Effect of magnetic vs sham-magnetic insoles on nonspecific foot pain in the workplace: a randomized, double-blind, placebo-controlled trial

Effects of a Concentric Rare-Earth Magnet on Menstrual Cycle Pain: A Parallel Group Randomized Pilot Study

Background Based on prior reports of the use of magnets to treat pain, our goal was to determine if a concentric rare-earth alternating-pole magnet reduced period pain versus a sham-magnet.  Methods Participants were females (N=36, 18 to 35 years) who regularly experienced menstrual period pain ≥ six on the numeric pain rating scale (NPRS) of 0-10. Subjects were excluded if they took pain medication on the study day or had implanted pacemakers/metallic devices or secondary dysmenorrhea. Participants were randomized to wear a concentric neodymium-iron boron active-magnet (surface-field of 0.4 Tesla) or a sham magnet. The participant and investigator applying the device were blinded to the device used. The device was placed at the abdominal location of the reported greatest pain for 40-minutes, during which time the subject was able to conduct the normal activity. Pain scores were reported prior to device wearing and afterward. Participants with post-treatment NPRS ratings reduced by ≥ 35% from their pretreatment pain ratings were scored as having reduced pain; reductions < 35% were scored as no meaningful pain change. The threshold of 35% was chosen based on a survey of 10 women as to the level of pain reduction they viewed as meaningful to them. Of the 36 women in this pilot study, 19 wore an active-magnet and 17 wore a sham-magnet. Analyses were based on chi-square and Mann-Whitney statistical tests. Results  Pre-treatment pain scores (mean ± SD) were similar for both groups. Magnet-vs-sham pre-treatment scores were, respectively, 7.16 ± 0.85 vs. 6.94 ± 1.20 (p=0.330). Corresponding median values for the magnet (N=19) and sham (N=17) groups respectively were seven pre-treatment and four post-treatment vs. six pre-treatment and six post-treatment. Post-treatment scores for magnet treated subjects (4.16 ± 2.20) were significantly less (p=0.027) than for sham-treated (5.53 ± 1.50). Of the 19 who wore a magnet, 11 experienced meaningful pain-reduction, and eight did not. Of the 17 who wore a sham, three experienced meaningful pain-reduction, and 14 did not. Magnet and sham wearing responses were statistically significant via chi-square analysis (chi-square=6.12, p=0.013). Percentage reduction in pain score was 41.8% ± 31.1% for magnet-treated vs. 20.8% ± 16.1%, for sham-treated (p<0.05). Conclusions Results suggest that short-term wearing of the magnet herein investigated, produces a meaningful menstrual-pain reduction in some women. Thus, further expanded research seems warranted to determine if longer wearing times result in even greater pain reductions.

The effect of insoles on foot pain and daily activities

BACKGROUND

Foot pain decreases individuals' ability to perform daily activities. Insoles are often prescribed to reduce the pain which, in turn, may promote return to normal activities.

OBJECTIVES

To evaluate the effects of insoles on foot pain and daily activities, and to investigate the relationship between individuals' satisfaction with insoles and actual use of them.

STUDY DESIGN

A 4-week pre-post intervention follow-up.

METHODS

Brief Pain Inventory, International Physical Activity Questionnaire and Lower Extremities Functional Status were used as outcome measures. Client Satisfaction with Device was used in the follow-up.

RESULTS

A total of 67 participants answered the questionnaires (81% women). Overall, a reduction in Pain Severity (p = 0.002) and Pain Interference (p = 0.008) was shown. Secondary analyses revealed a significant effect only in women. No changes in daily activities (Walking, p = 0.867; Total Physical Activity, p = 0.842; Lower Extremities Functional Status, p = 0.939) could be seen. There was no relation between Client Satisfaction with Device measures and duration of insole use. A difference in sex was shown; women scored higher than men on Pain Severity.

CONCLUSION

Insoles reduce pain and pain interference with daily activities for women with foot pain. Satisfaction with the insoles is not a predictor of actual insole use. The effect of insoles on activity performance needs further study.

CLINICAL RELEVANCE

This study provides evidence for prescribing insoles to people with foot pain. Nonetheless, insoles are not enough to increase their physical activity level in the short term. Satisfaction with insoles and duration of use are not correlated and cannot be inferred from each other.

[Medical relevance of magnetic fields in pain therapy]

BACKGROUND

Magnetic and electromagnetic fields have been accepted as real physical entities in medicine and are believed to achieve pain relief. Magnetic field therapy has been acknowledged as a non-invasive, safe and simple method for treatment of the site of injury, source of pain or inflammation, or other types of illnesses and pathologies. However, a consensus regarding the statistical relevance of the effects has not been established.

MATERIALS AND METHODS

A detailed literature research was performed and the results were evaluated. Inclusion criteria were that the studies had to be randomized, double-blind and placebo-controlled, and no additional forms of treatment other than magnetic effects were allowed to be used.

RESULTS

The evaluation of 17 studies with static magnetic fields showed on average no significant difference in pain relief between the group treated with magnetic fields and the placebo group. All studies using magnetic fields showed that forms of treatment conducted over a period of 30 min and at intervals of 1 week have no effects. In 10 studies with dynamic magnetic fields different effects were registered, which ranged from no effect to significant differences regarding pain relief between the treated and the control groups.

CONCLUSIONS

Static magnetic fields are ineffective with respect to pain therapy. Dynamic magnetic fields show diverse effects. Hence, this therapy should be researched in depth.

The effects of manual treatment on rounded-shoulder posture, and associated muscle strength

SUMMARY

A relationship between pectoralis minor muscle tightness and rounded shoulder posture (RSP) has been suggested, but evidence demonstrating that treatment aimed at the pectoralis minor affects posture or muscle function such as lower trapezius strength (LTS) remains lacking. In this randomized, blinded, controlled study of the 56 shoulders of 28 healthy participants, the experimental treatment consisting of pectoralis minor soft tissue mobilization (STM) and self-stretching significantly reduced RSP compared to the pre-treatment baseline (Friedman test, p<.001) and the control treatment of placebo touch and pectoralis major self-stretching (Mann-Whitney U-test, p<.01). RSP remained significantly reduced 2 weeks after the single treatment. Both control and experimental treatments resulted in increased LTS (Friedman test, p<.01) with no significant difference in LTS noted between treatments (p>.05). This study demonstrated that STM and self-stretching of the pectoralis minor can significantly reduce RSP.

Static magnetic field therapy: dosimetry considerations

The widespread use of static magnetic field (SMF) therapy as a self-care physical intervention has led to the conduct of numerous randomized controlled trials (RCTs). A recent systematic review of SMF trials for pain reduction concluded that the evidence does not support the use of permanent magnets for pain relief. We argue that this conclusion is unwarranted if the SMF dosage was inadequate or inappropriate for the clinical condition treated. The purpose of this communication is to (1) provide a rationale and an explanation for each of 10 essential SMF dosing parameters that should be considered when conducting trials of SMF therapy, and (2) advocate for the conduct of Phase I studies to optimize SMF dosimetry for each condition prior to implementing a large-scale RCT. A previous critical review of SMF dosimetry in 56 clinical studies found that reporting SMF dosages in a majority of those studies was of such poor quality that the magnetic field exposure at the target tissue could not be characterized. Without knowing what magnetic field actually reached the target, it is impossible to judge dosage adequacy. In order to quantify SMF exposure at the site of pathology (target tissue/s), that site must be clearly named; the distance of the permanent magnet surface from the target must be delineated; the physical parameters of the applied permanent magnet must be described; and the dosing regimen must be precisely reported. If the SMF dosimetry is inadequate, any inferences drawn from reported negative findings are questionable.

Static magnetic field therapy: a critical review of treatment parameters

Static magnetic field (SMF) therapy, applied via a permanent magnet attached to the skin, is used by people worldwide for self-care. Despite a lack of established SMF dosage and treatment regimens, multiple studies are conducted to evaluate SMF therapy effectiveness. Our objectives in conducting this review are to:(i) summarize SMF research conducted in humans; (ii) critically evaluate reporting quality of SMF dosages and treatment parameters and (iii) propose a set of criteria for reporting SMF treatment parameters in future clinical trials. We searched 27 electronic databases and reference lists. Only English language human studies were included. Excluded were studies of electromagnetic fields, transcranial magnetic stimulation, magnets placed on acupuncture points, animal studies, abstracts, posters and editorials. Data were extracted on clinical indication, study design and 10 essential SMF parameters. Three reviewers assessed quality of reporting and calculated a quality assessment score for each of the 10 treatment parameters. Fifty-six studies were reviewed, 42 conducted in patient populations and 14 in healthy volunteers. The SMF treatment parameters most often and most completely described were site of application, magnet support device and frequency and duration of application. Least often and least completely described were characteristics of the SMF: magnet dimensions, measured field strength and estimated distance of the magnet from the target tissue. Thirty-four (61%) of studies failed to provide enough detail about SMF dosage to permit protocol replication by other investigators. Our findings highlight the need to optimize SMF dosing parameters for individual clinical conditions before proceeding to a full-scale clinical trial.

Static magnets for reducing pain: systematic review and meta-analysis of randomized trials

BACKGROUND

Static magnets are marketed with claims of effectiveness for reducing pain, although evidence of scientific principles or biological mechanisms to support such claims is limited. We performed a systematic review and meta-analysis to assess the clinical evidence from randomized trials of static magnets for treating pain.

METHODS

Systematic literature searches were conducted from inception to March 2007 for the following data sources: MEDLINE, EMBASE, AMED (Allied and Complementary Medicine Database), CINAHL, Scopus, the Cochrane Library and the UK National Research Register. All randomized clinical trials of static magnets for treating pain from any cause were considered. Trials were included only if they involved a placebo control or a weak magnet as the control, with pain as an outcome measure. The mean change in pain, as measured on a 100-mm visual analogue scale, was defined as the primary outcome and was used to assess the difference between static magnets and placebo.

RESULTS

Twenty-nine potentially relevant trials were identified. Nine randomized placebo-controlled trials assessing pain with a visual analogue scale were included in the main meta-analysis; analysis of these trials suggested no significant difference in pain reduction (weighted mean difference [on a 100-mm visual analogue scale] 2.1 mm, 95% confidence interval -1.8 to 5.9 mm, p = 0.29). This result was corroborated by sensitivity analyses excluding trials of acute effects and conditions other than musculoskeletal conditions. Analysis of trials that assessed pain with different scales suggested significant heterogeneity among the trials, which means that pooling these data is unreliable.

INTERPRETATION

The evidence does not support the use of static magnets for pain relief, and therefore magnets cannot be recommended as an effective treatment. For osteoarthritis, the evidence is insufficient to exclude a clinically important benefit, which creates an opportunity for further investigation.