***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 
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    Input: OBJECTIVE To investigate the analgesic effect of low power radiofrequency electromagnetic radiation ( RF ) in osteoarthritis ( OA ) of the knee . METHODS In a r and omized study on 40 patients the analgesic effect of RF was compared with the effect of transcutaneous electrical nerve stimulation ( TENS ) . RF and TENS applications were repeated every day for a period of 5 days . The therapeutic effect was evaluated by a visual analogue scale ( VAS ) and by Lequesne 's index : tests were performed before , immediately after and 30 days after therapy . RESULTS RF therapy induced a statistically significant and long lasting decrease of VAS and of Lequesne 's index ;  TENS induced a decrease of VAS and of Lequesne 's index which was not statistically significant . CONCLUSIONS A therapeutic effect of RF was therefore demonstrated on pain and disability due to knee OA . This effect was better than the effect of TENS , which is a largely used analgesic technique . Such a difference of the therapeutic effect may be due to the fact that TENS acts only on superficial tissues and nerve terminals , while RF acts increasing superficial and deep tissue temperature CONTEXT Static magnets have become an increasingly popular alternative therapy for individuals with musculoskeletal pain despite limited scientific evidence to support their efficacy or safety . OBJECTIVE To determine the effects of static magnets on the pain and functional limitations associated with chronic knee pain due to degenerative joint disease . DESIGN Double-blind , r and omized , controlled clinical trial . SETTING Pretests and posttests were conducted in an academic health science center . PARTICIPANTS Forty-three ambulatory subjects with chronic pain in 1 or both knee joints who were recruited from outpatient clinics or who volunteered to participate . INTERVENTION Subjects wore pads containing magnets or placebos over their painful knee joints for 2 weeks . MAIN OUTCOME MEASURES Self-administered ratings of pain and physical function using the Western Ontario and McMaster Universities Osteoarthritis Index ( WOMAC ) and a timed 15-m ( 50-ft ) walk . RESULTS Multivariate analysis of covariance revealed significantly greater improvements in the group wearing magnets ( P=.002 ) . Univariate analyses indicated that comparative changes in self-rated pain and physical function ( P=.002 and .001 , respectively ) were greater than changes in gait speed ( P=.042 ) . CONCLUSIONS The application of static magnets over painful knee joints appears to reduce pain and enhance functional movement . However , further study is needed to determine the physiological mechanisms responsible for this analgesic effect This study examined whether a non-thermal , non-invasive , pulsed electromagnetic field ( PEMF ) , known to modulate the calmodulin (CaM)-dependent nitric oxide (NO)/cyclic guanosine monophosphate ( cGMP ) signaling pathway , could reduce pain in early knee OA . This r and omized , placebo-controlled , double-blind pilot clinical study enrolled 34 patients . Patient selection required initial VAS ≥4 , 2 h of st and ing activity per day , and no recent interventions such as cortisone injections or surgery .  Results showed VAS pain score decreased in the active cohort by 50 ± 11 % versus baseline starting at day 1 and persisting to day 42 ( P < 0.001 ) . There was no significant decrease in VAS versus baseline at any time point in the sham cohort ( P = 0.227 ) . The overall decrease in mean VAS score for the active cohort was nearly threefold that of the sham cohort ( P < 0.001 ) . The results suggest that non-thermal , non-invasive PEMF therapy can have a significant and rapid impact on pain from early knee OA and that larger clinical trials are warranted The index for hip disease ( ISH ) was established , vali date d and appraised as a new assessment test for the trial of new drugs as well as for long-term follow-up of patients , and to help with future indications for surgery . The ISH deals with pain , maximum walking distance , and some activities of daily living . Inter-observer reproducibility is good ( mean deviation 0.55 points ; p less than 0.05 ) . In a short-term , double-blind crossover trial , the ISH , judged according to its power to distinguish between the active drug period and the placebo period , appears as one of the best assessment tests . In the long term , total hip prosthesis is most often justified when the ISH score reaches 10 - 12 points . The index of severity for knee disease ( ISK ) was vali date d and appraised by the same statistical methods . Its value in non-steroidal anti-inflammatory drug ( NSAID ) or analgesic trials is lower than the value of the ISH . However , its use is still justified for that purpose , and for long-term follow-up of osteoarthritis of the knee The purpose of this study was to evaluate the effect of electromagnetic field therapy ( PEMF ) on pain , range of motion ( ROM ) and functional status in patients with cervical osteoarthritis ( COA ) . Thirty-four patients with COA were included in a r and omized , double-blind study . PEMF was administrated to the whole body using a mat 1.8 × 0.6 m in size . During the treatment , the patients lay on the mat for 30 min per session , twice a day for 3 weeks . Pain levels in the PEMF group decreased significantly after therapy ( p<0.001 ) , but no change was observed in the placebo group . The active ROM , paravertebral muscle spasm and neck pain and disability scale ( NPDS ) scores improved significantly after PEMF therapy ( p<0.001 ) but no change was observed in the sham group . The results of this study are promising , in that PEMF treatment may offer a potential therapeutic adjunct to current COA therapies in the future BACKGROUND AND METHODS Pulsed magnetic field therapy is frequently used to treat the symptoms of osteoarthritis , although its efficacy has not been proven . We conducted a r and omized , double-blind comparison of pulsed magnetic field and sham therapy in patients with symptomatic osteoarthritis of the knee . Patients were assigned to receive 84 sessions , each with a duration of 30 minutes , of either pulsed magnetic field or sham treatment . Patients administered the treatment on their own at home , twice a day for six weeks . RESULTS According to a sample size estimation , 36 consecutive patients were enrolled . 34 patients completed the study , two of whom had to be excluded from the statistical analysis , as they had not applied the PMF sufficiently . Thus , 15 verum and 17 sham-treated patients were enrolled in the statistical analysis . After six weeks of treatment the WOMAC Osteoarthritis Index was reduced in the pulsed magnetic field-group from 84.1 ( + /- 45.1 ) to 49.7 ( + /- 31.6 ) , and from 73.7 ( + /- 43.3 ) to 66.9 ( + /- 52.9 ) in the sham-treated group ( p = 0.03 ) . The following secondary parameters improved in the pulsed magnetic field group more than they did in the sham group : gait speed at fast walking [ + 6.0 meters per minute ( 1.6 to 10.4 ) vs. -3.2 ( -8.5 to 2.2 ) ] , stride length at fast walking [ + 6.9 cm ( 0.2 to 13.7 ) vs. -2.9 ( -8.8 to 2.9 ) ] , and acceleration time in the isokinetic dynamometry strength tests [ -7.0 % ( -15.2 to 1.3 ) vs. 10.1 % ( -0.3 to 20.6 ) ] . CONCLUSION In patients with symptomatic osteoarthritis of the knee , PMF treatment can reduce impairment in activities of daily life and improve knee function Magnets are widely used by arthritic patients for symptom control . Clinical benefits have been reported from the intermittent application 01 pulsed electromagnetic fields to osteoarthritic joi nts . ’ However . puhl shed trials have used complex electromagnetic fields generated b eumhersomeexpensiveequipment . limiting true portability and widespread use . We report comparable beneficial effects using a continu ous sine ave input to 1-Ielmholz coils run on st and ard household eleetricit\. Fifteen patients with osteoarthritis of at least one knee as defThed by Altman 4 were drawn from the outpatient Adult Rheumatology prac tice of one of the authors ( TDC ) . Patients had to be older than 18 years and symptomatic in the subject knee for at least one year .  Pain had to be incompletely relieved by analgesics . nonsteroidal antiinliammatory drugs ( NSAIDs ) and phsical therapy . No new treatments intra — artieular injection into the subject Joint . PT . NSAIDs were allowed ss ithin a month of . and during the study . Stable regimes were continued . Pregnant and premenopausal women not using contraception were excluded , as were patients with pacemakers or medical problems judged unstable . Subjects applied the supplied magnet to the design ated knee for three hours daily for thirty days . They then returned to the clinic for reevaluation , and to receise the second magnet , which was then similarly applied at home , Of the pairs of magnets sequentially used by each patient , one magnet ( hereinafter referred to as the “ active magnet ” ) consisted of 1-Ielmholz coils delivering a 0,4 milliTesla . peak to peak . electro magnetic field at 60 Hi . in a sine wave configuration ( Fig I. i. The other magnet appeai-ed identical in all respects . hut the fields affecting the ioint s crc the earth ’s magnetic field onl\ . plus ss hat es er stray fields the individual might encounter in daily life ‘ ‘ mac— to . e magnet . Subjects were assigned r and omly to receive either magnet first . The folloving data were collected at baseline , at 3 t ) day ’ tend of treatment period \ Oh the first magnet . and at 60 days end of treatment period with the second magnet patients assessment of pain , and the patient ’s assessment of function on a ten centimeter visual analog scale ( VAS ) , minutes of morning stiffness of the subject knee , range of motion . tenderness on an ordinal scale ofOto 4 ( 0 no tenderness , 4 = withdrawal ) , swelling on an ordinal scale of ( 3 to 4 , knee circumference in cm , and time in seconds for the patient to walk 50 feet , Neither the assessing physician nor the patient knew which magnets were act is e or not . Of the fifteen patients enrolled and r and oniiied . there were tour curly withdrasn als from the eroup that receis ed the inact is e mac— net — one at three days and two at one week for lack of BACKGROUND Optimized pulsed electrical stimulation ( PES ) regulates chondrocyte genes , enhances production of cartilage matrix material s , and inhibits production of matrix catabolic factors . METHODS This prospect i ve , cohort study examined the use of a PES device in treatment of  knee osteoarthritis ( OA ) in patients who had failed non-operative therapy . Primary outcome measures were patient and physician global evaluation , and patient assessment of knee pain . RESULTS This study included 288 ( 95 men , 193 women ) patients who used the device from 16 to more than 600 days ( mean : 889 hours ) . Improvement in all efficacy variables ( p < 0.001 ) occurred . A dose-response relationship between effect size and hours of usage was observed as cumulative time increased to more than 750 hours . Improvement in patient or physician global occurred in 59.0 % of patients who used it less than 750 hours , and for 73.0 % of those who used it more than 750 hours . An economic analysis of a sub-group of patients showed that 45.3 % reduced nonsteroidal anti-inflammatory drug ( NSAID ) use by 50.0 % or more . CONCLUSIONS A highly optimized PES device successfully attenuated knee OA  symptoms in patients who had failed non-surgical therapy . Less than 250 hours of therapy provided relief , but improvement increased in a dose-response manner after 750 hours of cumulative use Within the context of a double blind r and omized controlled parallel trial of 2 nonsteroidal antiinflammatory drugs , we vali date d WOMAC , a new multidimensional , self-administered health status instrument for patients with osteoarthritis of the hip or knee . The pain , stiffness and physical function subscales fulfil conventional criteria for face , content and construct validity , reliability , responsiveness and relative efficiency . WOMAC is a disease-specific purpose built high performance instrument for evaluative research in osteoarthritis clinical trials Pulsing electromagnetic field represents effective rocedure in treating of diverse diseases and p pathologic conditions , especially in rheumatology , orthopaedics and traumatology . The goal of this research is the objective evaluation of the treapeutic effect of low frequency pulsing electromagnetic field ( LFEMF ) , in comparison with the effect of the other physical procedure : interfererence currents ( IFC ) and the medicamentous therapy , in treating of patients with knee joint osteoarthritis . This study was made as experimental , r and omized , controlled clinical trial , opened type . The examination included 60 patients ( 40 females and 20 males ) with osteoarthritis of the knee joint . All patients were divided in three groups . The first group of 2 
    Output:
    
AUTHORS ' CONCLUSIONS Current evidence suggests that electromagnetic field treatment may provide moderate benefit for osteoarthritis sufferers in terms of pain relief .