Influence of preferred versus prescribed exercise on pain in fibromyalgia

Effects of motor imagery using virtual reality on pain sensitivity and affect in healthy individuals: a prospective randomized crossover study

OBJECTIVE

Exercise induces a hypoalgesic response and improves affect. However, some individuals are unable to exercise for various reasons. Motor imagery, involving kinesthetic and visual imagery without physical movement, activates brain regions associated with these benefits and could be an alternative for those unable to exercise. Virtual reality also enhances motor imagery performance because of its illusion and embodiment. Therefore, we examined the effects of motor imagery combined with virtual reality on pain sensitivity and affect in healthy individuals.

DESIGN

Randomized crossover study.

SETTING

Laboratory.

SUBJECTS

Thirty-six participants (women: 18) were included.

METHODS

Each participant completed three 10-min experimental sessions, comprising actual exercise, motor imagery only, and motor imagery combined with virtual reality. Hypoalgesic responses and affective improvement were assessed using the pressure-pain threshold and the Positive and Negative Affect Schedule, respectively.

RESULTS

All interventions significantly increased the pressure-pain threshold at the thigh (P < .001). Motor imagery combined with virtual reality increased the pressure-pain threshold more than motor imagery alone, but the threshold was similar to that of actual exercise (both P ≥ .05). All interventions significantly decreased the negative affect of the Positive and Negative Affect Schedule (all P < .05).

CONCLUSIONS

Motor imagery combined with virtual reality exerted hypoalgesic and affective-improvement effects similar to those of actual exercise.

CLINICAL TRIALS REGISTRATION

The study was enrolled in the UMIN Clinical Trials Registry (registration number: UMIN000046095). The website for registration information is https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000052614.

Effectiveness of balneotherapy in reducing pain, disability, and depression in patients with Fibromyalgia syndrome: a systematic review with meta-analysis

Balneotherapy, using heated natural mineral waters at 36-38 °C, presents a comprehensive treatment approach for Fibromyalgia Syndrome (FMS). This study aims to assess the effect of balneotherapy in reducing pain intensity, disability, and depression in patients with FMS. We want to assess this effect at just four time-points: immediately at the end of the therapy, and at 1, 3, and 6 months of follow-up. Following PRISMA guidelines, we conducted an aggregate data meta-analysis, registered in PROSPERO CRD42023478206, searching PubMed Medline, Science Direct, CINAHL Complete, Scopus, and Web of Science until August 2023 for relevant randomized controlled trials (RCTs) that assess the effect of balneotherapy on pain intensity, disability, and depression in FMS patients. Methodological quality was assessed using the Cochrane methodology, and the pooled effect was calculated using Cohen's standardized mean difference (SMD) and its 95% confidence interval (95% CI) in a random-effects model. Sixteen RCTs were included in the meta-analysis. Balneotherapy is effective in reducing pain intensity (SMD - 1.67; 95% CI -2.18 to -1.16), disability (SMD - 1.1; 95% CI -1.46 to -0.7), and depression (SMD - 0.51; 95% CI -0.93 to -0.9) at the end of the intervention. This effect was maintained at 1, 3, and 6 months for pain intensity and disability. Balneotherapy improves both pain intensity and disability in patients with FMS, providing evidence that its positive effects are sustained for up to 6 months of follow-up. Nevertheless, it is important to note that the improvement in depression varies across different temporal phases.

Exercise-induced hypoalgesia in chronic neck pain: A narrative review

Chronic neck pain (CNP) is a worldwide health problem with several risk factors. One of the most widely used treatments for managing this condition is therapeutic exercise, which could generate a response called exercise-induced hypoalgesia (EIH). There is no consensus on the best exercise modality to induce hypoalgesia. Therefore, this review aims to analyze and synthesize the state-of-the-art about the hypoalgesic effect of exercise in subjects with CNP. We included articles on EIH and CNP in patients older than 18 years, with pain for more than three months, where the EIH response was measured. Articles that studied CNP associated with comorbidities or measured the response to treatments other than exercise were excluded. The studies reviewed reported variable results. Exercise in healthy subjects has been shown to reduce indicators of pain sensitivity; however, in people with chronic pain, the response is variable. Some investigations reported adverse effects with increased pain intensity and decreased pain sensitivity, others found no clinical response, and some even reported EIH with decreased pain and increased sensitivity. EIH is an identifiable, stimulable, and helpful therapeutic response in people with pain. More research is still needed on subjects with CNP to clarify the protocols and therapeutic variables that facilitate the EIH phenomenon. In addition, it is necessary to deepen the knowledge of the intrinsic and extrinsic factors that influence EIH in people with CNP.

Exercise Therapy for Chronic Neck Pain: Tailoring Person-Centred Approaches within Contemporary Management

Exercise therapy is considered the best evidence-based approach for managing chronic neck pain. However, the implementation of exercise therapy presents several challenges. Systematic reviews indicate that it has modest effectiveness, while clinical practice guidelines offer limited guidance on the exercise parameters required to optimise clinical outcomes. Moreover, recommendations often fail to differentiate between different types of neck pain. This article addresses the challenges associated with the prescription of exercise for chronic neck pain and provides recommendations for exercise therapy specific to chronic nociceptive, neuropathic, and nociplastic neck pain. The goal of this article is to facilitate the implementation of high-value evidence-based exercise therapy for these distinct types of chronic neck pain with the aim to improve its outcomes and to reduce the related individual and societal burdens.

The effectiveness of aerobic versus strengthening exercise therapy in individuals with chronic whiplash-associated disorder: a randomised single case experimental design study

PURPOSE

Recent RCTs and meta-analyses compare the effectiveness of different types of exercise for chronic whiplash associated disorder (WAD). This study aimed to verify whether the results of these studies translate to statistically significant and clinically meaningful effects in individual participants.

MATERIALS AND METHODS

A series of replicated randomised single case experimental design studies (SCEDs) with A-B design (A: baseline, B: intervention). Eight participants with chronic WAD (8 female, mean [SD] age 47 [10] years) were randomised into one of four baseline durations (5, 8, 11, and 14 days) and to one of two eight-week exercise interventions (aerobic or strengthening). Daily measures of pain intensity, bothersomeness, and interference were collected during the baseline phase and the intervention phase.

RESULTS

Visual analyses indicated that three participants in the aerobic exercise group meaningfully improved. No improvements were found in the strengthening group. Effect sizes favoured the aerobic exercise group, yet randomisation tests of pooled effects did not show a difference in between-intervention effectiveness.

CONCLUSION

Contrary to our expectations, three out of four participants were nearly pain-free at the end of the aerobic exercise intervention, whereas none of the participants in the strengthening group improved meaningfully. This suggests that aerobic exercise may be favourable for WAD.Implications for RehabilitationOur results suggest that aerobic exercises are favourable over strengthening exercises and may be the preferred option for patients with chronic WAD.We found substantial variability in self-reported outcomes within participants, clinicians should be aware of this in the judgement of treatment effectiveness.

Modulation of pain perceptions following treadmill running with different intensities in females

We aimed to compare the effects of three intensities of treadmill running on exercise-induced hypoalgesia (EIH) in healthy individuals. We anticipated that the primary and secondary changes in pain perception and modulation may differ between running intensities. Sixty-six women were randomly assigned to one of three treadmill running intensities for 35 min: 40% reserved heart rate (HRR), 55% HRR, or 70% HRR. The effects of EIH were assessed using pressure pain thresholds (PPT) and tolerance thresholds (PPTol). We measured conditional pain modulation (CPM). Compared with baseline, PPT and PPTol significantly increased in all groups during running and at the 5-10-min follow-up. The PPT and PPTol changes in the moderate- and low-intensity groups were significantly higher than those in the high-intensity group during running and 24 h after running, while the CPM responses of the high-intensity group were significantly reduced at the 24-h follow-up. Moderate- and low-intensity running may elicit significant primary and secondary (persisting over 24 h) EIH effects and increase CPM responses in females. However, high-intensity running induced only limited analgesic effects and reduced CPM responses, which may be attributed to the activation of endogenous pain modulation.

The effects of physical exercise on structural, functional, and biochemical brain characteristics in individuals with chronic whiplash-associated disorder: A pilot randomized clinical trial

BACKGROUND

Exercise for people with whiplash associated disorder (WAD) induces hypoalgesic effects in some, but hyperalgesic effects in others. We investigated the exercise-induced neurobiological effects of aerobic and strengthening exercise in individuals with chronic WAD.

METHODS

Sixteen participants (8 WAD, 8 pain-free [CON]) were randomised to either aerobic or strengthening exercise. MRI for brain morphometry, functional MRI for brain connectivity, and magnetic resonance spectroscopy for brain biochemistry, were used at baseline and after the 8-week intervention.

RESULTS

There were no differences in brain changes between exercise groups in either the WAD or CON group, therefore aerobic and strengthening data were combined to optimise sample size. After the exercise intervention, the CON group demonstrated increased cortical thickness (left parahippocampus: mean difference = 0.04, 95% CI = 0.07-0.00, p = 0.032; and left lateral orbital frontal cortex: mean difference = 0.03, 95% CI = 0.00-0.06, p = 0.048). The WAD group demonstrated an increase in prefrontal cortex (right medial orbital frontal) volume (mean difference = 95.57, 95% CI = 2.30-192.84, p = 0.046). Functional changes from baseline to follow-up between the default mode network and the insula, cingulate cortex, temporal lobe, and somatosensory and motor cortices, were found in the CON group, but not in the WAD group. There were no changes post-exercise in brain biochemistry.

CONCLUSION

Aerobic and strengthening exercises did not exert differential effects on brain characteristics, however differences in structural and functional changes were found between WAD and CON groups. This suggests that an altered central pain modulatory response may be responsible for differential effects of exercise in individuals with chronic WAD.

Mechanisms hypothesized for pain-relieving effects of exercise in fibromyalgia: a scoping review

Background

Exercise is one of the most recommended management strategies by treatment guidelines for fibromyalgia (FM); however, the mechanism through which exercise improves pain in FM is still unknown.

Objective

We aimed to summarize the hypothesized theoretical mechanisms for the pain-relieving effects of exercise in people with FM.

Eligibility Criteria

Randomized controlled trials (RCTs) in English reporting mechanisms for pain-relieving effects of exercise in the 'Introduction' and 'Discussion' sections and significant within- group or between-group effects of exercise interventions were included.

Sources of Evidence

We searched the databases Ovid MEDLINE(R), EMBASE, CINAHL, COCHRANE, Sports Discuss, and AMED with the keywords: exercise and fibromyalgia until December 2021.

Charting Methods

Two authors independently performed title/abstract, full-text review, and data abstraction using a data abstraction form. The hypothesized mechanisms from individual studies were grouped into three categories.

Results

The literature search resulted in 2147 studies, out of which 220 studies were considered for full-text review. A total of 50 RCTs proposing 29 unique mechanisms for the pain-relieving effects of exercise were included. These mechanisms were divided into three categories: physical, neuro-physiological, and psychological. The neuro-physiological category was further subdivided into exercise-induced hypoalgesia (EIH), pain sensitization, the autonomic system, the immune system, the endocrine system, and miscellaneous categories. The most frequently hypothesized mechanisms were EIH (n = 15), autonomic modulation (n = 7), improved sleep (n = 6), muscle oxygenation (n = 6), self-efficacy (n = 5), mental health (n = 4), and benefits of the aquatic environment (n = 12). While all exercise interventions involved FM patients, most of the supporting evidence for these mechanisms was cited from previous studies conducted on healthy samples. No studies performed analyses to demonstrate causal associations between the mechanisms and outcomes.

Conclusion

Multiple mechanisms were hypothesized for the positive influence of exercise in people with FM. Future studies using causal analyses, such as mediation analysis, are recommended to validate these mechanisms.

Localized Pain and Fatigue During Recovery From Submaximal Resistance Exercise in People With Fibromyalgia

OBJECTIVE

Exercise is recommended as a main treatment in fibromyalgia. However, many people have limited exercise tolerance and report exacerbated pain and fatigue during and following a bout of exercise. This study examined the local and systemic changes in perceived pain and fatigue during exercise and through the 3-day recovery following isometric and concentric exercises in people with and without fibromyalgia.

METHODS

Forty-seven participants with a physician diagnosis of fibromyalgia (44 women; mean age [SD] = 51.3 [12.3] years; mean body mass index [SD] = 30.2 [6.9]) and 47 controls (44 women; mean age [SD] = 52.5 [14.7] years; mean body mass index [SD] = 27.7 [5.6]) completed this prospective, observational cohort study. A bout of submaximal resistance exercise (isometric and concentric) was performed localized to the right elbow flexors on 2 separate days. Baseline attributes (pain, fatigue, physical function, physical activity, and body composition) were assessed prior to exercise. Primary outcomes were: change in perceived pain and fatigue (0 to 10 on the visual analog scale) in the exercising limb and whole body during recovery with movement (immediately, 1 day following exercise, and 3 days following exercise). Secondary outcomes were perceived pain and exertion during exercise performance and pain and fatigue at rest during recovery.

RESULTS

Following a single bout of isometric or concentric exercise, there was increased perceived pain (ηp2 = 0.315) and fatigue (ηp2 = 0.426) in the exercising limb, which was greater in people with fibromyalgia (pain: ηp2 = 0.198; fatigue: ηp2 = 0.211). Clinically, relevant increases in pain and fatigue during exercise and through the 3-day recovery occurred in individuals with fibromyalgia only. Concentric contractions led to greater perceived pain, exertion, and fatigue during exercise compared with isometric exercise for both groups.

CONCLUSIONS

People with fibromyalgia experienced significant pain and fatigue in the exercising muscle during recovery from low-intensity and short-duration resistance exercise, with greater pain during concentric contractions.

IMPACT

These findings highlight a critical need to assess and manage pain and fatigue in the exercising muscles of people with fibromyalgia up to 3 days following a single bout of submaximal resistance exercise.

LAY SUMMARY

If you have fibromyalgia, you might have significant pain and fatigue up to 3 days following an exercise bout, with the pain and fatigue localized to the exercising muscles and no changes in whole-body pain.

Differential Structural Brain Changes Between Responders and Nonresponders After Physical Exercise Therapy for Chronic Nonspecific Neck Pain

OBJECTIVES

Physical exercise therapy is effective for some people with chronic nonspecific neck pain but not for others. Differences in exercise-induced pain-modulatory responses are likely driven by brain changes. We investigated structural brain differences at baseline and changes after an exercise intervention. The primary aim was to investigate changes in structural brain characteristics after physical exercise therapy for people with chronic nonspecific neck pain. The secondary aims were to investigate (1) baseline differences in structural brain characteristics between responders and nonresponders to exercise therapy, and (2) differential brain changes after exercise therapy between responders and nonresponders.

MATERIALS AND METHODS

This was a prospective longitudinal cohort study. Twenty-four participants (18 females, mean age 39.7 y) with chronic nonspecific neck pain were included. Responders were selected as those with ≥20% improvement in Neck Disability Index. Structural magnetic resonance imaging was obtained before and after an 8-week physical exercise intervention delivered by a physiotherapist. Freesurfer cluster-wise analyses were performed and supplemented with an analysis of pain-specific brain regions of interest.

RESULTS

Various changes in grey matter volume and thickness were found after the intervention, for example, frontal cortex volume decreased (cluster-weighted P value = 0.0002, 95% CI: 0.0000-0.0004). We found numerous differences between responders and nonresponders, most notably, after the exercise intervention bilateral insular volume decreased in responders, but increased in nonresponders (cluster-weighted P value ≤ 0.0002).

DISCUSSION

The brain changes found in this study may underpin clinically observed differential effects between responders and nonresponders to exercise therapy for people with chronic neck pain. Identification of these changes is an important step toward personalized treatment approaches.

Fibromyalgia, Pain, and Physical Activity: A Bibliometric Analysis

Fibromyalgia (FM) is a rheumatic disease characterized by pain, fatigue, low-quality sleep, depression, anxiety, stiffness, fall risk, mood disturbance, cognitive impairment, poor physical condition, and other symptoms leading to a worse quality of life. Physical activity (PA) and exercise are effective methods to reduce FM symptoms, including pain. This study presents the first bibliometric study on FM, pain, and PA. An advanced search of the Web of Science (WoS) Core Collection database performed on this topic using was carried out traditional bibliometric laws. A total of 737 documents were found. Annual publications presented an exponentially growing trend (R2 = 85.3%). Rheumatology International, Kaisa Mannerkorpi, and the USA were the journal, co-author, and country most productive, respectively. The exponential growth of annual publications on FM, PA, and pain shows the high interest of researchers and publishers in this topic. The document "Fibromyalgia A Clinical Review" was the most cited. Moreover, Kaisa Mannerkorpi was the most prolific co-author, Rheumatology International was the most prolific journal, "Fibromyalgia: a clinical review" was the most highly cited document, and Daniel Clauw was the most cited co-author.

Is low intensity exercise sufficient to induce exercise-induced pain threshold modulation in people with persistent pain?

OBJECTIVES

We investigated whether a 12-min walk test (12MWT) yielded exercise-induced pain threshold modulation (EIPM) within people with persistent pain and whether baseline self-report and pain sensitivity measures differed according to these responses.

DESIGN

Cross-sectional study.

METHODS

Two cohorts (tertiary/community) (n = 88) with persistent pain underwent pressure pain threshold (PPT) testing before and after a 12MWT to determine exercise-induced pain threshold modulation responses. Baseline self-report (pain severity, pain distribution, psychological distress, sleep) and baseline widespread pain sensitivity (WPS) (high/low) were recorded. Within and between-group differences were analysed using paired t-tests and repeated measure analyses of covariance. Individual EIPM responses were categorised as hyperalgesic, no change and hypoalgesic responses. Differences in baseline self-report and pain sensitivity measures between EIPM categories were investigated.

RESULTS

No significant within- or between-group differences in PPT following the 12MWT were detected (p > 0.05). Individual responses showed that up to 30% of the community and 44% of the tertiary cohort demonstrated >20% change in PPT (in either direction). Significant differences were shown in pain distribution (p = 0.002) and baseline WPS (p = 0.001) between people with hyperalgesic, no change, hypoalgesic responses. People with 4-5 pain regions were more likely hyperalgesic (χ2 = 9.0, p = 0.003); people with low baseline WPS were more likely to demonstrate no change (p = 0.002).

CONCLUSION

Low or self-selected intensity exercise was insufficient to induce exercise-induced pain modulation at group level. Individual responses were variable with pain distribution and baseline WPS differing between responses. Future research could evaluate responses and associated factors in larger samples with high baseline pain sensitivity specifically.

Assessing Walking Programs in Fibromyalgia: A Concordance Study between Measures

This study analyzes the degree of agreement between three self-report measures (Walking Behavior, WALK questionnaire and logbooks) assessing adherence to walking programs through reporting their components (minutes, rests, times a week, consecutive weeks) and their concordance with a standard self-report of physical activity (IPAQ-S questionnaire) and an objective, namely number of steps (pedometer), in 275 women with fibromyalgia. Regularized partial correlation networks were selected as the analytic framework. Three network models based on two different times of assessment, namely T1 and T2, including 6 weeks between both, were used. WALK and the logbook were connected with Walking Behavior and also with the IPAQ-S. The logbook was associated with the pedometers (Z-score > 1 in absolute value). When the behavior was assessed specifically and in a detailed manner, participants’ results for the different self-report measures were in agreement. Specific self-report methods provide detailed information that is consistent with validated self-report measures (IPAQ-S) and objective measures (pedometers). The self-report measures that assess the behavioral components of physical activity are useful when studying the implementation of walking as physical exercise.

Does aerobic exercise effect pain sensitisation in individuals with musculoskeletal pain? A systematic review

BACKGROUND

Pain sensitisation plays a major role in musculoskeletal pain. However, effective treatments are limited, and although there is growing evidence that exercise may improve pain sensitisation, the amount and type of exercise remains unclear. This systematic review examines the evidence for an effect of aerobic exercise on pain sensitisation in musculoskeletal conditions.

METHODS

Systematic searches of six electronic databases were conducted. Studies were included if they examined the relationship between aerobic physical activity and pain sensitisation in individuals with chronic musculoskeletal pain, but excluding specific patient subgroups such as fibromyalgia. Risk of bias was assessed using Cochrane methods and a qualitative analysis was conducted.

RESULTS

Eleven studies (seven repeated measures studies and four clinical trials) of 590 participants were included. Eight studies had low to moderate risk of bias. All 11 studies found that aerobic exercise increased pressure pain thresholds or decreased pain ratings in those with musculoskeletal pain [median (minimum, maximum) improvement in pain sensitisation: 10.6% (2.2%, 24.1%)]. In these studies, the aerobic exercise involved walking or cycling, performed at a submaximal intensity but with incremental increases, for a 4-60 min duration. Improvement in pain sensitisation occurred after one session in the observational studies and after 2-12 weeks in the clinical trials.

CONCLUSIONS

These findings provide evidence that aerobic exercise reduces pain sensitisation in individuals with musculoskeletal pain. Further work is needed to determine whether this translates to improved patient outcomes, including reduced disability and greater quality of life.

Fibromyalgia syndrome: epidemiology, diagnosis and treatment

Fibromyalgia syndrome (FMS) profoundly impacts patients' quality of life with its symptoms and clinical signs. Fibromyalgia syndrome impairs daily living activities, reduces work efficiency and raises health-related costs. Although the prevalence rates vary depending on geographical location and diagnostic criteria, it is a common disorder worldwide. Females have a higher prevalence of fibromyalgia syndrome, with varied rates, and there is an increase in prevalence rates with age. Although its etiopathogenesis has not been fully elucidated, various hypotheses have been proposed that central sensitization is at the core of the process. Fibromyalgia syndrome diagnostic approaches have advanced significantly over time, moving away from pain assessments alone and emphasizing multiple clinical signs of FMS. This condition has raised physicians' and researchers' awareness of non-pain symptoms. Considering the complicated etiopathogenesis of fibromyalgia syndrome, diverse pathways connected with symptoms, and multiple clinical presentations, it becomes clear that drug and non-drug treatments should be chosen in combination.

Is Irritable Bowel Syndrome Considered as Comorbidity in Clinical Trials of Physical Therapy Interventions in Fibromyalgia? A Scoping Review

Evidence supports the presence of comorbid conditions, e.g., irritable bowel syndrome (IBS), in individuals with fibromyalgia (FM). Physical therapy plays an essential role in the treatment of FM; however, it is not currently known whether the IBS comorbidity is considered in the selection criteria for clinical trials evaluating physiotherapy in FM. Thus, the aim of the review was to identify whether the presence of IBS was considered in the selection criteria for study subjects for those clinical trials that have been highly cited or published in the high-impact journals investigating the effects of physical therapy in FM. A literature search in the Web of Science database for clinical trials that were highly cited or published in high-impact journals, i.e., first second quartile (Q1) of any category of the Journal Citation Report (JCR), investigating the effects of physical therapy in FM was conducted. The methodological quality of the selected trials was assessed with the Physiotherapy Evidence Database (PEDro) scale. Authors, affiliations, number of citations, objectives, sex/gender, age, and eligibility criteria of each article were extracted and analyzed independently by two authors. From a total of the 412 identified articles, 20 and 61 clinical trials were included according to the citation criterion or JCR criterion, respectively. The PEDro score ranged from 2 to 8 (mean: 5.9, SD: 0.1). The comorbidity between FM and IBS was not considered within the eligibility criteria of the participants in any of the clinical trials. The improvement of the eligibility criteria is required in clinical trials on physical therapy that include FM patients to avoid selection bias.

The Effects of Transcranial Direct Current Stimulation Combined with Aerobic Exercise on Pain Thresholds and Electroencephalography in Healthy Adults

OBJECTIVES

We examined whether transcranial direct current stimulation (tDCS) combined with aerobic exercise (AE) modulated the pressure pain threshold (PPT) and peak alpha frequency (PAF) measured via resting electroencephalography.

DESIGN

Single-blind experimental study with a cross-over design.

SETTING

Neuro Rehabilitation Research Center, Kio University.

SUBJECTS

Ten healthy controls participated in this study.

METHODS

Three types of sessions--(i) tDCS, (ii) Sham tDCS/AE, and (iii) tDCS/AE--were tested in this investigation. Anodal stimulation (2 mA, 20 minutes) was applied over the left primary motor cortex. Each session was 20 minutes long. We used the PPT and short-form Profile of Mood States-Brief, as well as PAF measured via resting-electroencephalography, to investigate the effects of tDCS and AE. Heart rate and scores on the Borg scale were used to confirm exercise intensity. PAF was calculated in four regions of interest: frontal, central, parietal, and occipital areas.

RESULTS

The change ratio of PPT increased during each session. The maximum change ratio of PPT were tDCS: 40.7%, Sham tDCS/AE: 51.5%, and tDCS/AE: 83.4%. change ratio of PPT was earlier and higher in the tDCS/AE trials compared with the other sessions. Negative mood was improved after session completion. Significant differences in PAF were found in the occipital area in the Sham tDCS/AE and tDCS/AE sessions.

CONCLUSIONS

The combined tDCS and AE intervention induced significant changes in PPT in a single session, with a PAF that was earlier and higher than those produced during the Sham tDCS/AE and tDCS sessions.

The effect of long-term poor sleep quality on risk of back-related disability and the modifying role of physical activity

Sleep problems and regular leisure time physical activity (LTPA) are interrelated and have contrasting effects on risk of back pain. However, no studies have investigated the influence of long-term poor sleep quality on risk of back-related disability, or if LTPA modifies this association. The study comprised data on 8601 people who participated in three consecutive surveys over ~ 22 years, and who reported no chronic back pain at the two first surveys. Adjusted risk ratios (RRs) for back-related disability were calculated at the last survey, associated with the joint effect of changes in sleep quality between the two first surveys and meeting physical activity guidelines at the second survey. Compared to people with long-term good sleep, people with long-term poor sleep had nearly twice the risk of back-related disability (RR 1.92, 95% CI 1.48-2.49). There was no statistical interaction between sleep and LTPA but people who reported long-term poor sleep and meeting the physical activity guidelines had 35% lower risk of back-related disability compared to people with same level of sleep problems, but who not met the guidelines. These findings suggest that long-term poor sleep quality contributes to a substantially increased risk of chronic and disabling back pain irrespective of LTPA.

Endogenous Modulation of Pain: The Role of Exercise, Stress, and Cognitions in Humans

BACKGROUND

Pain is a complex and highly subjective phenomenon that can be modulated by several factors. On the basis of results from experimental and clinical studies, the existence of endogenous pain modulatory mechanisms that can increase or diminish the experience of pain is now accepted.

METHODS

In this narrative review, the pain modulatory effects of exercise, stress, and cognitions in humans are assessed.

RESULTS

Experimental studies on the effect of exercise have revealed that pain-free participants show a hypoalgesic response after exercise. However, in some patients with chronic pain, this response is reduced or even hyperalgesic in nature. These findings will be discussed from a mechanistic point of view. Stress is another modulator of the pain experience. Although acute stress may induce hypoalgesia, ongoing clinical stress has detrimental effects on pain in many patients with chronic pain conditions, which have implications for the understanding, assessment, and treatment of stress in patients with pain. Finally, cognitive strategies play differing roles in pain inhibition. Two intuitive strategies, thought suppression and focused distraction, will be reviewed as regards experimental, acute, and chronic pain.

CONCLUSION

On the basis of current knowledge on the role of exercise, stress, and cognitive pain control strategies on the modulation of pain, implications for treatment will be discussed.

Women with Fibromyalgia Prefer Resistance Exercise with Heavy Loads-A Randomized Crossover Pilot Study

Fibromyalgia (FM) is a chronic pain condition associated with impaired muscle strength and exercise-induced pain. Physical exercise has been highlighted, by international clinical guidelines and stakeholders, as an essential component of rehabilitation in FM. Exposure to pain during exercise is generally correlated with elevated lactate levels and, additionally, is one known reason for persons with FM to avoid physical exercise and activity. A crossover design was used to test and evaluate an approach consisting of resistance exercise with heavy loads and a low number of repetitions among ten women with FM. The participants were consecutively recruited to test and perform exercise with two different resistance levels (A = light/moderate load, and B = heavy load) in a randomized crossover trial using an AB/BA setting. Results showed that the heavy load exercise session was experienced as more positive than the light/moderate load exercise session and that lower lactate levels followed exercise with heavier weight loads. This is promising and indicates that the approach of heavy weight loads and accustomed repetitions is accepted in FM and has the potential to attenuate hesitation to exercise due to exercise-induced pain. However, these effects need to be further investigated in more extensive studies.

A training program for fibromyalgia management: A 5-year pilot study

We studied the effects of a specific cardio training program lasting 5 years on pain and quality of life in fibromyalgia patients.

Exercise-induced hypoalgesia after acute and regular exercise: experimental and clinical manifestations and possible mechanisms in individuals with and without pain

This review describes methodology used in the assessment of the manifestations of exercise-induced hypoalgesia in humans and previous findings in individuals with and without pain. Possible mechanisms and future directions are discussed.

Exercise and physical activity is recommended treatment for a wide range of chronic pain conditions. In addition to several well-documented effects on physical and mental health, 8 to 12 weeks of exercise therapy can induce clinically relevant reductions in pain. However, exercise can also induce hypoalgesia after as little as 1 session, which is commonly referred to as exercise-induced hypoalgesia (EIH). In this review, we give a brief introduction to the methodology used in the assessment of EIH in humans followed by an overview of the findings from previous experimental studies investigating the pain response after acute and regular exercise in pain-free individuals and in individuals with different chronic pain conditions. Finally, we discuss potential mechanisms underlying the change in pain after exercise in pain-free individuals and in individuals with different chronic pain conditions, and how this may have implications for clinical exercise prescription as well as for future studies on EIH.

Sex Difference in Trigeminal Neuropathic Pain Response to Exercise: Role of Oxidative Stress

Aim

Orofacial chronic neuropathic pain commonly occurs following trigeminal nerve injuries. We investigated whether swimming exercise can reduce trigeminal neuropathic pain through improving antioxidant capacity.

Materials and Methods

Twenty-eight Wistar rats of either sex and 180–220 grams were divided into 4 groups as sham, neuropathy, neuropathy + single bout exercise, and neuropathy + 2 weeks of exercise. Trigeminal neuropathy was carried out through chronic constriction injury (CCI) of infraorbital nerve. Protocols of exercise were included a single bout session (45 minutes) and a 2-week (45 minutes/day/6 days a week) swimming exercise. Mechanical allodynia was detected using Von Frey filaments. The activity of the serum antioxidant enzymes glutathione peroxidase and superoxides dismutase was assayed using ELISA kits.

Results

We found that CCI significantly reduced facial pain threshold in both sexes (P < 0.05). Both swimming exercise protocols significantly reduced mechanical allodynia in female rats compared to the sham group; however, only 2 weeks of exercise were significantly effective in male rats. The activity of antioxidant enzyme glutathione peroxidase significantly (P < 0.05) decreased following CCI in female rats against that in the sham group and 2-week exercise significantly (P < 0.05) increased it toward the control level. The levels of glutathione peroxidase in male rats and superoxidase dismutase in both sexes were not significantly different compared to their sham groups.

Conclusion

Swimming exercise alleviates trigeminal neuropathic pain in both sexes. Oxidative stress as a possible mechanism was involved in the effect of exercise on female rat trigeminal neuropathy.

Effectiveness of High-Intensity Interval Training vs Moderate-Intensity Continuous Training in Patients With Fibromyalgia: A Pilot Randomized Controlled Trial

OBJECTIVE

To compare the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) combined with strengthening and stretching exercises in patients with fibromyalgia.

DESIGN

Interventional, single-blind, randomized controlled trial.

SETTING

Outpatient rehabilitation center.

PARTICIPANTS

Women with fibromyalgia (N=60) were randomized to HIIT, MICT, and control groups.

INTERVENTIONS

HIIT included a 5-minute warm-up at 50% of peak heart rate and 4 cycles of 4 minutes at 80%-95% of peak heart rate followed by 3-minute recovery intervals at 70% of peak heart rate. MICT consisted of 45 minutes at 65%-70% of peak heart rate. Each aerobic training session was followed by standardized strengthening and stretching exercises. The programs performed using cycle ergometers for 5 sessions per week for 6 weeks. The control group did not participate in any supervised exercise sessions.

MAIN OUTCOME MEASURES

The primary outcome measure was the Fibromyalgia Impact Questionnaire (FIQ). The secondary outcome measures were visual analog scale for pain, Short Form-36 Health Survey (SF-36), cardiopulmonary exercise test (CPET), and body composition parameters.

RESULTS

Fifty-five participants completed the study. There was no significant difference in FIQ between HIIT vs MICT (1.03; 95% CI, -9.67 to 11.75) after treatment. Group-time interactions were significant for the FIQ between interventions and control (HIIT vs control, -16.20; 95% CI, -27.23 to -5.13 and MICT vs control, -17.24; 95% CI, -28.27 to -6.22) (all P<.001). There were significant group-time interactions for the pain, SF-36, and CPET parameters between treatments and control (all P<.05). Body weight, fat percentage, fat mass, and body mass index improved significantly (all P<.05) only in the MICT group after treatment.

CONCLUSIONS

The HIIT plus strengthening and stretching exercises and MICT plus strengthening and stretching exercises interventions showed significant improvements for the effect of fibromyalgia, pain degree, functional capacity, and quality of life compared with the control group. HIIT was not superior to MICT. Furthermore, body composition parameters were improved significantly only for the MICT group.

Preferred exercise and mental health of the patients with fibromyalgia syndrome

BACKGROUND AND PURPOSE

Preferred exercise may be beneficial for the mental health of patients with fibromyalgia syndrome (FMS).This study aimed to investigate the effects of preferred exercise on the quality of life (Qol), depression, and mood states of the patients with FMS.

MATERIALS AND METHODS

This study was a nonrandomized controlled trial. The patients with FMS were divided into an experimental group (EG; n = 22) and a control group (CG; n = 14). The patients in the EG performed their preferred exercise (resistance, walking, or stretching) for 12 weeks. CG went to a waiting list. Fibromyalgia Impact Questionnaire, Beck Depression Inventory, and Brunel Mood Scale were used to evaluate the outcomes.

RESULTS

The EG exhibited a decrease in the total impact of FMS on the Qol, depression, tension, and mental confusion (p < 0.01).

CONCLUSION

Preferred exercises reduced the impact of FMS on the Qol, depression, and mental confusion of patients with FMS.

LOWER EXTREMITY AEROBIC EXERCISE AS A TREATMENT FOR SHOULDER PAIN

BACKGROUND

Shoulder girdle pain is a common disabling complaint with a high lifetime prevalence. Interventions aimed at decreasing shoulder pain without stressing shoulder girdle structures have the potential to improve participation in multimodal shoulder rehabilitation programs.

HYPOTHESIS/PURPOSE

The aim of this study was to determine the acute effects of moderate intensity lower extremity exercise on mechanically induced shoulder pain in individuals without shoulder injury. It was hypothesized that participants would exhibit less shoulder pain, as indicated by increased pain thresholds, following lower extremity exercise.

STUDY DESIGN

Repeated measures study.

METHODS

Thirty (30) healthy participants were recruited to participate in this study. Pain pressure algometry was used to mechanically induce shoulder pain over the infraspinatus muscle belly. This was performed on the dominant shoulder before and immediately after performing 10 minutes of moderate intensity lower extremity exercise using a recumbent exercise machine. Heart rate and rate of perceived exertion were measured following exercise. Repeated measures ANOVA was used to compare pain pressure threshold scores between the baseline and post-exercise time points. Significance was set at p ≤ 0.05 a priori. Effect size (ES) was calculated using Glass's Δ.

RESULTS

Moderate intensity lower extremity aerobic exercise led to significantly (F = 8.471, p = 0.003) decreased evoked shoulder pain in healthy adults with moderate effect sizes (0.30-0.43).

CONCLUSIONS

Lower extremity aerobic exercise significantly decreased pain of the infraspinatus in this sample of young healthy participants. Utilization of lower extremity exercise may be of benefit for younger patients to decreased acute shoulder pain.

LEVEL OF EVIDENCE

2b: individual cohort study.

Chronic Pain Self-Management Support With Pain Science Education and Exercise (COMMENCE) for People With Chronic Pain and Multiple Comorbidities: A Randomized Controlled Trial

OBJECTIVE

To investigate the effectiveness of chronic pain self-management support with pain science education and exercise (COMMENCE) on improving function, pain interference, work status, pain intensity, fatigue, psychological factors associated with pain, health care visits, satisfaction, and perceived change compared with usual care.

DESIGN

Parallel group randomized controlled trial with 1- and 12-week follow-ups.

SETTING

Community health center.

PARTICIPANTS

Adults (N=102) with chronic noncancer pain referred for self-management support. Eighty of 102 participants completed 12-week follow-up assessments. No participants withdrew with adverse events.

INTERVENTIONS

Participants were randomized to COMMENCE or usual care.

MAIN OUTCOME MEASURES

Primary: Function measured using the Short Musculoskeletal Function Assessment-Dysfunction Index. Secondary: Short Musculoskeletal Function Assessment-Bother Index, Patient Reported Outcomes Measurement Information System pain interference, work status, numeric pain, and fatigue rating scales, Tampa Scale of Kinesiophobia, Pain Catastrophizing Scale, Pain Self-Efficacy Scale, Neurophysiology of Pain Questionnaire, number of health care visits, satisfaction, and global rating of change.

RESULTS

COMMENCE resulted in greater improvements in function (mean difference [MD] at 12-wk follow-up=-8.0; 95% CI, -14.7 to -1.3), bother with functional difficulties (MD, -12.0; 95% CI, -20.8 to -3.2), pain intensity (MD, -1.0; 95% CI, -2.1 to -0.1), catastrophizing (MD , -8.2; 95% CI, -14.5 to -2.0), self-efficacy (MD, 7.0; 95% CI, 0.8-13.2), knowledge (MD, 2.8; 95% CI, 1.6-3.9), satisfaction (MD, 1.2; 95% CI, 0.7-1.8), and perceived change (MD, 1.4; 95% CI, 0.8-2.1). There were no significant between-group differences in pain interference, work, fatigue, depressive symptoms, or health care visits.

CONCLUSION

COMMENCE is more effective than usual care at improving function, pain, catastrophic thinking, self-efficacy, pain knowledge, satisfaction, and perceived change but not pain interference, work status, fatigue, depressive symptoms, or health care visits.

The joint effect of insomnia symptoms and lifestyle factors on risk of self-reported fibromyalgia in women: longitudinal data from the HUNT Study

OBJECTIVES

To investigate the association between insomnia symptoms and risk of self-reported fibromyalgia in women, and to explore whether leisure time physical activity and body mass index (BMI) modify this association.

DESIGN

Prospective cohort study.

SETTING

We used longitudinal data from the Norwegian Nord-Trøndelag Health Study collected in 1995-1997 (baseline) and 2006-2008 (follow-up).

PARTICIPANTS

A total of 14 172 women who reported to be free from fibromyalgia at baseline.

PRIMARY OUTCOME MEASURES

We estimated adjusted risk ratios (RRs) with 95% CI for self-reported fibromyalgia at follow-up associated with baseline insomnia symptoms, leisure time physical activity and BMI.

RESULTS

Overall, 466 incident cases of fibromyalgia were reported during the follow-up period of approximately 11 years, corresponding to a crude absolute risk (AR) of 3.3%. Compared with women without insomnia symptoms (crude AR=2.8%), women who reported one, two or three symptoms had RRs of fibromyalgia of 1.39 (95% CI: 1.08 to 1.80), 1.86 (95% CI: 1.33 to 2.59) and 2.66 (95% CI: 1.75 to 4.06), respectively. Compared with highly physically active women without insomnia symptoms (crude AR=2.7%), women with one or more insomnia symptoms had a RR of fibromyalgia of 1.90 (95% CI: 1.30 to 2.79) if they reported low physical activity and a RR of 1.55 (95% CI: 1.12 to 2.13) if they reported high physical activity. We found no synergistic effect between insomnia symptoms and BMI on risk of fibromyalgia; however, overweight and obese women with one or more insomnia symptoms had RRs of 2.35 (95% CI: 1.73 to 3.21) and 2.18 (95% CI: 1.42 to 3.35) compared with the reference group of normal weight women without insomnia symptoms (crude AR=2.3%).

CONCLUSIONS

Insomnia symptoms are strongly and positively associated with risk of fibromyalgia in adult women. Leisure time physical activity may compensate for some of the adverse effect of insomnia symptoms on risk of fibromyalgia.

Walking increases pain tolerance in humans: an experimental cross-over study

Background and aims

Exercise is commonly used as treatment for chronic pain with positive long-term effects on pain and pain-related disability. In pain-free subjects, hypoalgesia following an acute bout of exercise compared with a control condition has consistently been demonstrated also known as exercise-induced hypoalgesia (EIH). Walking exercise, a low intensity aerobic exercise, is frequently used in clinical practice as an easily applicable intervention for patients with chronic pain. Walking exercise is furthermore recommended as an effective treatment for patients with chronic musculoskeletal pain conditions to alleviate pain and reduce disability, however, the effect of walking on pain sensitivity is currently unknown. The aims of the present study were to investigate (1) the acute effect of walking on pain sensitivity, and (2) the relative (between-subjects) and absolute (within-subject) test-retest reliability of the hypoalgesic response across two sessions separated by 1 week.

Methods

In this randomised experimental cross-over study including two identical sessions, 35 pain-free subjects performed a standardized 6 min walking test and a duration-matched quiet rest condition in a randomized and counterbalanced order in each session. Before and after both conditions, handheld pressure pain thresholds (PPTs) were assessed at the thigh and shoulder, and pressure pain thresholds (cPPT) and pain tolerance (cPTT) were assessed with computer-controlled cuff algometry at the lower leg. Change in the pain sensitivity measures were analysed with repeated-measures ANOVAs, and test-retest reliability with intraclass correlation coefficients (ICC) and agreements in classification of EIH responders/non-responders between the two sessions.

Results

All subjects completed the walking conditions in both session 1 and session 2. The perceived intensity of walking assessed with rating of perceived exertion (RPE) and walking distance did not differ significantly between session 1 (distance: 632.5 ± 75.2 meters, RPE: 10.9 ± 1.9) and session 2 (distance: 642.1 ± 80.2 meters, RPE: 11.0 ± 2.4) (p > 0.11). Moreover, RPE showed excellent relative reliability with an ICC value of 0.95 [95%CI: 0.90–0.97]. Walking increased pain tolerance (mean difference: 2.6 kPa [95%CI: 0.5–4.9 kPa; p = 0.02]), but not pain thresholds compared with rest in both sessions. Hypoalgesia after walking demonstrated fair to good relative reliability (ICC = 0.61), however the agreement in classification of EIH responders/non-responders (absolute reliability) across sessions was low and not significant (κ = 0.19, p = 0.30).

Conclusions

Walking consistently increased pain tolerance but not pain thresholds compared with a duration-matched control condition with fair to good relative reliability between sessions. Based on classification of EIH responders/non-responders the absolute reliability between the two sessions was low indicating individual variance in the EIH response. Future studies should investigate the hypoalgesic effect of a walking exercise in a clinical pain population.

Exercise-induced hypoalgesia is present in people with Parkinson's disease: Two observational cross-sectional studies

BACKGROUND

Exercise is prescribed for people with Parkinson's disease to address motor and non-motor impairments, including pain. Exercise-induced hypoalgesia (i.e., an immediate reduction in pain sensitivity following exercise) is reported in the general population; however, the immediate response of pain sensitivity to exercise in people with Parkinson's disease is unknown. The purpose of this study was to investigate if exercise-induced hypoalgesia is present following isometric and aerobic exercise in people with Parkinson's disease, and if so, if it varies with the dose of aerobic exercise.

METHODS

Thirty people with idiopathic Parkinson's disease and pain-free age-matched controls completed two observational studies evaluating the response to: (a) right arm isometric exercise; and (b) treadmill walking at low and moderate intensities. Pressure pain thresholds were measured over biceps brachii and quadriceps muscles immediately before and after exercise, with increased thresholds after exercise indicating exercise-induced hypoalgesia.

RESULTS

Pressure pain thresholds increased in the Parkinson's disease group at all tested sites following all exercise bouts (e.g., isometric exercise, right bicep 29%; aerobic exercise, quadriceps, moderate intensity 8.9%, low intensity 7.1% (p ≤ 0.008)), with no effect of aerobic exercise dose (p = 0.159). Similar results were found in the control group.

CONCLUSIONS

Overall, people with Parkinson's disease experienced an exercise-induced hypoalgesia response similar to that of the control group, the extent of which did not vary between mild and moderate doses of aerobic exercise. Further research is warranted to investigate potential longer term benefits from exercise in the management of pain in this population.

SIGNIFICANCE

Isometric and aerobic exercise reduces pain sensitivity in people with Parkinson's disease. As exercise is important for people with Parkinson's disease, these results provide assurance that people with Parkinson's disease and pain can exercise without an immediate increase in pain sensitivity. The reduction in pain sensitivity with both modes and with low and moderate intensities of aerobic exercise suggests that people with Parkinson's disease can safely choose the mode and intensity of exercise that best suits their needs.

Land- and pool-based intervention in female fibromyalgia patients: A randomized-controlled trial

OBJECTIVES

The aim of this study was to assess the effect of a standard physical rehabilitation intervention (SPRI) program, in pool-based (SPRI-P) and land-based (SPRI-L) environments, applied to female fibromyalgia (FM) patients with mild-to-moderate symptoms during a period of 20 weeks.

PATIENTS AND METHODS

Between September 2016 and September 2017, a total of 73 female FM patients (mean age 48.2±6.8 years; range, 30 to 59 years) who suffered from FM were included in this study on a voluntary basis. The SPRI program was applied to the patients for 20 weeks. The severity of FM was assessed using the Fibromyalgia Impact Questionnaire. The dependent variables including self- perceived pain, perceived fatigue, aerobic capacity, depressive symptoms, and the overall impact of FM were evaluated.

RESULTS

Self-perceived pain, perceived fatigue, overall impact of FM (p<0.05) and depressive symptoms (p<0.001) of the participants in the SPRI-P program decreased in the post-test values, compared to the pre-test values. Using the SPRI-L program, a significant improvement in the aerobic capacity (maximum consumption of relative oxygen and distance in meters), overall impact of FM (p<0.05), and depressive symptoms (p<0.01) was observed.

CONCLUSION

Our study results indicated that the SPRI-P program yielded improvements in patients with FM in self-perceived pain, perceived fatigue, depressive symptoms, and overall impact, as well as improving the aerobic capacity. In addition, in the SPRI-L program, the participants increased their capacities, self-perceived pain, and overall impact of FM.

Prescribed Versus Preferred Intensity Resistance Exercise in Fibromyalgia Pain

Exercise is the treatment of choice for fibromyalgia (FM), but little is known about resistance exercise prescription to modulate pain in this condition. This study aimed to compare the effects of different resistance exercise models, comprising self-selected or prescribed intensity, on pain in FM patients. In a cross-over fashion, 32 patients underwent the following sessions: (i) standard prescription (STD; 3 × 10 repetitions at 60% of maximal strength); (ii) self-selected load with fixed number of repetitions (SS); (iii) self-selected load with volume load (i.e., load × sets × repetitions) matched for STD (SS-VM); and (iv) self-selected load with a free number of repetitions until achieving score 7 of rating perceived exertion (SS-RPE). Pain, assessed by Visual Analogic Scale (VAS) and Short-Form McGill Pain Questionnaire (SF-MPQ), was evaluated before and 0, 24, 48, 72, and 96 h after the sessions. Load was significantly lower in SS, SS-VM, SS-RPE than in STD, whereas rating perceived exertion and volume load were comparable between sessions. VAS scores increased immediately after all sessions (p < 0.0001), and reduced after 48, 72, 96 h (p < 0.0001), remaining elevated compared to pre-values. SF-MPQ scores increased immediately after all exercise sessions (p = 0.025), then gradually reduced across time, reaching baseline levels at 24 h. No significant differences between sessions were observed. Both prescribed and preferred intensity resistance exercises failed in reducing pain in FM patients. The recommendation that FM patients should exercise at preferred intensities to avoid exacerbated pain, which appears to be valid for aerobic exercise, does not apply to resistance exercise.

Office-Cycling: A Promising Way to Raise Pain Thresholds and Increase Metabolism with Minimal Compromising of Work Performance

Aim

Establishing the effects of low intensity cycling (LC), moderate intensity cycling (MC), and standing at a simulated office workstation on pain modulation, work performance, and metabolic expenditure.

Methods

36 healthy adults (21 females), mean age 26.8 (SD 7.6) years, partook in this randomized 3 × 3 crossover trial with 75 minutes of LC on 20% of maximum aerobic power (MAP) output, 30 minutes of MC on 50% of MAP, and standing 30 minutes with 48-hour wash-out periods. Outcome measures were pain modulation (pressure pain threshold (PPT) and thermal pain threshold)), work performance (transcription, mouse pointing, and cognitive performance), and metabolic expenditure.

Results

PPTs increased in all conditions. PPT trapezius showed the highest increase after LC, 39.3 kilopascals (kPa) (15.6; 78.6), compared to MC, 17.0 kPa (2.8; 49.9), and standing, 16.8 kPa (-5.6; 39.4), p = 0.015. Transcription was reduced during LC and MC. Mouse pointing precision was best during standing and worst and slowest during MC. Cognitive performance did not differ between conditions. Metabolic expenditure rates were 1.4 (1.3; 1.7), 3.3 (2.3; 3.7), and 7.5 (5.8; 8.7) kcal/minute during standing, LC, and MC, respectively (p < 0.001).

Conclusions

LC seems to be the preferred option; it raised PPTs, more than doubled metabolic expenditure, whilst minimally influencing work performance.

Whole body vibration exercise training for fibromyalgia

BACKGROUND

Exercise training is commonly recommended for adults with fibromyalgia. We defined whole body vibration (WBV) exercise as use of a vertical or rotary oscillating platform as an exercise stimulus while the individual engages in sustained static positioning or dynamic movements. The individual stands on the platform, and oscillations result in vibrations transmitted to the subject through the legs. This review is one of a series of reviews that replaces the first review published in 2002.

OBJECTIVES

To evaluate benefits and harms of WBV exercise training in adults with fibromyalgia.

SEARCH METHODS

We searched the Cochrane Library, MEDLINE, Embase, CINAHL, PEDro, Thesis and Dissertation Abstracts, AMED, WHO ICTRP, and ClinicalTrials.gov up to December 2016, unrestricted by language, to identify potentially relevant trials.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in adults with the diagnosis of fibromyalgia based on published criteria including a WBV intervention versus control or another intervention. Major outcomes were health-related quality of life (HRQL), pain intensity, stiffness, fatigue, physical function, withdrawals, and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, extracted data, performed risk of bias assessments, and assessed the quality of evidence for major outcomes using the GRADE approach. We used a 15% threshold for calculation of clinically relevant differences.

MAIN RESULTS

We included four studies involving 150 middle-aged female participants from one country. Two studies had two treatment arms (71 participants) that compared WBV plus mixed exercise plus relaxation versus mixed exercise plus relaxation and placebo WBV versus control, and WBV plus mixed exercise versus mixed exercise and control; two studies had three treatment arms (79 participants) that compared WBV plus mixed exercise versus control and mixed relaxation placebo WBV. We judged the overall risk of bias as low for selection (random sequence generation), detection (objectively measured outcomes), attrition, and other biases; as unclear for selection bias (allocation concealment); and as high for performance, detection (self-report outcomes), and selective reporting biases.The WBV versus control comparison reported on three major outcomes assessed at 12 weeks post intervention based on the Fibromyalgia Impact Questionnaire (FIQ) (0 to 100 scale, lower score is better). Results for HRQL in the control group at end of treatment (59.13) showed a mean difference (MD) of -3.73 (95% confidence interval [CI] -10.81 to 3.35) for absolute HRQL, or improvement of 4% (11% better to 3% worse) and relative improvement of 6.7% (19.6% better to 6.1% worse). Results for withdrawals indicate that 14 per 100 and 10 per 100 in the intervention and control groups, respectively, withdrew from the intervention (RR 1.43, 95% CI 0.27 to 7.67; absolute change 4%, 95% CI 16% fewer to 24% more; relative change 43% more, 95% CI 73% fewer to 667% more). The only adverse event reported was acute pain in the legs, for which one participant dropped out of the program. We judged the quality of evidence for all outcomes as very low. This study did not measure pain intensity, fatigue, stiffness, or physical function. No outcomes in this comparison met the 15% threshold for clinical relevance.The WBV plus mixed exercise (aerobic, strength, flexibility, and relaxation) versus control study (N = 21) evaluated symptoms at six weeks post intervention using the FIQ. Results for HRQL at end of treatment (59.64) showed an MD of -16.02 (95% CI -31.57 to -0.47) for absolute HRQL, with improvement of 16% (0.5% to 32%) and relative change in HRQL of 24% (0.7% to 47%). Data showed a pain intensity MD of -28.22 (95% CI -43.26 to -13.18) for an absolute difference of 28% (13% to 43%) and a relative change of 39% improvement (18% to 60%); as well as a fatigue MD of -33 (95% CI -49 to -16) for an absolute difference of 33% (16% to 49%) and relative difference of 47% (95% CI 23% to 60%); and a stiffness MD of -26.27 (95% CI -42.96 to -9.58) for an absolute difference of 26% (10% to 43%) and a relative difference of 36.5% (23% to 60%). All-cause withdrawals occurred in 8 per 100 and 33 per 100 withdrawals in the intervention and control groups, respectively (two studies, N = 46; RR 0.25, 95% CI 0.06 to 1.12) for an absolute risk difference of 24% (3% to 51%). One participant exhibited a mild anxiety attack at the first session of WBV. No studies in this comparison reported on physical function. Several outcomes (based on the findings of one study) in this comparison met the 15% threshold for clinical relevance: HRQL, pain intensity, fatigue, and stiffness, which improved by 16%, 39%, 46%, and 36%, respectively. We found evidence of very low quality for all outcomes.The WBV plus mixed exercise versus other exercise provided very low quality evidence for all outcomes. Investigators evaluated outcomes on a 0 to 100 scale (lower score is better) for pain intensity (one study, N = 23; MD -16.36, 95% CI -29.49 to -3.23), HRQL (two studies, N = 49; MD -6.67, 95% CI -14.65 to 1.31), fatigue (one study, N = 23; MD -14.41, 95% CI -29.47 to 0.65), stiffness (one study, N = 23; MD -12.72, 95% CI -26.90 to 1.46), and all-cause withdrawal (three studies, N = 77; RR 0.72, 95% CI -0.17 to 3.11). Adverse events reported for the three studies included one anxiety attack at the first session of WBV and one dropout from the comparison group ("other exercise group") due to an injury that was not related to the program. No studies reported on physical function.

AUTHORS' CONCLUSIONS

Whether WBV or WBV in addition to mixed exercise is superior to control or another intervention for women with fibromyalgia remains uncertain. The quality of evidence is very low owing to imprecision (few study participants and wide confidence intervals) and issues related to risk of bias. These trials did not measure major outcomes such as pain intensity, stiffness, fatigue, and physical function. Overall, studies were few and were very small, which prevented meaningful estimates of harms and definitive conclusions about WBV safety.

The effects of Nordic Walking training on selected upper-body muscle groups in female-office workers: A randomized trial

BACKGROUND

Regular Nordic Walking training could improve fitness and reduce tenderness in selected muscle groups in office workers.

OBJECTIVE

An assessment of the effects of a 12-week Nordic Walking training program on the perceived pain threshold (PPT) and the flexibility of selected upper-body muscle groups in postmenopausal female office workers.

METHODS

39 office workers were selected at random for the treatment group (NWg, n = 20) and the control group (Cg, n = 19). The persons from the NW group completed a 12-week Nordic Walking training program (3 times a week/1 hour). PPTs measurements in selected muscles and functional tests evaluating upper-body flexibility (Back Scratch - BS) were carried out twice in every participant of the study: before and after the training program.

RESULTS

A significant increase in PPT (kg/cm2) was observed in the following muscles in the NW group only: upper trapezius (from 1,32 kg/cm2 to 1,99 kg/cm2), mid trapezius (from 2,92 kg/cm2 to 3,30 kg/cm2), latissimus dorsi (from 1,66 kg/cm2 to 2,21 kg/cm2) and infraspinatus (from 1,63 kg/cm2 to 2,93 kg/cm2). Moreover, a significant improvement in the BS test was noted in the NW group compared with the control group (from -1,16±5,7 cm to 2,18±5,1 cm in the NW group vs from -2,52±6,1 to -2,92±6,2 in the control group).

CONCLUSIONS

A 12-week Nordic Walking training routine improves shoulder mobility and reduces tenderness in the following muscles: trapezius pars descendens and middle trapezius, infraspinatus and latissimus dorsi, in female office workers.

Aerobic exercise training for adults with fibromyalgia

BACKGROUND

Exercise training is commonly recommended for individuals with fibromyalgia. This review is one of a series of reviews about exercise training for people with fibromyalgia that will replace the "Exercise for treating fibromyalgia syndrome" review first published in 2002.

OBJECTIVES

• To evaluate the benefits and harms of aerobic exercise training for adults with fibromyalgia• To assess the following specific comparisons ० Aerobic versus control conditions (eg, treatment as usual, wait list control, physical activity as usual) ० Aerobic versus aerobic interventions (eg, running vs brisk walking) ० Aerobic versus non-exercise interventions (eg, medications, education) We did not assess specific comparisons involving aerobic exercise versus other exercise interventions (eg, resistance exercise, aquatic exercise, flexibility exercise, mixed exercise). Other systematic reviews have examined or will examine these comparisons (Bidonde 2014; Busch 2013).

SEARCH METHODS

We searched the Cochrane Library, MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Physiotherapy Evidence Database (PEDro), Thesis and Dissertation Abstracts, the Allied and Complementary Medicine Database (AMED), the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), and the ClinicalTrials.gov registry up to June 2016, unrestricted by language, and we reviewed the reference lists of retrieved trials to identify potentially relevant trials.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in adults with a diagnosis of fibromyalgia that compared aerobic training interventions (dynamic physical activity that increases breathing and heart rate to submaximal levels for a prolonged period) versus no exercise or another intervention. Major outcomes were health-related quality of life (HRQL), pain intensity, stiffness, fatigue, physical function, withdrawals, and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, extracted data, performed a risk of bias assessment, and assessed the quality of the body of evidence for major outcomes using the GRADE approach. We used a 15% threshold for calculation of clinically relevant differences between groups.

MAIN RESULTS

We included 13 RCTs (839 people). Studies were at risk of selection, performance, and detection bias (owing to lack of blinding for self-reported outcomes) and had low risk of attrition and reporting bias. We prioritized the findings when aerobic exercise was compared with no exercise control and present them fully here.Eight trials (with 456 participants) provided low-quality evidence for pain intensity, fatigue, stiffness, and physical function; and moderate-quality evidence for withdrawals and HRQL at completion of the intervention (6 to 24 weeks). With the exception of withdrawals and adverse events, major outcome measures were self-reported and were expressed on a 0 to 100 scale (lower values are best, negative mean differences (MDs)/standardized mean differences (SMDs) indicate improvement). Effects for aerobic exercise versus control were as follows: HRQL: mean 56.08; five studies; N = 372; MD -7.89, 95% CI -13.23 to -2.55; absolute improvement of 8% (3% to 13%) and relative improvement of 15% (5% to 24%); pain intensity: mean 65.31; six studies; N = 351; MD -11.06, 95% CI -18.34 to -3.77; absolute improvement of 11% (95% CI 4% to 18%) and relative improvement of 18% (7% to 30%); stiffness: mean 69; one study; N = 143; MD -7.96, 95% CI -14.95 to -0.97; absolute difference in improvement of 8% (1% to 15%) and relative change in improvement of 11.4% (21.4% to 1.4%); physical function: mean 38.32; three studies; N = 246; MD -10.16, 95% CI -15.39 to -4.94; absolute change in improvement of 10% (15% to 5%) and relative change in improvement of 21.9% (33% to 11%); and fatigue: mean 68; three studies; N = 286; MD -6.48, 95% CI -14.33 to 1.38; absolute change in improvement of 6% (12% improvement to 0.3% worse) and relative change in improvement of 8% (16% improvement to 0.4% worse). Pooled analysis resulted in a risk ratio (RR) of moderate quality for withdrawals (17 per 100 and 20 per 100 in control and intervention groups, respectively; eight studies; N = 456; RR 1.25, 95%CI 0.89 to 1.77; absolute change of 5% more withdrawals with exercise (3% fewer to 12% more).Three trials provided low-quality evidence on long-term effects (24 to 208 weeks post intervention) and reported that benefits for pain and function persisted but did not for HRQL or fatigue. Withdrawals were similar, and investigators did not assess stiffness and adverse events.We are uncertain about the effects of one aerobic intervention versus another, as the evidence was of low to very low quality and was derived from single trials only, precluding meta-analyses. Similarly, we are uncertain of the effects of aerobic exercise over active controls (ie, education, three studies; stress management training, one study; medication, one study) owing to evidence of low to very low quality provided by single trials. Most studies did not measure adverse events; thus we are uncertain about the risk of adverse events associated with aerobic exercise.

AUTHORS' CONCLUSIONS

When compared with control, moderate-quality evidence indicates that aerobic exercise probably improves HRQL and all-cause withdrawal, and low-quality evidence suggests that aerobic exercise may slightly decrease pain intensity, may slightly improve physical function, and may lead to little difference in fatigue and stiffness. Three of the reported outcomes reached clinical significance (HRQL, physical function, and pain). Long-term effects of aerobic exercise may include little or no difference in pain, physical function, and all-cause withdrawal, and we are uncertain about long-term effects on remaining outcomes. We downgraded the evidence owing to the small number of included trials and participants across trials, and because of issues related to unclear and high risks of bias (performance, selection, and detection biases). Aerobic exercise appears to be well tolerated (similar withdrawal rates across groups), although evidence on adverse events is scarce, so we are uncertain about its safety.

Influence of exercise on visceral pain: an explorative study in healthy volunteers

Background and objectives

Contradictory results have been found about the effect of different exercise modalities on pain. The aim of this study was to investigate the early effects of aerobic and isometric exercise on different types of experimental pain, including visceral pain, compared to an active control condition.

Methods

Fifteen healthy subjects (6 women, mean [standard deviation] age 25 [6.5] years) completed 3 interventions consisting of 20 minutes of aerobic cycling, 12 minutes of isometric knee extension and a deep breathing procedure as active control. At baseline and after each intervention, psychophysical tests were performed, including electrical stimulation of the esophagus, pressure pain thresholds and the cold pressor test as a measure for conditioned pain modulation. Participants completed the Medical Outcome Study Short-Form 36 and State-Trait Anxiety Inventory prior to the experiments. Data were analyzed using two-way repeated measures analysis of variance.

Results

No significant differences were found for the psychophysical tests after the interventions, compared to baseline pain tests and the control condition.

Conclusion

No hypoalgesic effect of aerobic and isometric exercise was found. The evidence for exercise-induced hypoalgesia appears to be not as consistent as initially thought, and caution is recommended when interpreting the effects of exercise on pain.

Exercise Strengthens Central Nervous System Modulation of Pain in Fibromyalgia

To begin to elucidate the mechanisms underlying the benefits of exercise for chronic pain, we assessed the influence of exercise on brain responses to pain in fibromyalgia (FM). Complete data were collected for nine female FM patients and nine pain-free controls (CO) who underwent two functional neuroimaging scans, following exercise (EX) and following quiet rest (QR). Brain responses and pain ratings to noxious heat stimuli were compared within and between groups. For pain ratings, there was a significant (p < 0.05) Condition by Run interaction characterized by moderately lower pain ratings post EX compared to QR (d = 0.39–0.41) for FM but similar to ratings in CO (d = 0.10–0.26), thereby demonstrating that exercise decreased pain sensitivity in FM patients to a level that was analogous to pain-free controls. Brain responses demonstrated a significant within-group difference in FM patients, characterized by less brain activity bilaterally in the anterior insula following QR as compared to EX. There was also a significant Group by Condition interaction with FM patients showing less activity in the left dorsolateral prefrontal cortex following QR as compared to post-EX and CO following both conditions. These results suggest that exercise appeared to stimulate brain regions involved in descending pain inhibition in FM patients, decreasing their sensitivity to pain. Thus, exercise may benefit patients with FM via improving the functional capacity of the pain modulatory system.

Intensity thresholds for aerobic exercise-induced hypoalgesia

INTRODUCTION

Despite many studies investigating exercise-induced hypoalgesia, there is limited understanding of the optimal intensity of aerobic exercise in producing hypoalgesic effects across different types of pain stimuli. Given that not all individuals are willing or capable of engaging in high-intensity aerobic exercise, whether moderate-intensity aerobic exercise (MAE) is associated with a hypoalgesic response and whether this response generalizes to multiple pain induction techniques needs to be substantiated.

PURPOSE

This study's purpose is to test for differences in the magnitude of pressure and heat pain modulation induced by MAE and vigorous-intensity aerobic exercise (VAE).

METHODS

Twelve healthy young males and 15 females completed one training session and three testing sessions consisting of 25 min of 1) stationary cycling at 70% HR reserve, 2) stationary cycling at 50% HR reserve, or 3) quiet rest (control). Pain testing was conducted on both forearms before and immediately after each condition and included the following tests: pressure pain thresholds, suprathreshold pressure pain test, static continuous heat test, and repetitive pulse heat pain test. Repeated-measures ANOVA was conducted on each pain measure.

RESULTS

VAE and MAE reduced pain ratings during static continuous heat stimuli and repetitive heat pulse stimuli, with VAE producing larger effects. VAE also increased pressure pain thresholds, whereas neither exercise influenced suprathreshold pressure pain ratings.

CONCLUSION

These results suggest that MAE is capable of producing a hypoalgesic effect using continuous and repetitive pulse heat stimuli. However, a dose-response effect was evident as VAE produced larger effects than MAE.

Aquatic exercise training for fibromyalgia

BACKGROUND

Exercise training is commonly recommended for individuals with fibromyalgia. This review examined the effects of supervised group aquatic training programs (led by an instructor). We defined aquatic training as exercising in a pool while standing at waist, chest, or shoulder depth. This review is part of the update of the 'Exercise for treating fibromyalgia syndrome' review first published in 2002, and previously updated in 2007.

OBJECTIVES

The objective of this systematic review was to evaluate the benefits and harms of aquatic exercise training in adults with fibromyalgia.

SEARCH METHODS

We searched The Cochrane Library 2013, Issue 2 (Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, Health Technology Assessment Database, NHS Economic Evaluation Database), MEDLINE, EMBASE, CINAHL, PEDro, Dissertation Abstracts, WHO international Clinical Trials Registry Platform, and AMED, as well as other sources (i.e., reference lists from key journals, identified articles, meta-analyses, and reviews of all types of treatment for fibromyalgia) from inception to October 2013. Using Cochrane methods, we screened citations, abstracts, and full-text articles. Subsequently, we identified aquatic exercise training studies.

SELECTION CRITERIA

Selection criteria were: a) full-text publication of a randomized controlled trial (RCT) in adults diagnosed with fibromyalgia based on published criteria, and b) between-group data for an aquatic intervention and a control or other intervention. We excluded studies if exercise in water was less than 50% of the full intervention.

DATA COLLECTION AND ANALYSIS

We independently assessed risk of bias and extracted data (24 outcomes), of which we designated seven as major outcomes: multidimensional function, self reported physical function, pain, stiffness, muscle strength, submaximal cardiorespiratory function, withdrawal rates and adverse effects. We resolved discordance through discussion. We evaluated interventions using mean differences (MD) or standardized mean differences (SMD) and 95% confidence intervals (95% CI). Where two or more studies provided data for an outcome, we carried out meta-analysis. In addition, we set and used a 15% threshold for calculation of clinically relevant differences.

MAIN RESULTS

We included 16 aquatic exercise training studies (N = 881; 866 women and 15 men). Nine studies compared aquatic exercise to control, five studies compared aquatic to land-based exercise, and two compared aquatic exercise to a different aquatic exercise program.We rated the risk of bias related to random sequence generation (selection bias), incomplete outcome data (attrition bias), selective reporting (reporting bias), blinding of outcome assessors (detection bias), and other bias as low. We rated blinding of participants and personnel (selection and performance bias) and allocation concealment (selection bias) as low risk and unclear. The assessment of the evidence showed limitations related to imprecision, high statistical heterogeneity, and wide confidence intervals. Aquatic versus controlWe found statistically significant improvements (P value < 0.05) in all of the major outcomes. Based on a 100-point scale, multidimensional function improved by six units (MD -5.97, 95% CI -9.06 to -2.88; number needed to treat (NNT) 5, 95% CI 3 to 9), self reported physical function by four units (MD -4.35, 95% CI -7.77 to -0.94; NNT 6, 95% CI 3 to 22), pain by seven units (MD -6.59, 95% CI -10.71 to -2.48; NNT 5, 95% CI 3 to 8), and stiffness by 18 units (MD -18.34, 95% CI -35.75 to -0.93; NNT 3, 95% CI 2 to 24) more in the aquatic than the control groups. The SMD for muscle strength as measured by knee extension and hand grip was 0.63 standard deviations higher compared to the control group (SMD 0.63, 95% CI 0.20 to 1.05; NNT 4, 95% CI 3 to 12) and cardiovascular submaximal function improved by 37 meters on six-minute walk test (95% CI 4.14 to 69.92). Only two major outcomes, stiffness and muscle strength, met the 15% threshold for clinical relevance (improved by 27% and 37% respectively). Withdrawals were similar in the aquatic and control groups and adverse effects were poorly reported, with no serious adverse effects reported. Aquatic versus land-basedThere were no statistically significant differences between interventions for multidimensional function, self reported physical function, pain or stiffness: 0.91 units (95% CI -4.01 to 5.83), -5.85 units (95% CI -12.33 to 0.63), -0.75 units (95% CI -10.72 to 9.23), and two units (95% CI -8.88 to 1.28) respectively (all based on a 100-point scale), or in submaximal cardiorespiratory function (three seconds on a 100-meter walk test, 95% CI -1.77 to 7.77). We found a statistically significant difference between interventions for strength, favoring land-based training (2.40 kilo pascals grip strength, 95% CI 4.52 to 0.28). None of the outcomes in the aquatic versus land comparison reached clinically relevant differences of 15%. Withdrawals were similar in the aquatic and land groups and adverse effects were poorly reported, with no serious adverse effects in either group. Aquatic versus aquatic (Ai Chi versus stretching in the water, exercise in pool water versus exercise in sea water)Among the major outcomes the only statistically significant difference between interventions was for stiffness, favoring Ai Chi (1.00 on a 100-point scale, 95% CI 0.31 to 1.69).

AUTHORS' CONCLUSIONS

Low to moderate quality evidence relative to control suggests that aquatic training is beneficial for improving wellness, symptoms, and fitness in adults with fibromyalgia. Very low to low quality evidence suggests that there are benefits of aquatic and land-based exercise, except in muscle strength (very low quality evidence favoring land). No serious adverse effects were reported.

Does exercise induce hypoalgesia through conditioned pain modulation?

Pain sensitivity decreases with exercise. The mechanisms that underlie this exercise-induced hypoalgesia (EIH) are unclear. Our purpose was to investigate conditioned pain modulation (CPM) as a potential mechanism of EIH. Sixteen women completed pain testing during three sessions: painful exercise, nonpainful exercise, and quiet rest. Intensity and unpleasantness ratings to noxious heat stimuli were assessed at baseline and during and following each session. Results showed that pain sensitivity decreased significantly during both exercise sessions (p < .05), but not during quiet rest. Effect size calculations showed that the size of the hypoalgesic response was greater following painful exercise than nonpainful exercise. Our results suggest that exercise-induced muscle pain may contribute to the magnitude of EIH. However, as pain sensitivity also decreased following nonpainful exercise, CPM is not likely the primary mechanism of EIH.

Prior eccentric exercise augments muscle pain and perception of effort during cycling exercise

OBJECTIVES

This study examined the effects of exercise-induced muscle damage (EIMD) on the physiological and perceptual responses to 30 minutes of submaximal cycling at 60% of oxygen consumption (VO2 peak).

METHODS

Ten participants completed two 30-minute bouts of cycling, one before and one 48 hours after performance of strenuous (24 contractions with 120% of concentric 1-repeition maximum) eccentric exercise.

RESULTS

Eccentric exercise resulted in a significant delayed-onset muscle pain (1.6±1.6 mm to 44.8±20 mm on a 100-mm visual analog scale; P<0.001) and a 15% (P<0.001) reduction in maximal strength 48 hours after exercise. Ratings of quadriceps muscle pain (1.99±0.42 vs. 3.30±0.56; P=0.003) and perceived exertion (RPE; 13.0±0.30 vs. 13.8±0.61; P=0.02) were elevated during cycling after EIMD at identical work rates. No changes were observed in VO2 (29.6±4.6 vs. 30.2±4.4 mL/kg/min; P=0.41), heart rate (154±15 vs. 155±9 beats/min; P=0.58), and ventilation (57.2±12.1 vs. 59.8±12.7 L/min; P=0.13) during exercise after EIMD. The mean change in RPE was significantly correlated (r=0.56; P<0.01) with the change in muscle pain during cycling and delayed-onset pain during resistance exercise (r=0.86; P<0.01), but did not correlate with changes in VO2, heart rate, ventilation, and maximal strength.

DISCUSSION

These findings indicate the elevations in RPE after EIMD are likely a consequence of the EIMD with the most likely explanation being an increase in localized pain before and during cycling exercise.

Pain mediates the association between physical activity and the impact of fibromyalgia on daily function

This study quantified the association between recreational physical activity and daily function in women with fibromyalgia, and determined if this association is mediated by symptoms of pain, depression, or body mass. Twenty-three women diagnosed with fibromyalgia participated in an observational survey study. Recreational physical activity and the impact of fibromyalgia on daily function were assessed using the sport and leisure time physical activity subscales of the Baecke Physical Activity Questionnaire (BPAQ) and the Fibromyalgia Impact Questionnaire (FIQ), respectively. Potential mediators of the association between physical activity and daily function were assessed using the Visual Analogue Scale for pain intensity (VAS-Pain), the Beck Depression Inventory (BDI), and body mass index (BMI). BPAQ was inversely associated with FIQ (R (2) = 0.20) and VAS-Pain (R (2) = 0.39). VAS-Pain was positively associated with FIQ (R (2) = 0.23). The inverse association between BPAQ and FIQ was no longer significant after controlling for VAS-Pain. BDI was positively associated with FIQ (R (2) = 0.37), whereas BMI was not. BPAQ was not significantly associated with either BDI or BMI. These results indicate that the intensity of musculoskeletal pain, rather than depressive symptoms or body mass, mediates the association between physical activity and daily function among women with fibromyalgia.

Transcutaneous electrical nerve stimulation reduces pain, fatigue and hyperalgesia while restoring central inhibition in primary fibromyalgia

Because transcutaneous electrical nerve stimulation (TENS) works by reducing central excitability and activating central inhibition pathways, we tested the hypothesis that TENS would reduce pain and fatigue and improve function and hyperalgesia in people with fibromyalgia who have enhanced central excitability and reduced inhibition. The current study used a double-blinded randomized, placebo-controlled cross-over design to test the effects of a single treatment of TENS with people with fibromyalgia. Three treatments were assessed in random order: active TENS, placebo TENS and no TENS. The following measures were assessed before and after each TENS treatment: pain and fatigue at rest and in movement; pressure pain thresholds, 6-m walk test, range of motion; 5-time sit-to-stand test, and single-leg stance. Conditioned pain modulation was completed at the end of testing. There was a significant decrease in pain and fatigue with movement for active TENS compared to placebo and no TENS. Pressure pain thresholds increased at the site of TENS (spine) and outside the site of TENS (leg) when compared to placebo TENS or no TENS. During active TENS, conditioned pain modulation was significantly stronger compared to placebo TENS and no TENS. No changes in functional tasks were observed with TENS. Thus, the current study suggests TENS has short-term efficacy in relieving symptoms of fibromyalgia while the stimulator is active. Future clinical trials should examine the effects of repeated daily delivery of TENS, similar to the way in which TENS is used clinically on pain, fatigue, function, and quality of life in individuals with fibromyalgia.