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.

Acupuncture as an adjunct to exercise based physiotherapy for osteoarthritis of the knee: randomised controlled trial Nadine E Foster, senior lecturer in therapies (pain management), 1 Interventions Advice and exercise (n=116), advice and exercise plus true acupuncture (n=117), and advice and exercise plus non-penetrating acupuncture (n=119). Main outcome measures The primary outcome was change in scores on the Western Ontario and McMaster Universities osteoarthritis index pain subscale at six months. Secondary outcomes included function, pain intensity, and unpleasantness of pain at two weeks, six weeks, six months, and 12 months. Results Follow-up rate at six months was 94%. The mean (SD) baseline pain score was 9.2 (3.8). At six months mean reductions in pain were 2.28 (3.8) for advice and exercise, 2.32 (3.6) for advice and exercise plus true acupuncture, and 2.53 (4.2) for advice and exercise plus non-penetrating acupuncture. Mean differences in change scores between advice and exercise alone and each acupuncture group were 0.08 (95% confidence interval −1.0 to 0.9) for advice and exercise plus true acupuncture and 0.25 (−0.8 to 1.3) for advice and exercise plus non-penetrating acupuncture. Similar nonsignificant differences were seen at other follow-up points. Compared with advice and exercise alone there were small, statistically significant improvements in pain intensity and unpleasantness at two and six weeks for true acupuncture and at all follow-up points for nonpenetrating acupuncture. Conclusion The addition of acupuncture to a course of advice and exercise for osteoarthritis of the knee delivered by physiotherapists provided no additional improvement in pain scores. Small benefits in pain intensity and unpleasantness were observed in both acupuncture groups, making it unlikely that this was due to acupuncture needling effects.Trial registration Current Controlled Trials ISRCTN88597683.

Acupuncture that meets criteria for adequate treatment is significantly superior to sham acupuncture and to no additional intervention in improving pain and function in patients with chronic knee pain. Due to the heterogeneity in the results, however, further research is required to confirm these findings and provide more information on long-term effects.

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.

Many different styles of acupuncture practice exist, and lack of agreement on the optimal acupuncture treatment for any particular condition may mean that some patients do not receive the best treatment. This uncertainty also makes the negative results of sham controlled trials difficult to interpret. Unless we can be sure that both adequate acupuncture and an inactive sham were used in a particular trial, then that trial should not be interpreted as dismissing acupuncture for that condition. Acupuncture practice clearly involves much more than needling procedures, but there is a strong argument for elucidating the role of those needling procedure first. The components of acupuncture needling procedures have been described in the STRICTA document, but it is also clear that the patient's perception of needling is relevant for the outcome of treatment. We therefore recommend the concept of ‘dose’ of acupuncture needling, which should include both the stimulus given to the patient, and certain aspects of the patient's perceptions and response that are known to be linked to the subsequent therapeutic response. We propose the following definition of dose: the physical procedures applied in each session, using one or more needles, taking account of the patient's resulting perception (sensory, affective and cognitive) and other responses (including motor). The dose may be affected by the state of the patient (eg nervous, immune and endocrine systems); different doses may be required for different conditions. The constituents of an adequate dose can be established initially by clinical opinion and subsequently by empirical evidence from experimental studies, which may be either clinical or basic research studies. Systematic reviews which do not consider the adequacy of the acupuncture treatment may have unreliable conclusions. Out of 47 recent systematic reviews, only six have applied some criteria for adequacy. Five used a rating system or conducted a subgroup analysis, and one excluded studies from the analysis altogether if they did not meet criteria for adequacy. Research into what constitutes an adequate dose of acupuncture has long been neglected and is now urgent. Clinical studies that compare the effects of different treatment protocols are probably the most reliable source of evidence, and may also demonstrate a dose-response relationship.

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.

The effect of acupuncture upon experimentally induced delayed onset muscle soreness (DOMS) was assessed in a placebo-controlled study under blinded conditions. Volunteers (n = 48; 24 M & 24 F) were randomly allocated to one of four groups: control (20 min rest), placebo (minimal needling at non-acupuncture points), treatment group 1 (acupuncture at classic acupuncture points) and treatment group 2 (acupuncture at 'tender' points). DOMS was induced in the elbow flexors of the non-dominant arm using a standardized eccentric exercise regime. Measurements of elbow range of movement (flexion, extension, relaxed angle), and pain as well as visual analogue scores (VAS), tenderness (using a pressure algometer) were employed as indices of treatment efficacy. Measurements of elbow range of movement and tenderness were made prior to DOMS induction on the first day, and repeated pre- and post-treatment on subsequent days; pain was assessed using visual analogue scales post-induction and post-treatment on the first day, and pre- and post-treatment thereafter. For all conditions, subjects rested supine for a period of 20 min, during which treatment was delivered according to group allocation. Repeated measures and one-way analysis of variance (ANOVA) demonstrated no significant interactive (AB) effects, except for visual analogue scores (P = 0.0483); one factor ANOVA on the second day of the experiment (pre-treatment) indicated significant differences between the control and all other groups. However, such differences were not found on any other day of the experiment. It is concluded that acupuncture has little effect upon the cardinal signs and symptoms of DOMS, at least under the conditions of the current experiment.

Electroacupuncture is commonly used for pain relief. Despite an extensive evidence-base guiding the selection of stimulation parameters, little methodologically robust research exists regarding the level of intensity required to provide effective doses. This study investigated the hypoalgesic effects of two stimulation intensities compared to placebo on pressure pain thresholds (PPTs) in pain-free humans. Forty-eight acupuncture-naïve volunteers (mean age 23), stratified by gender, were screened for relevant contraindications and randomly allocated to four groups: control, placebo, high-intensity ("to tolerance but sub-noxious") or low-intensity ("strong but comfortable"). True or placebo electroacupuncture, using the Streitberger placebo needle, was administered to acupoints on dominant forearm (LI10, TH5) and ipsilateral leg (GB34, ST38). True needles (30 mm long, 0.3 mm diameter) were inserted 20-25 mm and "de-qi" was elicited from active groups, prior to administering 30 min of 4 Hz, 200 micros electroacupuncture. No electrical stimulation was performed on control and placebo groups, and placebo needles were used. After the intervention period, all needles were removed. Volunteers were monitored for 30 further minutes. Two PPT measurements were taken bilaterally from muscle bellies of first dorsal interosseous by an independent rater, at baseline and at six subsequent 10-min intervals. Square-root transformed data were analysed using repeated-measures ANOVA, with baseline data as covariate. The high-intensity group was significantly different from the placebo group for both measurement sites (p=.020, p=.033). The control group displayed stable PPT readings over time. No significant differences were observed between the placebo and control groups. These findings suggest that high-intensity levels may be important in optimal dose selection.