***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: A prospect i ve study of the use of transcutaneous neural stimulation ( TNS ) in 90 arthroscopic knee surgery pa tients was performed to determine : ( 1 ) if TNS is as effective as traditional pain medication in treating post operative knee pain ; and ( 2 ) if patients that had received TNS regain preoperative motion and strength quicker than the control population . The patients were divided into three equal groups . Group I consisted of patients with no TNS unit  , Group II had a " placebo " unit  , and Group III had a " live " unit . Preoperatively , each patient received an isokinetic muscle examination , orientation to the TNS unit , leg circumference measurements , and exercise instruction . An isokinetic muscle examination and leg circumference measurements were repeated at 1 , 3 , and 7 weeks postoperatively . Additionally , the amount of pain and medication required was analyzed . The results of the study indicated that the use of a TNS unit is an effective adjunct in decreasing postoperative pain in 93 % of patients . The amount of pain and total pain medication required was greatest in the control group , less in the placebo , and markedly reduced in the TNS group . A comparison among the three groups revealed that the TNS group regained the following preoperative values 1 month sooner than the other two groups ( 3 as opposed to seven weeks postoperatively ) : isokinetic power in flexion and extension ( P < 0.05 ) , range of motion ( P < 0.02 ) , and leg volume ( P < 0.05 ) . There was no correlation between the pain and irregular wave forms on the isokinetic graph . The only compli cation noted was skin irritation at the electrode sites . TNS has been shown to be a significant benefit in the treatment of postoperative knee pain and in hastening recovery of muscular function through a full range of motion Thirty-six non-hospitalized subjects with chronic pain from OA of the knee participated in an evaluation of transcutaneous electrical nerve stimulation ( TENS ) and naproxen , an NSAID . All pre-experiment treatment was withdrawn . Each subject experienced in some order three 3-week treatment phases : NSAID plus placebo TENS ; TENS plus placebo drug ; and double placebo . A broad range of pain measures was used , including daily diary ratings , and four-times-per-day ratings entered into a small electronic data logger ( the PIPER ) worn by the subject . A substantial placebo response occurred across all conditions , which may have masked treatment differences . Broad comparisons across subjects , combining the four main measures of pain , found no significant differences among the three experimental treatments . Analysis of diary and PIPER data for individuals suggested that , in a small minority of subjects , the NSAID plus placebo TENS combination may be more effective than double placebo . The PIPER ratings seemed to tap aspects of the pain experience different from those captured by conventional measures , suggesting the value of very frequent pain assessment s , such as those entered by a subject into the PIPER , in the study of chronic pain Assessing the quality of r and omized controlled trials ( RCTs ) is important and relatively new . Quality gives us an estimate of the likelihood that the results are a valid estimate of the truth . We present an annotated bibliography of scales and checklists developed to assess quality . Twenty-five scales and nine checklists have been developed to assess quality . The checklists are most useful in providing investigators with guidelines as to what information should be included in reporting RCTs . The scales give readers a quantitative index of the likelihood that the reported methodology and results are free of bias . There are several shortcomings with these scales . Future scale development is likely to be most beneficial if questions common to all trials are assessed , if the scale is easy to use , and if it is developed with sufficient rigor This r and omized study analyzed the effectiveness of postoperative transcutaneous electrical nerve stimulation ( TENS ) used continuously for the first three postoperative days following total knee replacement ( TKR ) for 1 ) pain relief , 2 ) knee flexion arc , 3 ) narcotic dosage , and 4 ) hospital stay . Group 1 ( N = 18 ) received sensory threshold TENS and group 2 ( N = 18 ) received subthreshold TENS . Both groups also used continuous passive motion during their hospitalization as did patients from group 3 ( control , N = 12 ) that did not receive TENS .  Pain decrease from postoperative day 1 - 3 was 50 % for group 1 patients and 38 % for group 2 patients , as measured by the visual analog scale . Wilcoxon Rank Sum did not show a significant difference ( p > 0.05 ) for pain relief or hospital stay for these two groups . Analysis of variance failed to show significant differences ( p > 0.05 ) for knee flexion arc or narcotic dosage for the three groups . Although not statistically significant , an observed decrease in pain may be the only indication for postoperative TENS after TKR . J Orthop Sports Phys Ther 1990;11(12):599 - 604 Summary The analgesic effects of high frequency transcutaneous electrical nerve stimulation ( TNS ) , “ acupuncture-like ” TNS and placebo TNS were evaluated in 33 patients with rheumatoid arthritis and chronic h and pain using a r and omized , double-blind , non-crossover design . An oscilloscope was employed to monitor the stimulator output in the TNS treatment groups and to provide strong suggestion and a focus of attention in the placebo treatment group . The two forms of TNS were applied at the highest intensity that could be tolerated by patients . Assessment s of resting pain , joint tenderness , grip strength and grip pain were made before and after treatment . The pain and joint tenderness measurements showed high frequency TNS , “ acupuncture-like ” TNS and placebo TNS to be equally effective in producing analgesia of similar degree and trend over time . The grip strength measurements showed no significant change . The results obtained with placebo are probably due to the suggestion and attention effects of the visual stimulus . The implication s of these results in respect to pain control pathways are discussed . Although TNS given at high intensity was shown to be no better than placebo applied with strong suggestion , this does not preclude its use as a method of pain control in rheumatoid arthritis The therapeutic effect of once weekly transcutaneous electrical nerve stimulation in patients with rheumatoid arthritis was compared with placebo in a r and omised , double-blind , non-crossover study lasting three weeks . Thirty-two patients with classic or definite rheumatoid arthritis and wrist involvement were evaluated . Transcutaneous electrical nerve stimulation was better than the placebo in relieving pain at rest and while gripping . In addition , grip strength , measured as power and work done , immediately improved following transcutaneous electrical nerve stimulation but returned almost to initial values between assessment s. No significant improvement was shown for the placebo group The effect of transcutaneous nerve stimulation ( TNS ) on joint pain was studied in patients with rheumatoid arthritis .  Three different forms of TNS were used in an attempt to evaluate the influence of placebo effects . The results were evaluated by means of loading tests and from the patients ' own assessment s of pain relief . High intensity TNS near the painful joint gave pain relief of varying degree in 95 % of the patients , while TNS of low intensity and TNS applied at a remote site gave an improvement in 75 % and 5 % respectively . It seems quite clear that TNS is effective in reducing joint pain . There are a number of factors which intimate that this improvement is not merely a placebo effect The effect of transcutaneous nerve stimulation ( TNS ) was evaluated and compared with placebo TNS in 19 patients ( 17 women , mean age 33 years ) with orofacial functional pain and rheumatic disease involving the temporom and ibular joint . In two double-blind noncrossover experiments , high frequency TNS ( 100 Hz ) and low frequency TNS ( 2 Hz ) were evaluated by comparison of the patients ' functional and rest pain , muscle and joint tenderness , and jaw function . A significant treatment effect was obtained for all treatment methods regarding functional and rest pain and muscle and joint tenderness . None of the parameters except functional pain , which improved significantly more after high frequency TNS than placebo TNS , revealed any difference between the methods . Jaw function , however , revealed a few differences between high frequency TNS and placebo TNS 
    Output:
    
Results showed a statistically significant reduction in joint tenderness , but no clinical benefit from C-TENS over placebo in relief of joint tenderness .
REVIEW ER 'S CONCLUSIONS There are conflicting effects of TENS on pain outcomes in patients with RA .
AL-TENS is beneficial for reducing pain intensity and improving muscle power scores over placebo while , conversely , C-TENS result ed in no clinical benefit on pain intensity compared with placebo .
However C-TENS result ed in a clinical benefit on patient assessment of change in disease over AL-TENS .
More well design ed studies with a st and ardized protocol and adequate number of subjects are needed to fully conclude the effect of C-TENS and AL-TENS in the treatment of RA of the h and