the Fear-Avoidance Beliefs Question naire , repeated chair-rising times , the Frenchay Activity Index , the Oswestry Disability Question naire ( ODQ ) , and the Osteoarthritis Quality of Life Question naire . The severity of disability based on the ODQ score was used as the primary clinical outcome measurement . Compared to the baseline measurements , participants in the treatment group reported significant reductions in fear-avoidance beliefs regarding physical activity ( P = 0.040 ) and work ( P = 0.007 ) and in the severity of disability ( P = 0.021 ) . Treatment with hot-pack therapy and 890-nm light therapy was associated with reductions in the severity of disability and fear avoidance beliefs in patients with chronic low back pain Phototherapy with low-level laser therapy ( LLLT ) and light-emitting diode therapy ( LEDT ) has arisen as an interesting alternative to drugs in treatments of musculoskeletal disorders . However , there is a lack of studies investigating the effects of combined use of different wavelengths from different light sources like lasers and light-emitting diodes ( LEDs ) in skeletal muscle disorders . With this perspective in mind , this study aim ed to investigate the effects of phototherapy with combination of different light sources on nonspecific knee pain . It was performed a r and omized , placebo-controlled , double-blinded clinical trial . Eighty-six patients rated 30 or greater on the pain visual analogue scale ( VAS ) were recruited and included in study . Patients of LLLT group received 12 treatments with active phototherapy ( with 905 nm super-pulsed laser and 875 and 640 nm LEDs , Manufactured by Multi Radiance Medical , Solon , OH , USA ) and conventional treatment ( physical therapy or chiropractic care ) , and patients of placebo group were treated at same way but with placebo phototherapy device .  Pain assessment s ( VAS ) were performed at baseline , 4th , 7th , and 10th treatments , after the completion of treatments and at 1-month follow-up visit . Quality of life assessment s ( SF-36 ® ) were performed at baseline , after the completion of treatments and at 1-month follow-up visit . Our results demonstrate that phototherapy significantly decreased pain ( p < 0.05 ) from 10th treatment to follow-up assessment s and significantly improved ( p < 0.05 ) SF-36 ® physical component summary at posttreatments and follow-up assessment s compared to placebo . We conclude that combination of super-pulsed laser , red and infrared LEDs is effective to decrease pain and improve quality of life in patients with knee pain QUESTION Is low level laser therapy an effective adjuvant intervention for chronic low back pain ? DESIGN R and omised trial with concealed allocation , blinded assessors and intention-to-treat analysis . PARTICIPANTS Sixty-one patients who had low back pain for at least 12 weeks . INTERVENTION One group received laser therapy alone , one received laser therapy and exercise , and the third group received placebo laser therapy and exercise . Laser therapy was performed twice a week for 6 weeks . OUTCOME MEASURES Outcomes were pain severity measured using a 10-cm visual analogue scale , lumbar range of motion measured by the Schober Test and maximum active flexion , extension and lateral flexion , and disability measured with the Oswestry Disability Index on admission to the study , after 6 weeks of intervention , and after another 6 weeks of no intervention . RESULTS There was no greater effect of  laser therapy compared with exercise for any outcome , at either 6 or 12 weeks . There was also no greater effect of laser therapy plus exercise  compared with exercise for any outcome at 6 weeks . However , in the laser therapy plus exercise group pain had reduced by 1.8 cm ( 95 % CI 0.1 to 3.3 , p = 0.03 ) , lumbar range of movement increased by 0. 
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One hypothesis is that there may be an increase in nociceptive threshold after LLLT result ing in neural blockade , specifically an inhibition of A and C neural fibers ( Kudoh et al. , 1989 ; Chow et al. , 2007 ) .
This inhibition may be mediated by altering the axonal flow ( Chow et al. , 2007 ) or by inhibiting neural enzymes ( Kudoh et al. , 1989 ) .
While the mechanisms have not been completely explained , it is clear that LLLT may have an analgesic effect .
This would be classified as a large effect size and suggests a strong inclination for the use of LLLT to reduce chronic pain .
Taken together , it is hard to assess whether LLLT is an effective modality .
There was no additive effect of combining stretching with LLLT in this study .
Both groups reported reductions in pain scores and fatigue .
However , it is clear that LLLT may be beneficial for many individuals suffering from pain , regardless of the condition that is causing it