***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: This study aim ed to evaluate the effectiveness of transcutaneous electrical nerve stimulation ( TENS ) for treatment of  postoperative pain in patients who underwent cardiac surgery . In addition , we sought to determine whether TENS would be related to improved pulmonary function and muscle electrical activity in this patient population . Forty-five patients , 32 males and 13 females , aged 41 - 74 years were r and omly allocated to receive TENS ( n=23 ) or sham treatment ( n=22 ) during 4 h on the third postoperative day . A 0 - 10 visual analogic scale was used to assess pain ; lung function was evaluated by spirometry and surface electromyography ( n=10 in each group ) was used to quantify electrically-induced muscle activity ( trapezius and pectoralis major ) . TENS was associated with significant reductions on spontaneous and cough-induced postoperative pain as compared to sham ( P<0.05 ) . There was also improvement in chest wall-pulmonary mechanics after TENS with proportional increases in tidal volume and vital capacity ( P<0.05 ) . In addition , electrical activity of both muscle groups was enhanced after TENS , but not post sham ( P<0.05 ) . TENS is a valuable strategy to alleviate postoperative pain following cardiac surgery with positive effects on pulmonary ventilatory function and electrical activity of thoracic and girdle muscles Therapeutic trials often attempt to “ blind ” patient and investigator to the true nature of treatments received , reducing the influences of conscious or subconscious prejudices . In drug trials , this is accomplished with placebo tablets , but blinding in trials of physical treatments is more problematic . This issue arose in a clinical trial of transcutaneous electrical nerve stimulation ( TENS ) for patients with chronic low back pain . Several study design features were incorporated to promote blinding : use of sham TENS units visually identical with real units , exclusion of potential subjects with previous TENS experience , avoidance of a crossover design and use of identical visit frequency , instructions and modifications in electrode placement . Subjects were asked not to discuss treatments with the clinicians who performed outcome assessment s. Both patients and clinicians were asked to guess actual treatment assignments at the trial 's end . Every patient in the true TENS group believed the unit was functioning properly , but the degree of certainty varied . In the sham TENS group , 84 % also believed they had functioning units , but their certainty was significantly less than in the active treatment group . Differences in patient perceptions did not affect compliance , as the two groups had similar dropout rates , appointment compliance , days of TENS use and daily duration of TENS use . Clinicians guessed treatments correctly 61 % of the time ( as opposed to 50 % expected by chance ) , again suggesting partial success in blinding . These efforts at blinding may partly explain the negative trial results for TENS efficacy . We conclude that complete blinding is difficult to achieve because of sensory difference in treatment and unintended communication between patient and examiner . Nonetheless , trials of physical treatments can achieve partial blinding with the techniques described here , and the success of blinding can be assessed with simple questions at study completion Study Design . R and omized , controlled , multi-center trial . Objective . To investigate the effect of direct current ( DC ) electrical stimulation on functional and clinical outcome after lumbar spinal fusion in patients older than 60 years . Summary of Background Data . Older patients have increased complication rates after spinal fusion surgery . Treatments which have the possibility of enhancing functional outcome and fusion rates without lengthening the procedure could prove beneficial . DC-stimulation of spinal fusion has proven effective in increasing fusion rates in younger and “ high risk ” patients , but functional outcome measures have not been reported . Methods . A r and omized , clinical trial comprising 5 orthopedic centers . The study included a total of 107 patients r and omized to uninstrumented posterolateral lumbar spinal fusion with or without DC-stimulation .  Functional outcome was assessed using Dallas Pain Question naire , SF-36 , Low Back Pain Rating Scale pain index , and walking distance . Results . Follow-up after 1 year was 95/107 ( 89 % ) . DC-stimulated patients had significant better outcome in 3 of 4 categories in the Dallas Pain Question naire , better SF-36 scores ( not significantly ) , but no difference in pain scores were observed . Median walking distance at latest follow-up was better in the stimulated group ( not significant ) . Walking distance was significantly associated with functional outcome . There was no difference in any of the functional outcome scores between patients who experienced a perioperative complication and those without complications . Conclusion . The achievement of a good functional outcome was heavily dependent on the obtained walking distance . DC-stimulated patients tended to have better functional outcome as compared to controls . No negative effects of perioperative complications could be observed on the short-term functional outcome Transcutaneous electrical nerve stimulation ( TENS ) has been used to treat chronic pain syndromes and has been reported to be of some utility in the treatment of postsurgical pain . A r and omized , blinded , placebo-controlled trial was design ed to evaluate the utility of TENS  after total knee arthroplasty . Patients were r and omly enrolled into patient-controlled anesthesia ( PCA ) alone , PCA plus TENS , or PCA plus sham TENS .  The cumulative dose of morphine by PCA for each group was used as the end-point of the study . There was no significant reduction in the requirement for patient-controlled analgesia with or without TENS . We conclude that there is no utility for TENS in the postoperative management of pain after knee arthroplasty The aim of this clinical trial was to evaluate the effects of electrical stimulation ( ES ) program on trunk muscle strength , functional performance , quality of life ( QOL ) in the patients with chronic low back pain ( CLBP ) . A total of 41 patients with definite CLBP were included in this study . These patients were r and omized into two groups . Group 1 ( n = 21 ) was given an ES program and exercises . Group 2 ( n = 20 ) was accepted as the control group and given only exercises . Both the programs were performed 3 days a week , for 8 weeks in the out-patient department . The patients were evaluated according to pain , disability , functional performance , endurance , quality of life , depression . The muscle strengths were measured with a h and -held dynamometer . There were significant improvements for all the parameters in two groups after the treatment . Except depression and social function , the improvements for all the parameters were better in the ES group than in the control group . We observed that ES program was very effective in improving QOL , functional performance and isometric strength . In conclusion , we can say that ES therapy provides comfortable life functions by improving muscle strength , functional performance and QOL OBJECTIVE Few non-surgical conditions are more painful than rib fractures . There are a few methods for pain relief in patients with minor rib fractures . METHODS We used a non-steroidal anti-inflammatory drug ( NSAID , Naproxen sodium ) and transcutaneous electrical nerve stimulator ( TENS ) to control pain of the patients with uncomplicated minor rib fractures . One hundred consecutive patients admitted to Kartal Education and Research Hospital Emergency Service , were r and omized into four groups . The patients were assigned to one of the following pain treatments : NSAID , TENS , NSAID plus inactive TENS or placebo . The patients used NSAIDs and placebo four times a day and TENS twice a day for 3 days . All patients were asked to assess their pain level with a scoring system on days 0 , 1 and 3 . RESULTS The most effective treatment was TENS on days 1 and 3 ( P<0.05 ) . Although NSAID and NSAID plus inactive TENS  controlled pain better than placebo on day 1 ( P<0.05 ) , this superiority did not continue to day 3 ( P>0.05 ) . There was no difference between NSAID and NSAID plus inactive TENS in controlling pain on either days 1 or 3 . CONCLUSION We conclude that TENS was more effective than NSAID or placebo in patients with uncomplicated minor rib fractures , because of its prominent and admirable efficacy in reduction of pain Sciatica is a common pain problem and current pharmacologic therapies have proven inadequate for many patients . The objective of this sham-controlled investigation was to compare a novel non-pharmacologic technique , percutaneous electrical nerve stimulation ( PENS ) , to transcutaneous electrical nerve stimulation ( TENS ) in the management of the radicular pain associated with sciatica . Sixty-four consenting patients with sciatica due to lumbar disc herniation were treated with PENS , TENS and sham-PENS according to a r and omized , single-blinded , cross-over study . All patients had been maintained on a stable oral non-opioid analgesic regimen for at least 6 weeks prior to entering the study . Each treatment modality was administered for a period of 30 min three times per week for 3 weeks , with 1 week ' off ' between each modality . Both PENS and TENS treatments were administered using a stimulation frequency of 4 Hz . The pre-treatment assessment included the health status survey short form ( SF-36 ) , as well as visual analog scales ( VAS ) for radicular pain , physical activity and quality of sleep . The pain VAS was also repeated after each treatment session . At the end of each 3-week treatment block , the SF-36 was repeated . After receiving all three treatment modalities , a global assessment question naire was completed . Both PENS ( 42 % ) and TENS ( 23 % ) were significantly more effective than the sham ( 8 % ) treatments in decreasing VAS pain scores . The daily oral analgesic requirements were also significantly reduced compared to the pre-treatment values with PENS ( P<0.01 ) and TENS ( P<0.05 ) . However , PENS was significantly more effective than TENS ( and sham-PENS ) in improving physical activity and quality of sleep . The SF-36 evaluation confirmed the superiority of PENS ( versus TENS and sham-PENS ) with respect to post-treatment functionality . In the overall assessment , 73 % of the patients reported that PENS was the most desirable modality ( versus 21 % for TENS and 6 % for sham-PENS ) . Finally , 71 % of the patients stated that they would be willing to pay extra to receive PENS therapy compared to 22 % and 3 % for TENS and sham-PENS , respectively . In this sham-controlled study , we concluded that PENS was more effective than TENS when administered at a stimulation frequency of 4 Hz in providing short-term pain relief and improved functionality in patients with sciatica Twenty patients undergoing decompressive lumbar laminectomy were r and omly allocated , in a double-blind manner , to receive active or inactive transcutaneous electrical nerve stimulation ( TENS ) as part of the management of their postoperative pain . All patients received the same non-narcotic general anaesthetic . The efficacy of the TENS was assessed by using a  patient-controlled analgesia system ( PRODAC )  which delivered morphine i.v . This system recorded the number of dem and s for analgesia and the total dose administered in the first 24 h. In addition , plasma morphine concentrations were measured hourly for the first 6 h and again at 24 h. There was no statistical difference between the two groups in the number of patient dem and s for analgesia , morphine dose or plasma morphine concentration .  TENS offered no advantage over a placebo in the management of acute postoperative pain in these patients OBJECTIVES To compare the efficacy of combined transcutaneous acupoint electrical stimulation ( TAES ) and electromagnetic millimeter wave ( EMMW ) therapy as an add-on treatment for pain relief and physical functional activity enhancement among adults with sub-acute non-specific spinal pain in either the low back or neck . DESIGN A non-blinded study with data obtained before , immediate , one week and three months after intervention . SETTING The Telehealth Clinic and Community Centre , Hong Kong . PARTICIPANTS Forty-seven subjects with either sub-acute neck or low back pain . INTERVENTION Subjects were r and omly allocated to either an intervention group ( n=23 ) or a control group ( n=24 ) . These groups were then divided into subgroups according to the site of their spinal pain-neck or back . The intervention group had eight treatments over a three-week period of TAES and EMMW . OUTCOME MEASURES Changes from baseline to the end of treatment were assessed at intervals of one week and three months on either neck or low back pain intensity [ by Visual Analogue Scale ( VAS ) ] ; stiffness level ; stress level ; neck or low back lateral flexion and forward flexion in cm , and interference with daily activities . RESULTS The baseline VAS scores for the intervention and control groups were 5.34 and 5.18 out of 10 , respectively ( P value=0.77 ) . At the one week and three month assessment s , there were no significant differences between the groups-VAS ( P value=0.09 and 0.27 , respectively ) . A further subgroup of chronic pain sufferers ( n=31 ) was identified and these had significantly reduced pain intensity at the one week assessment ( P value=0.04 ) but this was not sustained at post three months after treatment ( P value=0.15 ) . Improvements in stiffness level , stress level , and functional disability level in the intervention group were not significant . CONCLUSIONS Our study shows that there was a reduction in pain intensity , stress and stiffness level immediately after the eight sessions of treatment ( TAES and EMMW ) , though the effect is not sustained after a week . No pain relief was found with the neck pain subgroup . However , the reduction in subjective average pain intensity among the chronic pain subgroup was sustained at the post one week assessment for the intervention group but not at the post three month assessment Venipuncture continues 
    Output:
    
Due to insufficient extractable data in the studies included in this review , we are unable to make any definitive conclusions about the effectiveness of TENS as an isolated treatment for acute pain in adults