The clinical and cost-effectiveness of corticosteroid injection versus night splints for carpal tunnel syndrome (INSTINCTS trial): an open-label, parallel group, randomised controlled trial.

BACKGROUND: To our knowledge, the comparative effectiveness of commonly used conservative treatments for carpal tunnel syndrome has not been evaluated previously in primary care. We aimed to compare the clinical and cost-effectiveness of night splints with a corticosteroid injection with regards to reducing symptoms and improving hand function in patients with mild or moderate carpal tunnel syndrome. METHODS: We did this randomised, open-label, pragmatic trial in adults (≥18 years) with mild or moderate carpal tunnel syndrome recruited from 25 primary and community musculoskeletal clinics and services. Patients with a new episode of idiopathic mild or moderate carpal tunnel syndrome of at least 6 weeks' duration were eligible. We randomly assigned (1:1) patients (permutated blocks of two and four by site) with an online web or third party telephone service to receive either a single injection of 20 mg methylprednisolone acetate (from 40 mg/mL) or a night-resting splint to be worn for 6 weeks. Patients and clinicians could not be masked to the intervention. The primary outcome was the overall score of the Boston Carpal Tunnel Questionnaire (BCTQ) at 6 weeks. We used intention-to-treat analysis, with multiple imputation for missing data, which was concealed to treatment group allocation. The trial is registered with the European Clinical Trials Database, number 2013-001435-48, and ClinicalTrial.gov, number NCT02038452. FINDINGS: Between April 17, 2014, and Dec 31, 2016, 234 participants were randomly assigned (118 to the night splint group and 116 to the corticosteroid injection group), of whom 212 (91%) completed the BCTQ at 6 weeks. The BCTQ score was significantly better at 6 weeks in the corticosteroid injection group (mean 2·02 [SD 0·81]) than the night splint group (2·29 [0·75]; adjusted mean difference -0·32; 95% CI -0·48 to -0·16; p=0·0001). No adverse events were reported. INTERPRETATION: A single corticosteroid injection shows superior clinical effectiveness at 6 weeks compared with night-resting splints, making it the treatment of choice for rapid symptom response in mild or moderate carpal tunnel syndrome presenting in primary care. FUNDING: Arthritis Research UK.

Coexistence of plantar calcaneal spurs and plantar fascial thickening in individuals with plantar heel pain.

Objectives: To examine associations between plantar calcaneal spurs, plantar fascia thickening and plantar heel pain (PHP), and to determine whether tenderness on palpation of the heel differentiates between these presentations. Methods: Adults aged ⩾50 years registered with four general practices were mailed a Health Survey. Responders reporting foot pain within the last 12 months underwent a detailed clinical assessment. PHP in the past month was documented using a foot manikin. Plantar calcaneal spurs were identified from weight-bearing lateral radiographs and plantar fascia thickening (defined as >4 mm) from ultrasound. Tenderness on palpation of the plantar fascia insertion was documented. Associations between these factors and PHP were explored using generalized estimating equations. Results: Clinical and radiographic data were available from 530 participants (296 women, mean [s.d.] age 64.9 [8.4] years), 117 (22.1%) of whom reported PHP. Plantar calcaneal spurs and plantar fascia thickening were identified in 281 (26.5%) and 501 (47.3%) feet, respectively, but frequently coexisted (n = 217, 20.4%). Isolated plantar calcaneal spurs were rare (n = 64, 6.0%). Participants with PHP were more likely to have a combination of these features compared with those without PHP (odds ratio 2.16, 95% CI 1.24, 3.77, P = 0.007). Tenderness on palpation of the heel was not associated with plantar calcaneal spurs or plantar fascia thickening, either in isolation or in combination, in those with PHP. Conclusion: Plantar calcaneal spurs and plantar fascial thickening are associated with PHP, but frequently coexist. Tenderness on palpation of the heel does not appear to differentiate between clinical presentations of PHP.

Comparative effectiveness of treatment options for plantar heel pain: a systematic review with network meta-analysis.

OBJECTIVE: To evaluate the comparative effectiveness of current treatment options for plantar heel pain (PHP). DESIGN: Systematic review and network meta-analysis (NMA). DATA SOURCES: Medline, EMBASE, CINAHL, AMED, PEDro, Cochrane Database, Web of Science and WHO Clinical Trials Platform were searched from their inception until January 2018. STUDY SELECTION: Randomised controlled trials (RCTs) of adults with PHP investigating common treatments (ie, corticosteroid injection, non-steroidal anti-inflammatory drugs, therapeutic exercise, orthoses and/or extracorporeal shockwave therapy (ESWT)) compared with each other or a no treatment, placebo/sham control. DATA EXTRACTION AND ANALYSIS: Data were extracted and checked for accuracy and completeness by pairs of reviewers. Primary outcomes were pain and function. Comparative treatment effects were analysed by random effects NMA in the short term, medium term and long term. Relative ranking of treatments was assessed by surface under the cumulative ranking probabilities (0-100 scale). RESULTS: Thirty-one RCTs (total n=2450 patients) were included. There was no evidence of inconsistency detected between direct and indirect treatment comparisons in the networks, but sparse data led to frequently wide CIs. Available evidence does not suggest that any of the commonly used treatments for the management of PHP are better than any other, although corticosteroid injections, alone or in combination with exercise, and ESWT were ranked most likely to be effective for the management of short-term, medium-term and long-term pain or function; placebo/sham/control appeared least likely to be effective; and exercise appeared to only be beneficial for long-term pain or function. CONCLUSIONS: Current evidence is equivocal regarding which treatment is the most effective for the management of PHP. Given limited understanding of long-term effects, there is need for large, methodologically robust multicentre RCTs investigating and directly comparing commonly used treatments for the management of PHP. PROSPERO REGISTRATION NUMBER: CRD42016046963.

Clinical Course and Prognostic Factors in Conservatively Managed Carpal Tunnel Syndrome: A Systematic Review.

OBJECTIVE: To summarize the available evidence regarding the course of symptoms and prognostic factors in patients with diagnosed carpal tunnel syndrome (CTS) who are treated conservatively. DATA SOURCES: Computerized databases, reference checking, and experts in the field were used to identify studies for inclusion in the review. STUDY SELECTION: Multiple reviewers were used to identify studies which included adults (aged ≥18y) diagnosed with CTS in either a clinical setting or population setting. The study must have observed the course of CTS over at least a 6-week period in patients receiving no treatment or usual care that included conservative (nonsurgical) treatments. The design was of a longitudinal cohort study with either prospective or retrospective data collection. There were no language restrictions, and none of the research identified was only reported in abstract form. DATA EXTRACTION: Methodological bias was assessed using the Quality in Prognosis Studies tool. A high risk of bias (predominantly relating to study attrition, confounding, and/or statistical analysis and reporting) was judged to be present in 8 studies. Designs showed wide variability with respect to characteristics of the included population, definition of CTS, assessment of prognostic factors, types of interventions provided, and types of outcome measures applied. This prevented pooled estimates from being produced. DATA SYNTHESIS: A negative outcome at 3 years' follow-up of conservatively treated participants ranged from 23% to 89%. Four included studies observed the rate of surgical intervention after initial conservative management and found this to be 57% to 66%. Evidence regarding factors predicting the negative outcome of no treatment or conservative treatment was graded, taking into account the number of studies evaluating the factor, the methodological quality of these studies, and the consistency of the available evidence. There was 100% agreement in at least 3 cohorts with a medium or high risk of bias that symptom duration, a positive Phalen's test, and thenar wasting were associated with a negative outcome of conservative management; however, not all results were statistically significant, and hence the overall judgment remained inconclusive. CONCLUSIONS: Results of this review should be treated with caution because of the heterogeneity of studies and the risks of bias identified. However, the course of CTS appears variable, and poor prognosis may be predicted by a longer symptom duration, a positive Phalen's test, and thenar wasting.

The clinical and cost effectiveness of steroid injection compared with night splints for carpal tunnel syndrome: the INSTINCTS randomised clinical trial study protocol.

BACKGROUND: Patients diagnosed with idiopathic mild to moderate carpal tunnel syndrome (CTS) are usually managed in primary care and commonly treated with night splints and/or corticosteroid injection. The comparative effectiveness of these interventions has not been reliably established nor investigated in the medium and long term. The primary objective of this trial is to investigate whether corticosteroid injection is effective in reducing symptoms and improving hand function in mild to moderate CTS over 6 weeks when compared with night splints. Secondary objectives are to determine specified comparative clinical outcomes and cost effectiveness of corticosteroid injection over 6 and 24 months. METHOD/DESIGN: A multicentre, randomised, parallel group, clinical pragmatic trial will recruit 240 adults aged ≥18 years with mild to moderate CTS from GP Practices and Primary-Secondary Care Musculoskeletal Interface Clinics. Diagnosis will be by standardised clinical assessment. Participants will be randomised on an equal basis to receive either one injection of 20 mg Depo-Medrone or a night splint to be worn for 6 weeks. The primary outcome is the overall score of the Boston Carpal Tunnel Questionnaire (BCTQ) at 6 weeks. Secondary outcomes are the BCTQ symptom severity and function status subscales, symptom intensity, interrupted sleep, adherence to splinting, perceived benefit and satisfaction with treatment, work absence and reduction in work performance, EQ-5D-5L, referral to surgery and health utilisation costs. Participants will be assessed at baseline and followed up at 6 weeks, 6, 12 and 24 months. The primary analysis will use an intention to treat (ITT) approach and multiple imputation for missing data. The sample size was calculated to detect a 15 % greater improvement in the BTCQ overall score in the injection group compared to night-splinting at approximately 90 % power, 5 % two-tailed significance and allows for 15 % loss to follow-up. DISCUSSION: The trial makes an important contribution to the evidence base available to support effective conservative management of CTS in primary care. No previous trials have directly compared these treatments for CTS in primary care populations, reported on clinical effectiveness at more than 6 months nor compared cost effectiveness of the interventions. TRIAL REGISTRATION: Trial registration: EudraCT 2013-001435-48 (registered 05/06/2013), ClinicalTrials.gov NCT02038452 (registered 16/1/2014), and Current Controlled Trials ISRCTN09392969 (retrospectively registered 01/05/2014).

Transcutaneous electrical nerve stimulation as adjunct to primary care management for tennis elbow: pragmatic randomised controlled trial (TATE trial).

STUDY QUESTION: Can transcutaneous electrical nerve stimulation (TENS), as a patient controlled adjunct to primary care management for tennis elbow, provide superior pain relief to primary care management alone. SUMMARY ANSWER: TENS conferred no additional clinical benefit over primary care management consisting of information and advice on analgesia and exercise for patients with tennis elbow, probably partly owing to poor adherence to treatment recommendations. WHAT IS KNOWN AND WHAT THIS PAPER ADDS: A need exists for safe, self administered interventions to provide pain relief for patients with tennis elbow. TENS as an adjunct to primary care management failed to show any additional pain relief compared with primary care management alone.

Self-management advice, exercise and foot orthoses for plantar heel pain: the TREADON pilot and feasibility randomised trial.

BACKGROUND: Plantar heel pain (PHP) is common and impacts negatively on physical function and quality of life. Initial treatment usually comprises analgesia and self-management advice (SMA), with referral to a physiotherapist or podiatrist recommended only when symptoms persist. Systematic reviews highlight limitations of existing evidence for the effectiveness of exercises and orthoses. The objective of the TREADON pilot and feasibility trial was to inform the design of a future main trial to compare the clinical and cost-effectiveness of self-management advice (SMA), individualised exercises and foot orthoses for PHP. METHODS: This was a four-arm randomised feasibility and pilot trial with 12-week follow-up. Adults aged ≥ 18 years with PHP were identified from primary care by general practice consultation, retrospective general practice medical record review or a population survey. Participants were randomised to either (i) SMA, (ii) SMA plus individualised exercises (SMA-exercises), (iii) SMA plus prefabricated foot orthoses (SMA-orthoses) or (iv) SMA plus combined individualised exercises and prefabricated foot orthoses (SMA-combined). Feasibility outcomes were recruitment; retention; intervention adherence, credibility and satisfaction; performance of three potential primary outcome measures (pain numeric rating scale (NRS), Foot Function Index-pain subscale (FFI-pain), Manchester Foot Pain and Disability Index-pain subscale (MFPDI-pain)); and parameters for informing the main trial sample size calculation. RESULTS: Eighty-two participants were recruited. All three identification methods met the target number of participants. Retention at 12 weeks was 67%. All interventions were successfully delivered as per protocol. Adherence (range over 12 weeks 64-100%) and credibility (93%) were highest in the SMA-combined arm. Satisfaction with treatment was higher for the three clinician-supported interventions (SMA 29%, SMA-exercises 72%, SMA-orthoses 71%, SMA-combined 73%). Responsiveness (baseline to 12 weeks) was higher for FFI-pain (standardised response mean 0.96) and pain NRS (1.04) than MFPDI-pain (0.57). Conservative sample size parameter estimates for standard deviation were pain NRS 2.5, FFI-pain 25 and MFPDI-pain 4, and baseline-outcome correlations were 0.5-0.6, 0.4 and < 0.3, respectively. CONCLUSIONS: We demonstrated the feasibility of conducting a future main randomised clinical trial comparing the clinical and cost-effectiveness of SMA, exercises and/or foot orthoses for PHP. TRIAL REGISTRATION NUMBER: ISRCTN 12160508 . Prospectively registered 5th July 2016.

Transcutaneous electrical nerve stimulation for the management of tennis elbow: a pragmatic randomized controlled trial: the TATE trial (ISRCTN 87141084).

BACKGROUND: Tennis elbow is a common and often extremely painful musculoskeletal condition, which has considerable impact on individuals as well as economic implications for healthcare utilization and absence from work. Many management strategies have been studied in clinical trials. Whilst corticosteroid injections offer short term pain relief, this treatment is unpleasant and is used with caution due to an associated high risk of pain recurrence in the long term. Systematic reviews conclude that there is no clear and effective treatment for symptoms of pain in the first 6 weeks of the condition. There is a clear need for an intervention that is acceptable to patients and provides them with effective short-term pain relief without increasing the risk of recurrence. Transcutaneous electrical nerve stimulation (TENS) is an inexpensive, non-invasive, non-pharmacological form of analgesia that is commonly used in the treatment of pain. TENS has very few contraindications and is simple to apply. It also benefits from being patient controlled, thereby promoting self-management. This study aims to assess the effectiveness, in terms of pain relief, and cost-effectiveness of a self-management package of treatment that includes TENS. METHODS/DESIGN: The design of the study will be a two-group pragmatic randomized clinical trial. 240 participants aged 18 years and over with tennis elbow will be recruited from 20-30 GP practices in Staffordshire, UK. Participants are to be randomized on a 1:1 basis to receive either primary care management (standard GP consultation, medication, advice and education) or primary care management with the addition of TENS, over 6 weeks. Our primary outcome measure is average intensity of elbow pain in the past 24 hours (0-10 point numerical rating scale) at 6 weeks. Secondary outcomes include pain and limitation of function, global assessment of change, days of sick leave, illness perceptions, and overall health status. A cost-effectiveness analysis will also be performed. Patient adherence and satisfaction data will be collected at 6 weeks, 6 months and 12 months by postal questionnaire. A diary will also be completed for the first 2 weeks of treatment. Clinical effectiveness and cost-effectiveness analyses will be carried out using an intention-to-treat approach as the primary analysis. DISCUSSION: This paper presents detail on the rationale, design, methods and operational aspects of the trial. TRIAL REGISTRATION: Current Controlled Trials. ISRCTN87141084.

Predicting surgical intervention in patients presenting with carpal tunnel syndrome in primary care.

PURPOSE: Carpal tunnel syndrome (CTS) is a symptomatic compression neuropathy of the median nerve. This study investigated the value of candidate prognostic factors (PFs) in predicting carpal tunnel release surgery. PATIENTS AND METHODS: This is a retrospective cohort study set in the Clinical Practice Research Datalink. Patients ≥18 years presenting with an incident episode of CTS were identified between 1989 and 2013. Candidate PF's defined in coded electronic patient records were identified following literature review and consultation with clinicians. Time to first carpal tunnel release surgery was the primary end point. A manual backward stepwise selection procedure was used to obtain an optimal prediction model, which included all the significant PFs. RESULTS: In total, 91,412 patients were included in the cohort. The following PFs were included in an optimal model (C-statistic: 0.588 [95% CI 0.584-0.592]) for predicting surgical intervention: geographical region; deprivation status; age hazard ratio (HR 1.02 per year, 95% CI 1.01-1.02); obesity (HR 1.23, 95% CI 1.19-1.27); alcohol drinker (HR 1.05, 95% CI 1.00-1.10); smoker (HR 1.06, 95% 1.03-1.10); inflammatory condition (HR 1.13, 95% CI 0.98-1.29); neck condition (HR 1.13, 95% CI 1.03-1.23); and multisite pain (HR 1.10, 95% CI 1.05-1.15). Although not included in the multivariable model, pregnancy (if gender female) within 1 year of the index consultation, reduced the risk of surgery (HR 0.24, 95% CI 0.21-0.28). CONCLUSION: This study shows that patients who are older and who have comorbidities including other pain conditions are more likely to have surgery, whereas patients presenting with CTS during or within a year of pregnancy are less likely to have surgery. This information can help to inform clinicians and patients about the likely outcome of treatment and to be aware of which patients may be less responsive to primary care interventions.

Trends in the prevalence, incidence and surgical management of carpal tunnel syndrome between 1993 and 2013: an observational analysis of UK primary care records.

OBJECTIVES: To describe the prevalence, incidence and surgical management of carpal tunnel syndrome (CTS), between 1993 and 2013, as recorded in the Clinical Practice Research Datalink (CPRD). DESIGN: We completed a series of cross-sectional epidemiological analyses to observe trends over time. SETTING: Primary care data collected between 1993 and 2013, stored in the CPRD. POPULATION: Individuals aged ≥18 years were selected. Prevalent and incident episodes of CTS and episodes of surgical intervention were identified using a list of preidentified Read codes. ANALYSIS: We defined incident episodes as those with no preceding diagnostic code for CTS in the past 2 years of data. Episodes of surgery were expressed as a percentage of the prevalent population during the same calendar year. Joinpoint regression was used to determine significant changes in the underlying trend. RESULTS: The prevalence of CTS increased over the study period, with a particular incline between 2000 and 2004 (annual percentage change 7.81). The female-to-male prevalence ratio reduced over time from 2.74 in 1993 to 1.93 in 2013. The median age of females and males with CTS were noted to increase from 49 and 53 years, respectively in 1993 to 54 and 59 years, respectively in 2013. Incidence was also noted to increase over time. After an initial increase between 1993 and 2007, the percentage of prevalent patients with a coded surgical episode began to decrease after 2007 to 27.41% in 2013 (annual percentage change -1.7). CONCLUSION: This study has demonstrated that the prevalence and incidence of CTS increased over the study period between 1993 and 2013. Rates of surgery for CTS also increased over the study period; however after 2007, the per cent of patients receiving surgery showed a statistically significant decline back to the rate seen in 2004.

Interrater reliability of algometry in measuring pressure pain thresholds in healthy humans, using multiple raters.

OBJECTIVE: To evaluate interrater reliability using 5 newly trained observers in the assessment of pressure pain threshold (PPT) using a fixed-angle algometer. METHODS: The study design comprised 2 phases. Phase 1: 5 undergraduate physical therapists were trained in algometry at a predefined angle, at a rate of 5 Newtons (N)/s, to the first dorsal interosseous muscle. Each observer then underwent a competency test of the application speed. The aim was to achieve repeated applications at 5 N/s without visual feedback from the algometer. Phase 2: the 5 observers measured PPT of 13 healthy volunteers, at the first dorsal interosseous muscle. The sequence of observer measurements for each participant was randomized. Mean PPT values for each observer were analyzed using repeated measures analysis of variance, intraclass correlation coefficient (ICC2,1), and standard error of measurement, with 95% confidence intervals (CIs). RESULTS: No significant differences between observers' mean values were found (P=0.094), suggesting no bias. The ICC was 0.91 (95% CI 0.82, 0.97). The standard error of measurement value was 6.27 N/cm (95% CI 5.35, 7.59). Differences in PPT measurements of more than 17.39 N/cm (1.77 kg/cm) are likely to exceed the magnitude of measurement error, and could be used to indicate true change. This margin of error is, however, somewhat larger than a previously proposed minimum clinically important difference in PPT of 14.71 N/cm (1.5 kg/cm). DISCUSSION: This study provides new evidence that trained observers can apply an algometer at a consistent rate and provide highly reliable measures of PPT in healthy humans, when PPT is calculated as the mean of 3 trials.

Management of shoulder pain by UK general practitioners (GPs): a national survey.

OBJECTIVES: Studies in Canada, the USA and Australia suggested low confidence among general practitioners (GPs) in diagnosing and managing shoulder pain, with frequent use of investigations. There are no comparable studies in the UK; our objective was to describe the diagnosis and management of shoulder pain by GPs in the UK. METHODS: A national survey of a random sample of 5000 UK GPs collected data on shoulder pain diagnosis and management using two clinical vignettes that described primary care presentations with rotator cuff tendinopathy (RCT) and adhesive capsulitis (AdhC). RESULTS: Seven hundred and fourteen (14.7%) responses were received. 56% and 83% of GPs were confident in their diagnosis of RCT and AdhC, respectively, and a wide range of investigations and management options were reported. For the RCT presentation, plain radiographs of the shoulder were most common (60%), followed by blood tests (42%) and ultrasound scans (USS) (38%). 19% of those who recommended a radiograph and 76% of those who recommended a USS did so 'to confirm the diagnosis'. For the AdhC presentation, the most common investigations were blood tests (60%), plain shoulder radiographs (58%) and USS (31%). More than two-thirds of those recommending a USS did so 'to confirm the diagnosis'. The most commonly recommended treatment for both presentations was physiotherapy (RCT 77%, AdhC 71%) followed by non-steroidal anti-inflammatory drugs (RCT 58%, AdhC 74%). 17% opted to refer the RCT to secondary care (most often musculoskeletal interface service), compared with 31% for the AdhC. CONCLUSIONS: This survey of GPs in the UK highlights reliance on radiographs and blood tests in the management of common shoulder pain presentations. GPs report referring more than 7 out of 10 patients with RCT and AdhC to physiotherapists. These findings need to be viewed in the context of low response to the survey and, therefore, potential non-response bias.

An Economic Evaluation of TENS in Addition to Usual Primary Care Management for the Treatment of Tennis Elbow: Results from the TATE Randomized Controlled Trial.

BACKGROUND: The TATE trial was a multicentre pragmatic randomized controlled trial of supplementing primary care management (PCM)-consisting of a GP consultation followed by information and advice on exercises-with transcutaneous electrical nerve stimulation (TENS), to reduce pain intensity in patients with tennis elbow. This paper reports the health economic evaluation. METHODS AND FINDINGS: Adults with new diagnosis of tennis elbow were recruited from 38 general practices in the UK, and randomly allocated to PCM (n = 120) or PCM plus TENS (n = 121). Outcomes included reduction in pain intensity and quality-adjusted-life-years (QALYs) based on the EQ5D and SF6D. Two economic perspectives were evaluated: (i) healthcare-inclusive of NHS and private health costs for the tennis elbow; (ii) societal-healthcare costs plus productivity losses through work absenteeism. Mean outcome and cost differences between the groups were evaluated using a multiple imputed dataset as the base case evaluation, with uncertainty represented in cost-effectiveness planes and through probabilistic cost-effectiveness acceptability curves). Incremental healthcare cost was £33 (95%CI -40, 106) and societal cost £65 (95%CI -307, 176) for PCM plus TENS. Mean differences in outcome were: 0.11 (95%CI -0.13, 0.35) for change in pain (0-10 pain scale); -0.015 (95%CI -0.058, 0.029) for QALYEQ5D; 0.007 (95%CI -0.022, 0.035) for QALYSF6D (higher score differences denote greater benefit for PCM plus TENS). The ICER (incremental cost effectiveness ratio) for the main evaluation of mean difference in societal cost (£) relative to mean difference in pain outcome was -582 (95%CI -8666, 8113). However, incremental ICERs show differences in cost-effectiveness of additional TENS, according to the outcome being evaluated. CONCLUSION: Our findings do not provide evidence for or against the cost-effectiveness of TENS as an adjunct to primary care management of tennis elbow.

Gender differences in pressure pain threshold in healthy humans.

UNLABELLED: AIMS OF INVESTIGATION: To quantify the magnitude of putative gender differences in experimental pressure pain threshold (PPT), and to establish the relevance of repeated measurements to any such differences. METHODS: Two separate studies were undertaken. A pressure algometer was used in both studies to assess PPT in the first dorsal interosseous muscle. Force was increased at a rate of 5 N /s. In study 1, two measurements were taken from 240 healthy volunteers (120 males, 120 females; mean age 25 years) giving a power for statistical analysis of beta=0.80 at alpha=0.01. In study two, 30 subjects (15 males, 15 females mean age 28 years) were randomly selected from study one. Fourteen repeated PPT measurements were recorded at seven, 10 min intervals. Mean PPT data for gender groups, from both studies, were analysed using analysis of covariance with repeated measures, and age as the covariate. RESULTS: The mean PPT for each of the two measurements in study one showed a difference between gender of 12.2 N (f=30.5 N, m=42.7 N) and 12.8 N (f=29.5 N, m=42.3 N), respectively, representing a difference of 28% with females exhibiting a lower threshold. In study two, the mean difference calculated from 14 PPT repeated measurements over a 1h period was comparable to that in study one at 12.3N (range 10.4-14.4 N) again females exhibited the lower threshold. The differences in mean PPT values between gender were found to be significant in both study one, at (P<0.0005, F=37.8, df=1) and study two (P=0.01, F=7.6, df=1). No significant differences were found in either study with repeated measurement (P=0.892 and P=0.280), or on the interaction of gender and repeated measurement after controlling for age (P=0.36 and P=0.62). CONCLUSION: Healthy females exhibited significantly lower mean PPTs in the first dorsal interosseous muscle than males, which was maintained for fourteen repeated measures within a 1 h period. This difference is likely to be above clinically relevant levels of change, and it has clear implications for the use of different gender subjects in laboratory based experimental designs utilising PPT as an outcome measure.

Effects of TENS frequency, intensity and stimulation site parameter manipulation on pressure pain thresholds in healthy human subjects.

UNLABELLED: This study evaluated the effects of varying frequency, intensity and stimulation site, of transcutaneous electrical nerve stimulation (TENS) in an experimental model of pain. In a double-blind design 240 volunteers were randomised to one of six experimental TENS groups, a sham TENS or control (n=30 per group; gender balanced). Two TENS frequencies (110 or 4 Hz) and two intensities (strong but comfortable or highest tolerable) at a fixed pulse duration (200 micros) were applied at three sites relative to the measurement site (segmentally, extrasegmentally or a combination of these), for 30 min. Pressure pain thresholds (PPT) were measured using a pressure algometer, in the first dorsal interosseous muscle, every 10 min, during stimulation and for a further 30 min. The high frequency, high intensity segmental, and combined stimulation groups, showed rapid onset and significant hypoalgesic effects. This effect was sustained for 20 min post-stimulation in the high frequency segmental group. All other TENS intervention groups showed hypoalgesic responses similar to the sham TENS group, and none of these groups reached a clinically significant hypoalgesic level. CONCLUSIONS: The role of TENS frequency, intensity and site are pivotal to achieving optimal hypoalgesic effects, during and after stimulation. Clinical applications of these parameter combinations require further investigations.

Sensory stimulation (TENS): effects of parameter manipulation on mechanical pain thresholds in healthy human subjects.

Transcutaneous electrical nerve stimulation (TENS) is a popular form of electrostimulation. Despite an extensive research base, there remains no consensus regarding the parameter selection required to achieve maximal hypoalgesic effects. The aim of this double blind, sham-controlled study was to investigate the relative hypoalgesic effects of different TENS parameters (frequency, intensity and stimulation site) upon experimentally induced mechanical pain. Two hundred and forty participants were recruited in order to provide statistical analysis with 80% power at alpha = 0.05. Subjects were randomised to one of the six TENS groups, a control, and a sham TENS group (n = 30, 15 males, 15 females, per group). TENS groups differed in their combinations of stimulation; frequency (4 or 110 Hz), intensity ('to tolerance' or 'strong but comfortable') and stimulation site (segmental--over the distribution of the radial nerve or, extrasegmental--over acupuncture point 'gall bladder 34', or a combination of both segmental and extrasegmental). Pulse duration was fixed at 200 micros. Stimulation was delivered for 30 min and subjects were then monitored for a further 30 min. Mechanical pain threshold (MPT) was measured using a pressure algometer and taken from the first dorsal interosseous muscle of the dominant hand, ipsilateral to the stimulation site. MPT measures were taken, at baseline, and at 10-min intervals for 60 min. Difference scores were analysed using repeated measures and one-way ANOVA and relevant post hoc tests. Low frequency, high intensity, extrasegmental stimulation produced a rapid onset hypoalgesic effect, which increased during the stimulation period (P < 0.0005 control and sham) and was sustained for 30 min post-stimulation (P < 0.0005(control), P = 0.024(sham)). Whilst high frequency, 'strong but comfortable' intensity, segmental stimulation produced comparable hypoalgesic levels during stimulation, this effect was not sustained post-stimulation. Stimulation at a combination of the two sites did not produce any greater hypoalgesic effects. These results may have implications for the clinical use of sensory stimulation.

Alternating-frequency TENS effects on experimental pain in healthy human participants: a randomized placebo-controlled trial.

BACKGROUND: Transcutaneous electrical nerve stimulation (TENS) is a modality commonly used in pain management. OBJECTIVES: This study investigated the hypoalgesic effects of alternating-frequency TENS (4 Hz for 3 s/110 Hz for 3 s) on pressure pain threshold (PPT). METHODS: Two-hundred and eight healthy, pain-free volunteers (19 to 59 y old; 104 males, 104 females) were randomized to 8 groups: 6 active TENS groups, placebo, and control (n=26 per group). Parameter combinations were such that alternating-frequency TENS was combined with different levels of intensity "low" (strong but comfortable) or "high" (strong and uncomfortable but not painful). TENS was administered either at the forearm (segmental stimulation), at the ipsilateral leg (extrasegmental stimulation), or at both sites (dual-site stimulation) for 30 minutes and monitored for 30 further minutes. PPT measurements were taken bilaterally from the mid-point of first dorsal interosseous muscle, by an independent blinded rater, at baseline and at 6 subsequent 10-minute intervals. Square-root transformed data were analyzed using repeated measures analysis of covariance (baseline values and sex as covariates). RESULTS: Alternating-frequency TENS groups did not achieve significant hypoalgesic effects compared with placebo or control (P>0.05). The largest increase in PPT (from baseline) was 76.6 kPa with low-intensity segmental alternating frequency TENS at the 20-minute stimulation time point. This change from baseline is below a difference of 100 kPa that is considered to be a clinically meaningful change in hypoalgesia. DISCUSSION: The alternating-frequency setting does not result in large hypoalgesic effects such as those previously reported using fixed-frequency TENS.

Transcutaneous electrical nerve stimulation as adjunct to primary care management for tennis elbow: pragmatic randomised controlled trial (TATE trial).

OBJECTIVE: To investigate the effectiveness of supplementing information and advice on analgesia and exercise from a general practitioner with transcutaneous electrical nerve stimulation (TENS) as a non-drug form of analgesia to reduce pain intensity in patients with tennis elbow. DESIGN: Pragmatic randomised controlled trial in primary care. SETTING AND: 38 general practices in the West Midlands, UK. PARTICIPANTS: 241 adults consulting with a first or new (no consultation in previous six months) clinical diagnosis of tennis elbow. INTERVENTIONS: Participants were randomly allocated to either primary care management alone, consisting of a consultation with a general practitioner followed by information and advice on exercises, or primary care management plus TENS to be used once a day for 45 minutes over six weeks (or until symptom resolution) for pain relief. OUTCOME MEASURES: The primary outcome was self reported intensity of elbow pain (0-10 rating scale) at six weeks. Primary and secondary outcomes were measured at baseline and at six weeks, six months, and 12 months by postal questionnaire. Analysis was by intention to treat. RESULTS: 121 participants were randomised to primary care management plus TENS and 120 to primary care management only (first episode, n=197 (82%); duration <1-3 months, n=138 (57%)). Adherence to exercise and TENS recommendations reported at six weeks was low; only 42 participants in the primary care management plus TENS group met a priori defined adherence criteria. Both intervention groups showed large improvements in pain and secondary outcomes, especially during the first six weeks of follow-up. However, no clinically or statistically significant differences were seen between groups at any follow-up timepoint. At the primary endpoint (six weeks), the between group difference in improvement of pain was -0.33 (95% confidence interval -0.96 to 0.31; P=0.31) in favour of the primary care management only group, with adjustment for age, sex, and baseline pain score. CONCLUSIONS: This trial does not provide evidence for additional benefit of TENS as an adjunct to primary care management of tennis elbow. Poor adherence to interventions is evidence of the challenges of implementing self management treatment strategies in primary care. TRIAL REGISTRATION: Current Controlled Trials ISRCTN87141084.

Effects of interferential therapy parameter combinations upon experimentally induced pain in pain-free participants: a randomized controlled trial.

BACKGROUND: Little evidence exists regarding parameter selection for hypoalgesia using interferential therapy (IFT). OBJECTIVE: This study investigated segmental and extrasegmental hypoalgesic effects of different IFT parameter combinations upon experimentally induced pressure pain threshold (PPT) in pain-free volunteers. DESIGN: The participants were randomly assigned to 6 groups: control, placebo, bipolar constant amplitude modulation frequency (AMF), bipolar sweep AMF, quadripolar constant AMF, and quadripolar sweep AMF. SETTING: The study was conducted in a university laboratory. PARTICIPANTS: One hundred eighty adults who were healthy and pain-free participated in the study. INTERVENTION: Interferential therapy was delivered to all groups at high, to-tolerance intensity and at high AMF. Stimulation to the dominant forearm was delivered for 30 minutes, with monitoring for a further 30 minutes. MEASUREMENTS: Pain pressure threshold was measured at the area of first dorsal interosseous muscle of the dominant and nondominant hands (segmental measurements) and over the tibialis anterior muscle (extrasegmental measurement) at baseline and at 10-minute intervals using a pressure algometer. Square root transformed PPT data were analyzed using repeated-measures analysis of variance. RESULTS: There was a significant change in PPT over time, but no significant between-subjects difference in segmental or extrasegmental PPT between any of the IFT groups and the placebo or control group. Thus, IFT delivered in any of these parameter combinations did not significantly affect the PPT of pain-free participants compared with the control or placebo group. LIMITATIONS: Success of blinding was not evaluated. CONCLUSIONS: This study showed that IFT delivered at high, to-tolerance intensity and high AMF does not produce significant segmental and extrasegmental hypoalgesic effects on PPT in participants who were healthy compared with a control or placebo group. Further research is warranted to investigate the hypoalgesic effect of different IFT parameter combinations and to explain its possible mechanism of action.

Management of tennis elbow.

CLINICAL QUESTION: What is the best treatment for tennis elbow? RESULTS: Despite a wealth of research, there is no true consensus on the most efficacious management of tennis elbow especially for effective long-term outcomes. Corticosteroid injections do show large pain-relieving effects in the short term but are associated with risks of adverse events and long-term reoccurrence. Advice with a "wait and see" approach is recommended as the first-line treatment in primary care for most cases. In the medium term physiotherapy and or low-level laser therapy may be effective. IMPLEMENTATION: Rule out alternative diagnosis. Onward referral may be indicated if the condition does not resolve after 12 months.