Effects of Exercise-induced Hypoalgesia and Its Neural Mechanisms

Aerobic exercise to alleviate primary dysmenorrhea in adolescents and young women: A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Aerobic exercise has been confirmed to alleviate primary dysmenorrhea (PD) in adolescents and young women. However, the effect of the aerobic exercise type and dosage on PD alleviation was unclear. This research aims to assess the effect of aerobic exercise on PD and investigate the dose-response relationships.

MATERIAL AND METHODS

Systematic literature searches of Web of Science, Embass, Cochrane Library, PubMed, PsycNET, CINAHL, CNKI, Baidu Scholar, Google Scholar, and other Complimentary Medicine Database. PICOS standards were adopted in this research: participants were nonathlete women with PD; intervention was aerobic exercise of at least one menstruation cycle; comparator was any comparator; outcomes were pain intensity or pain duration; and study type was randomized controlled trials. The Cochrane Collaboration risk of bias tool was used to assess the quality of the research. Random-effect meta-analysis was conducted for pain intensity and pain duration, with prespecified subgroup analyses based on aerobic exercise components. The strength of the evidence was assessed using GRADE. This systematic review and meta-analysis was registered in PROSPERO (CRD42024533544).

RESULTS

The study identified 16 eligible studies, with 15 involving adolescents, totaling 918 participants aged 15 to 43, with an average age of 21.26 ± 13.15. The results confirmed that aerobic exercise can alleviate PD's pain intensity (standard mean difference (SMD) = -1.728 (p = 0.00), 95% CI [-2.26 to -1.31]) and pain duration (weighted mean difference (WMD) = -12.53 h, p = 0.01, 95% CI: -21.38 to -3.68). However, the heterogeneity of these two results was high. Subgroup analysis showed that Pilates (SMD = -3.17, 95% CI [-4.26 to -2.07]), low intensity (SMD = -1.64, 95% CI [-2.10 to -1.19]), 31-45 min duration (SMD = -3.05, 95% CI [-5.36 to -0.75]), ≤2 times per week frequency (SMD = -2.24, 95% CI [-3.36 to -1.12]), and a period cycle of 2 menstrual cycles (SMD = -2.21, 95% CI [-3.13 to -1.28]) had the maximum effect size.

CONCLUSIONS

Aerobic exercise was able to alleviate pain intensity and pain duration in adolescents and young women with PD. Moderate-quality evidence indicates that Pilates, low intensity, 46-60 min, ≤two times per week, or two menstrual cycles showed more efficiency in alleviating PD. Due to the limited data, future research should prioritize conducting randomized controlled trials of aerobic exercise interventions in younger age groups to develop personalized treatment strategies for adolescents.

The effect of stretching intensity on pain sensitivity: A randomized crossover study on healthy adults

BACKGROUND

Stretching exercises have effects on local and widespread pain sensitivity. A dose-response relationship may exist between the analgesic effect and the intensity of stretching, such that a higher intensity of stretching may generate a larger reduction in analgesic response, but this remains to be studied. This study aimed to examine the dose-response relationship between stretching intensity and the analgesic effect.

METHODS

A randomized, repeated-measures crossover study was performed to examine the effect of stretching to the first point of pain onset and stretching to the point of a sensation of stretching (discomfort). The primary outcome was regional and distant pressure pain thresholds.

RESULTS

Thirty-one participants (n = 24 female) were available for analysis. We observed a 22.2% increase in regional pressure pain thresholds (93.2 kPa, p = 0.001) and a 15.0% increase in distant pressure pain thresholds (50.9 kPa, p = 0.012) following stretching to the point of stretch. We observed a 20.0% increase in regional pressure pain thresholds (90.3 kPa, p = 0.001) and a 15.1% increase in distant pressure pain thresholds (52.1 kPa, p = 0.004) following stretching to the point of pain.

CONCLUSIONS

The results showed that local and widespread pain sensitivity decreased following acute stretching, regardless of stretching intensity. No differences in pain sensitivity were found between stretching to the point of stretch or stretching to the first onset of pain. Thus, the results showed no evidence of a dose-response relationship between stretching intensity and the analgesic effect.

SIGNIFICANCE

The study showed a significant acute hypoalgesic effect of stretching exercises regardless of stretching intensity. This may have appropriate clinical implications for patients with musculoskeletal and nociplastic pain.

Opposite effects of isometric exercise on pain sensitivity of healthy individuals: the role of pain modulation

Introduction

Exercise-induced hypoalgesia (EIHypo) among healthy individuals is well documented; however, the opposite effect of exercise, ie, exercise-induced hyperalgesia (EIHyper), has mainly been described in patients with chronic pain or after intense/painful exercise.

Objectives

We investigated the extent to which EIHypo and/or EIHyper occur among healthy participants and whether these responses are associated with individuals' pain modulation capacity.

Methods

Fifty-seven participants (mean age 29.20 ± 5.21 years) underwent testing of pressure pain threshold as an index of EIHypo/EIHyper: pain adaptation, offset analgesia (OA), and conditioned pain modulation as indices of pain modulation, prior to and immediately postsubmaximal isometric exercise (n = 40) or rest (n = 17, control group). Body awareness and exercise-evoked stress were also evaluated. Test-retest repeatability of the pain modulation indices was performed as well.

Results

Twenty-four participants (60%) exhibited EIHypo, whereas 16 (40%) exhibited EIHyper. Pressure pain threshold did not change in the control group. Baseline (preexercise) OA efficacy predicted EIHypo/EIHyper. Furthermore, OA significantly decreased postexercise in the EIHyper subgroup and slightly increased in the EIHypo subgroup. Exercise-induced hypoalgesia was associated with magnitude of daily exercise while EIHyper was associated with increased exercise-evoked stress and body awareness.

Conclusion

Submaximal isometric exercise can induce opposite effects on pain sensitivity among healthy participants-EIHypo or EIHyper. Descending pain inhibition pathways, and top-down influences over these pathways, seem to be involved in EIHypo/EIHyper effects. As such isometric exercise is often preferred in early stages of rehabilitation, preliminary screening individuals' vulnerability to this exercise is important; OA test may be used for this purpose.

Navigating the Global Landscape of Exercise Interventions for Knee Osteoarthritis: Exploring Evolving Trends and Emerging Frontiers From a Bibliometric and Visualization Analysis Perspective (2011-2022)

OBJECTIVES

This study utilizes visual analysis methods to retrospectively examine the evolution and trends in exercise interventions for knee osteoarthritis (KOA) research from 2011 to 2022.

DESIGN

Bibliometric and visualization analysis review.

SETTING AND PARTICIPANTS

Using the Web of Science database, the literature search range is from January 1, 2011, to December 31, 2022, with the language specified as English and document type set to Article.

METHODS

Visual analysis was used to analyze literature in the field of exercise interventions for KOA, with KOA and exercise interventions as the key search terms. Visualization maps for countries/regions were created using Tableau and Scimago Graphica software. Institutional, author, and keyword visualization maps were drawn using CiteSpace and VOSviewer software.

RESULTS

In total, 3137 articles were included in the visual analysis. The United States emerged as the leading country in terms of publication volume and contribution. Moreover, developed countries such as the United States, Australia, United Kingdom, and Canada have established close and stable cooperative relationships. The University of Melbourne stood out as the institution with both the highest publication volume and centrality. At the forefront of research output in this field was Bennell K.L. from the University of Melbourne. The journal with the highest co-citation frequency was Osteoarthritis and Cartilage. The keyword clustering map highlighted an evolution in the field of exercise interventions for KOA, emphasizing 8 key research themes spanning knee osteoarthritis, serum cartilage, osteoarthritis initiative, patellofemoral pain, total knee arthroplasty, exercise-induced hypoalgesia, isometric exercise, and anterior cruciate ligament reconstruction. Burst analysis revealed that older adult was the earliest and most prominent keyword, with contemporary topics such as patellofemoral pain, safety, musculoskeletal disorder, and neuromuscular exercise considered as research hotspots and future directions in this field.

CONCLUSIONS AND IMPLICATIONS

The global attention on exercise interventions for KOA research is expanding, emphasizing the importance of strengthened connections among developing countries and collaborative author groups. Recent trends have shifted toward topics such as neuromuscular training, treatment safety, and musculoskeletal disorders, whereas research interest in patellofemoral pain remains unabated. Neuromuscular training for KOA represents the current frontier in this field. Future research should delve into the effects of diverse types of exercise interventions for KOA on neuromuscular injury and recovery, exploring feasibility and safety to formulate personalized exercise plans for patients with KOA.

Analgesic effect of dance movement therapy: An fNIRS study

OBJECTIVE

This study aims to explores the physiological and psychological mechanisms of exercise-induced hypoalgesia (EIH) by combining the behavioral results with neuroimaging data on changes oxy-hemoglobin (HbO) in prefrontal cortex (PFC).

METHODS

A total of 97 healthy participants were recruited and randomly divided into three groups: a single dance movement therapy (DMT) group, a double DMT group, and control group. Evaluation indicators included the pressure pain threshold (PPT) test, the color-word stroop task (CWST) for wearing functional near-infrared spectroscopy (fNIRS), and the self-assessment manikin (SAM). The testing time is before intervention, after intervention, and one hour of sit rest after intervention.

RESULTS

1) Repeated measures ANOVA revealed that, there is a time * group effect on the PPT values of the three groups of participants at three time points. After 30 min of acute dance intervention, an increase in the PPT values of 10 test points occurred in the entire body of the participants in the experimental group with a significant difference than the control group. 2) In terms of fNIRS signals, bilateral DLPFC and left VLPFC channels were significantly activated in the experimental group. 3) DMT significantly awakened participants and brought about pleasant emotions, but cognitive improvement was insignificant. 4) Mediation effect analysis found that the change in HbO concentration in DLPFC may be a mediator in predicting the degree of improvement in pressure pain threshold through dance intervention (total effect β = 0.7140).

CONCLUSION

In healthy adults, DMT can produce a diffuse EIH effect on improving pressure pain threshold, emotional experience but only showing an improvement trend in cognitive performance. Dance intervention significantly activates the left ventrolateral and bilateral dorsolateral prefrontal cortex. This study explores the central nervous system mechanism of EIH from a physiological and psychological perspective.

Hypoalgesia and Conditioned Pain Modulation in Blood Flow Restriction Resistance Exercise

We compared the magnitude of exercise-induced hypoalgesia and conditioned pain modulation between blood-flow restriction (BFR) resistance exercise (RE) and moderate-intensity RE. Twenty-five asymptomatic participants performed unilateral leg press in two visits. For moderate-intensity RE, subjects exercised at 50% 1RM without BFR, whereas BFR RE exercised at 30% 1RM with a cuff inflated to 60% limb occlusion pressure. Exercise-induced hypoalgesia was quantified by pressure pain threshold changes before and after RE. Conditioned pain modulation was tested using cold water as the conditioning stimulus and mechanical pressure as the test stimulus and quantified as pressure pain threshold change. Difference in conditioned pain modulation pre- to post-RE was then calculated. The differences of RE on pain modulations were compared using paired t-tests. Pearson's r was used to examine the correlation between exercise-induced hypoalgesia and changes in conditioned pain modulation. We found greater hypoalgesia with BFR RE compared to moderate-intensity RE (p=0.008). Significant moderate correlations were found between exercise-induced hypoalgesia and changes in conditioned pain modulation (BFR: r=0.63, moderate-intensity: r=0.72). BFR RE has favorable effects on pain modulation in healthy adults and the magnitude of exercise-induced hypoalgesia is positively correlated with conditioned pain modulation activation.

Effect of Shoulder Movement Routine on Postoperative Shoulder Pain in Total Laparoscopic Hysterectomy: A Randomized Clinical Trial

Background and Objectives: Postoperative shoulder pain is a common issue after total laparoscopic hysterectomy (TLH). This study evaluated the impact of a shoulder movement routine on postoperative shoulder pain in women undergoing uncomplicated TLH. Materials and Methods: An open-label randomized clinical trial included women without prior shoulder pain undergoing TLH between 20 January and 20 March 2024. Participants were randomized into two groups: Group 1 (n = 36) received a shoulder movement routine, while Group 2 (control, n = 39) performed a hand movement routine. Shoulder pain was assessed using the visual analog scale (VAS) at 6 h, 24 h, and 7 days postoperatively. Results: Seventy-five women participated. No significant differences were found between the groups regarding demographic variables, surgery duration, or hospital stay. Shoulder pain scores (VAS) at three time points (6 h, 24 h, and 7 days) showed no significant differences between groups (p = 0.57, p = 0.69, and p = 0.91, respectively). Similarly, there were no significant differences in incisional or abdominal pain. Conclusions: The shoulder movement routine did not significantly reduce postoperative shoulder pain in women undergoing uncomplicated TLH.

The interactive effects of different exercises and hawthorn consumption on the pain threshold of TMT-induced Alzheimer male rats

Exercise increases the pain threshold in healthy people. However, the pain threshold modulation effect of exercise and hawthorn is unclear because of its potential benefits in people with persistent pain, including those with Alzheimer's disease. Accordingly, after the induction of Alzheimer's disease by trimethyl chloride, male rats with Alzheimer's disease were subjected to a 12-week training regimen consisting of resistance training, swimming endurance exercises, and combined exercises. In addition, hawthorn extract was orally administered to the rats. Then, their pain threshold was evaluated using three Tail-flick, Hot-plate, and Formalin tests. Our results showed that Alzheimer's decreased the pain threshold in all three behavioral tests. Combined exercise with hawthorn consumption had the most statistically significant effect on Alzheimer's male rats' pain threshold in all three experiments. A combination of swimming endurance and resistance exercises with hawthorn consumption may modulate hyperalgesia in Alzheimer's rats. Future studies need to determine the effects of these factors on the treatment and/or management of painful conditions.

Quality of life and level of physical activity of individuals with temporomandibular disorders with and without otological symptoms: Secondary analysis of a cross-sectional study

BACKGROUND AND PURPOSE

Otological symptoms (OS) are highly prevalent in individuals with temporomandibular disorders (TMD). Individuals with TMD and OS have more neck disability and decreased deep neck muscles endurance when compared to individuals without OS. However, no studies have evaluated whether OS is associated with lower Quality of Life (QoL) and worse levels of physical activity. This study aimed to evaluate the QoL and level of physical activity of individuals with TMD with and without OS.

METHODS

In this cross-sectional study, 62 individuals with TMD were allocated into 2 groups: TMD with OS (n = 36) or TMD without OS (n = 26). Self-reported complaints of dizziness, vertigo, tinnitus, earache, ear fullness, or hypoacusis were considered as OS. QoL was assessed with the WHOQOL-Bref and physical activity with the IPAQ-SF. Independent t-test and chi-squared test were used for analysis between-groups. Effect sizes were reported using Cohen's d. A Pearson correlation was used to compare the number of OS and QoL scores. A significance level of p < 0.05% and 95% confidence intervals were considered statistically significant.

RESULTS

The total generic scores for QoL were not different between-groups (p = 0.076), but individuals with TMD with OS had lower satisfaction (p = 0.015; d: 0.63) and physical domain (p = 0.015; d: 0.64) scores with a moderate effect size. In TMD with OS, 69.4% of individuals were irregularly active and 50% for the TMD without OS, with no statistical significance (p > 0.05). The number of OSs was inversely and weakly associated with the QoL total score.

CONCLUSION

Individuals with TMD and OS are associated with worsened QoL (physical domain and satisfaction) when compared to individuals with TMD without OS. The higher the number of OS, the worse the QoL score. Individuals with TMD with and without OS had similar levels of physical activity, but a high prevalence of irregularly active and sedentary individuals within TMD diagnosed population was found.

Hypoalgesia after aerobic exercise in healthy subjects: A systematic review and meta-analysis

Exercise-Induced Hypoalgesia (EIH) refers to an acute reduced pain perception after exercise. This systematic review and meta-analysis investigated the effect of a single aerobic exercise session on local and remote EIH in healthy individuals, examining the role of exercise duration, intensity, and modality. Pressure pain thresholds (PPT) are used as the main measure, applying the Cochrane risk of bias tool and GRADE approach for certainty of evidence assessment. Mean differences (MD; Newton/cm²) for EIH effects were analysed. Thirteen studies with 23 exercises and 14 control interventions are included (498 participants). Most studies used bicycling, with only two including running/walking and one including rowing. EIH occurred both locally (MD = 3.1) and remotely (MD = 1.8), with high-intensity exercise having the largest effect (local: MD = 7.5; remote: MD = 3.0) followed by moderate intensity (local: MD = 3.1; remote: MD = 3.0). Low-intensity exercise had minimal impact. Neither long nor short exercise duration induced EIH. Bicycling was found to be effective in eliciting EIH, in contrast to the limited research observed in other modalities. The overall evidence quality was moderate with many studies showing unclear risk biases.

Changes in Hip and Knee Strength Are Not Associated With Improved Clinical Outcomes After Rehabilitation in Individuals With Patellofemoral Pain: A Critically Appraised Topic

CLINICAL SCENARIO

Patellofemoral pain (PFP) is a widespread knee disorder encountered in clinical practice. Clinicians have often focused on strengthening hip and knee musculature to improve pain and disability, which are the ultimate clinical goals of PFP treatment. However, PFP literature has shown improvement in pain and disability without concurrent changes in lower-extremity strength after rehabilitation. Although some researchers have achieved a significant increase in strength after rehabilitation in PFP cohorts, there was no association with improved pain and disability. The inconsistent improvements in strength and the lack of association with clinical outcomes call for a critical appraisal of the available evidence to better understand the association between changes in hip and knee strength and improved clinical outcomes in individuals with PFP.

CLINICAL QUESTION

Are changes in hip and knee strength associated with improved pain and disability after rehabilitation in individuals with PFP?

SUMMARY OF KEY FINDINGS

Four studies met the inclusion criteria and were included in the appraisal. Following rehabilitation, one study achieved strength improvements in knee extension. One study achieved strength improvements in knee extension, but not in hip external rotation and hip abduction. Two studies did not achieve strength improvements in hip external rotation, hip abduction, hip extension, or knee extension. All included studies achieved improvements in pain or disability after rehabilitation. None of the studies found a significant association between changes in hip and knee strength (either improved or not) and improved pain and disability.

CLINICAL BOTTOM LINE

There is consistent evidence that changes in hip and knee strength are not associated with improved clinical outcomes after rehabilitation in adults with PFP.

STRENGTH OF RECOMMENDATION

Collectively, the body of evidence included is to answer the clinical question aligns with the strength of recommendation of B based on the Strength of Recommendation Taxonomy.

The influence of aggressive exercise on responses to self-perceived and others' pain

Previous studies have reported relationships between exercise and pain. However, little is known about how aggressive exercise modulates individuals' responses to their own and others' pain. This present study addresses this question by conducting 2 studies employing event-related potential (ERP). Study 1 included 38 participants whose self-perceived pain was assessed after intervention with aggressive or nonaggressive exercises. Study 2 recruited 36 participants whose responses to others' pain were assessed after intervention with aggressive or nonaggressive exercise. Study 1's results showed that P2 amplitudes were smaller, reaction times were longer, and participants' judgments were less accurate in response to self-perceived pain stimuli, especially to high-pain stimuli, after intervention with aggressive exercise compared to nonaggressive exercise. Results of study 2 showed that both P3 and LPP amplitudes to others' pain were larger after intervention with aggressive exercise than with nonaggressive exercise. These results suggest that aggressive exercise decreases individuals' self-perceived pain and increases their empathic responses to others' pain.

Neck pain and headache: Pathophysiology, treatments and future directions

INTRODUCTION

Neck pain is a prevalent neurologic and musculoskeletal complaint in the general population and is often associated with primary headache disorders such as migraine and tension-type headache (TTH). A considerable proportion, ranging from 73% to 90%, of people with migraine or TTH also experience neck pain, and there is a positive correlation between headache frequency and neck pain. Furthermore, neck pain has been identified as a risk factor for migraine and TTH. Although the exact underlying mechanisms linking neck pain to migraine and TTH remain uncertain, pain sensitivity appears to play an important role. People with migraine or TTH exhibit lower pressure pain thresholds and higher total tenderness scores compared with healthy controls.

PURPOSE

This position paper aims to provide an overview of the current evidence on the relationship between neck pain and comorbid migraine or TTH. It will encompass the clinical presentation, epidemiology, pathophysiology, and management of neck pain in the context of migraine and TTH.

IMPLICATIONS

The relationship between neck pain and comorbid migraine or TTH is incompletely understood. In the absence of robust evidence, the management of neck pain in people with migraine or TTH relies mostly on expert opinion. A multidisciplinary approach is usually preferred, involving pharmacologic and non-pharmacologic strategies. Further research is necessary to fully dissect the linkage between neck pain and comorbid migraine or TTH. This includes the development of validated assessment tools, evaluation of treatment effectiveness, and exploration of genetic, imaging, and biochemical markers that might aid in diagnosis and treatment.

Potential Local Mechanisms for Exercise-Induced Hypoalgesia in Response to Blood Flow Restriction Training

Overall, there is a great need within sports medicine to ensure that athletes can return from injury in an efficient, yet thorough manner. It is crucial to not avoid necessary difficulties in this process but also to ensure time-efficient rehabilitation. One of the more promising techniques to achieve timely recovery is blood flow restriction (BFR) training. BFR training is a growing and novel development that could be a vital tool to lighten the burden of recovery from injury in athletes. BFR utilizes a pneumatic tourniquet to limit blood flow in specific areas of the body. The use of BFR has been shown to potentially enhance the analgesic effects of exercise-induced hypoalgesia (EIH). By limiting pain, athletes will be less burdened by mobility and loading exercises required for them to effectively return to play. In a field where time away from sports can have massive implications, the need for tools to assist in the acceleration of the rehabilitation process is vital. Much of the work that has already been done in the field has been able to exploit the benefits of EIH and further enhance the body's capabilities through BFR. Studies have compared EIH at low- and high-intensity settings utilizing BFR with both resistance and aerobic exercise. The results of these studies show comparable beta-endorphin levels with high-intensity exercise without BFR and low-intensity exercise with BFR. Low-intensity training with BFR had greater local pain relief, perhaps indicating the promising effects of BFR in enhancing EIH. By reviewing the current literature on this topic, we hope that further progress can be made to better understand the mechanism behind BFR and its ability to enhance EIH. Currently, local metabolites are a major focus for the potential mechanism behind these effects. Mas-related G-protein-coupled receptors (Mrgprs) contribute to local pain pathways via mast cell degranulation. Similarly, chemokine receptor 2/chemokine ligand 2 (CCR2/CCL2) triggers mast cell degranulation and inflammation-induced pain. Finally, pain-reducing effects have been linked to anti-inflammatory IL-10 signaling and anaerobic metabolites via transient receptor potential vanilloid 1 (TRPV1). Through a better understanding of these metabolites and their mechanisms, it is possible to further exploit the use of BFR to not only serve athletes recovering from injury but also apply this information to better serve all patients.

The effect and mechanism of exercise for post-stroke pain

One of the common negative effects of a stroke that seriously lowers patients' quality of life is post-stroke pain (PSP). Thus, exercise in PSP management has become a hot research topic. The main advantages of exercise therapy are affordability and ease of acceptance by patients compared to other treatment methods. Therefore, this article reviews the effectiveness and possible mechanisms of exercise interventions for PSP. Exercise training for patients with PSP not only improves physical function but also effectively reduces pain intensity and attenuates the behavioral response to pain. In addition, exercise therapy can improve brain function and modulate levels of pro-inflammatory and neurotrophic factors to exert specific analgesic effects. Potential mechanisms for exercise intervention include modulation of synaptic plasticity in the anterior cingulate gyrus, modulation of endogenous opioids in vivo, reversal of brain-derived neurotrophic factor overexpression, inhibition of purinergic receptor (P2X4R, P2X7R) expression, and inhibition of microglia activation. However, current research on exercise for PSP remains limited, and the sustainable benefits of exercise interventions for PSP need to be further investigated.

Mechanisms of exercise for diabetic neuropathic pain

Diabetic neuropathic pain (DNP) is a common disease that affects the daily lives of diabetic patients, and its incidence rate is very high worldwide. At present, drug and exercise therapies are common treatments for DNP. Drug therapy has various side effects. In recent years, exercise therapy has received frequent research and increasing attention by many researchers. Currently, the treatment of DNP is generally symptomatic. We can better select the appropriate exercise prescription for DNP only by clarifying the exercise mechanism for its therapy. The unique pathological mechanism of DNP is still unclear and may be related to the pathological mechanism of diabetic neuropathy. In this study, the mechanisms of exercise therapy for DNP were reviewed to understand better the role of exercise therapy in treating DNP.

The effect and mechanism of traditional Chinese exercise for chronic low back pain in middle-aged and elderly patients: A systematic review

Background

Increasing lines of evidence indicate that traditional Chinese exercise (TCE) has potential benefits in improving chronic low back pain (CLBP) symptoms. To assess the clinical efficacy of TCE in the treatment of CLBP, we performed a systematic review of existing randomized controlled trials (RCTs) of CLBP and summarized the neural mechanisms underlying TCE in the treatment of CLBP.

Methods

A systematic search was conducted in four electronic databases: PubMed, Embase, the Cochrane Library, and EBSCO from January 1991 to March 2022. The quality of all included RCTs was evaluated by the Physiotherapy Evidence Database Scale (PEDro). The primary outcomes included pain severity and pain-related disability.

Results

A total of 11 RCTs with 1,256 middle-aged and elderly patients with CLBP were included. The quality of all 11 included RCTs ranged from moderate to high according to PEDro. Results suggested that TCE could considerably reduce pain intensity in patients with CLBP. Overall, most studies did not find any difference in secondary outcomes (quality of life, depression, and sleep quality).

Conclusion

The neurophysiological mechanism of TCE for treating CLBP could be linked to meditation and breathing, posture control, strength and flexibility training, and regulation of pain-related brain networks. Our systematic review showed that TCE appears to be effective in alleviating pain in patients with CLBP.

Effect of exercise intervention on social distance in middle-aged and elderly patients with chronic low back pain

Background

Increased social distance is one of the manifestations of social impairment. Chronic low back pain (CLBP) is one of factors associated with increased social distance and social withdrawal. Exercise therapy is an effective means to social impairment. However, whether exercise could reduce social distance in patients with CLBP remains unknown. This study aimed to investigate the effect of exercise on social distance in middle-aged and elderly patients with CLBP.

Methods

The longitudinal intervention recruited 29 middle-aged and elderly patients with CLBP from various communities in Yangpu District, Shanghai, China. The participants received exercise intervention for 8 weeks. The assessments were conducted before and after the intervention, including social distance, pain intensity, unpleasantness of pain, Roland-Morris Questionnaire (RMDQ), Self-Rating Anxiety Scale (SAS), and Self-Rating Depression Scale (SDS). Intention to treat analysis was performed.

Results

After the 8-week exercise intervention, the social distance of patients with CLBP was shorter than that before intervention and showed significant difference (p &lt; 0.05). The scores of pain intensity, unpleasantness of pain, RMDQ, SAS, and SDS also decreased and were significantly different between pre- and post-intervention (p &lt; 0.05). In addition, the social distance, pain intensity, unpleasantness of pain, RMDQ, SAS, and SDS scores of the moderate CLBP group decreased more after the intervention compared with those of the mild CLBP group.

Conclusion

The 8-week exercise intervention cannot only shorten the social distance in middle-aged and elderly patients with CLBP but also relieve pain, disability, and negative emotions.

Non-invasive Brain Stimulation for Central Neuropathic Pain

The research and clinical application of the noninvasive brain stimulation (NIBS) technique in the treatment of neuropathic pain (NP) are increasing. In this review article, we outline the effectiveness and limitations of the NIBS approach in treating common central neuropathic pain (CNP). This article summarizes the research progress of NIBS in the treatment of different CNPs and describes the effects and mechanisms of these methods on different CNPs. Repetitive transcranial magnetic stimulation (rTMS) analgesic research has been relatively mature and applied to a variety of CNP treatments. But the optimal stimulation targets, stimulation intensity, and stimulation time of transcranial direct current stimulation (tDCS) for each type of CNP are still difficult to identify. The analgesic mechanism of rTMS is similar to that of tDCS, both of which change cortical excitability and synaptic plasticity, regulate the release of related neurotransmitters and affect the structural and functional connections of brain regions associated with pain processing and regulation. Some deficiencies are found in current NIBS relevant studies, such as small sample size, difficulty to avoid placebo effect, and insufficient research on analgesia mechanism. Future research should gradually carry out large-scale, multicenter studies to test the stability and reliability of the analgesic effects of NIBS.

Differences and Correlations of Anxiety, Sleep Quality, and Pressure-Pain Threshold between Patients with Chronic Low Back Pain and Asymptomatic People

Background. Chronic low back pain (CLBP) is a clinically common and expensive disease. Patients frequently take sick leaves because of pain and dysfunction, and their unpleasant life and work experiences cause psychological depression and anxiety and affect their quality of life. Sleep disturbance is a common problem among patients with low back pain (LBP) with more than 50% complaining about poor sleep quality. This study aimed to explore the correlations between anxiety, sleep quality, and pressure-pain threshold (PPT) and their differences between patients with CLBP and asymptomatic people. Methods. Forty patients with CLBP and 40 asymptomatic people were recruited. Relevant data, including State-Trait Anxiety Inventory, Pittsburgh Sleep Quality Index, and PPT, were individually and independently collected by blinded physiotherapists with a practicing certificate and then statistically analyzed. An independent sample t-test was used to determine the intergroup differences between patients with CLBP and asymptomatic populations. Pearson correlation coefficient was employed for correlation analysis. Results. The CLBP group had significantly higher anxiety scores (41.64 ± 9.88 vs. 36.69 ± 8.31; t = −2.496, $p=0.015$ ) than the asymptomatic group. A significant difference was found in the total score of the Pittsburgh Sleep Quality Index (6.41 ± 2.43 vs. 5.09 ± 2.18; t = −2.628, $p=0.010$ ) but not in the trait anxiety (44.00 ± 7.83 vs. 42.67 ± 9.51; t = −0.695, $p=0.489$ ) of the two groups. State−Trait Anxiety Inventory showed a low to moderate negative correlation with PPT. No remarkable correlation was observed between Pittsburgh Sleep Quality Index and PPT. Conclusions. Patients with CLBP showed considerably worse state anxiety and sleep quality than asymptomatic people; however, no substantial difference in PPT was found between the two groups. The results suggest that in clinical practice, the focus should include pain and related social and psychological factors. CLBP treatment could be considered from multiple perspectives and disciplines.This trial is registered with Chinese Clinical Trial Registry (Trial registration: ChiCTR-TRC-13003701).

Exercise for Osteoarthritis: A Literature Review of Pathology and Mechanism

Osteoarthritis (OA) has a very high incidence worldwide and has become a very common joint disease in the elderly. Currently, the treatment methods for OA include surgery, drug therapy, and exercise therapy. In recent years, the treatment of certain diseases by exercise has received increasing research and attention. Proper exercise can improve the physiological function of various organs of the body. At present, the treatment of OA is usually symptomatic. Limited methods are available for the treatment of OA according to its pathogenesis, and effective intervention has not been developed to slow down the progress of OA from the molecular level. Only by clarifying the mechanism of exercise treatment of OA and the influence of different exercise intensities on OA patients can we choose the appropriate exercise prescription to prevent and treat OA. This review mainly expounds the mechanism that exercise alleviates the pathological changes of OA by affecting the degradation of the ECM, apoptosis, inflammatory response, autophagy, and changes of ncRNA, and summarizes the effects of different exercise types on OA patients. Finally, it is found that different exercise types, exercise intensity, exercise time and exercise frequency have different effects on OA patients. At the same time, suitable exercise prescriptions are recommended for OA patients.

The Last Decade Publications on Diabetic Peripheral Neuropathic Pain: A Bibliometric Analysis

Background

Diabetic peripheral neuropathic pain (DPNP) is a usual complication of diabetes with a high incidence and mortality. Many diabetes-related studies have been published in various journals. However, bibliometrics and visual analyses in the domain of DPNP research are still lacking. The study aimed to offer a visual method to observe the systematic overview of global research in this field from 2011 to 2021.

Methods

The publications from the Science Citation Index Expanded in Web of Science (WOS) in the past 11 years (from 2011 to 2021) were collected and sorted out, and those related to DPNP were extracted and analyzed. The article language was limited in English. Then, CiteSpace V was used for the bibliometric analysis of the extracted literature.

Results

A total of 1,422 articles met the inclusion criteria. A continuous but unstable growth in the amounts of papers published on DPNP was observed over the last 11 years. The subject sort of the 1,422 papers mainly concentrates on Endocrinology Metabolism, Clinical neurology and Neurosciences from the WOS. According to the research contribution in the field of DPNP, the United States occupies a leading position, with the highest amounts of publications, citations, open access, and the H- index.

Conclusion

This study provides a visual analysis method for the trend of DPNP, and offers some hidden serviceable information that may define new directions for future research.

Long Non-coding RNA and mRNA Expression Change in Spinal Dorsal Horn After Exercise in Neuropathic Pain Rats

Exercise can help inhibition of neuropathic pain (NP), but the related mechanism remains being explored. In this research, we performed the effect of swimming exercise on the chronic constriction injury (CCI) rats. Compared with CCI group, the mechanical withdrawal threshold of rats in the CCI-Swim group significantly increased on the 21st and 28th day after CCI surgery. Second-generation RNA-sequencing technology was employed to investigate the transcriptomes of spinal dorsal horns in the Sham, CCI, and CCI-Swim groups. On the 28th day post-operation, 306 intersecting long non-coding RNAs (lncRNAs) and 173 intersecting mRNAs were observed between the CCI vs Sham group and CCI-Swim vs CCI groups. Then, the biological functions of lncRNAs and mRNAs in the spinal dorsal horn of CCI rats were then analyzed. Taking the results together, this study could provide a novel perspective for the treatment for NP.

Correlations between Age, Pain Intensity, Disability, and Tactile Acuity in Patients with Chronic Low Back Pain

Objective

Chronic low back pain is an overwhelming problem for a wide range of people and leads to tactile acuity deficits. We aimed to investigate the correlations among age, pain severity, disability, and tactile acuity in patients with chronic low back pain by using multiple tactile acuity tests.

Methods

A total of 58 participants (36.40 ± 14.95 years) with chronic low back pain were recruited, and two-point discrimination, point-to-point test, and two-point estimation were performed on their painful low back areas. The correlations between age, pain intensity, disability, and tactile acuity were characterized with Pearson's correlation coefficients. Subgroup analyses according to the median values of age, pain intensity, and disability were used to compare the intergroup difference in tactile acuity.

Results

Results illustrated significant negative associations among age, pain intensity, disability, and tactile acuity. Subgroup analyses revealed that patients with below-the-median values of age, pain intensity, and disability had better performance in tactile acuity tests than those with above-the-median values.

Conclusion

This study indicated that tactile acuity was negatively associated with age, pain intensity, and disability in young patients with chronic low back pain.

The Effect of Mobile Care Delivery on Clinically Meaningful Outcomes, Satisfaction, and Engagement Among Physical Therapy Patients: Observational Retrospective Study

Background

Musculoskeletal care is now delivered via mobile apps as a health care benefit. Although preliminary evidence shows that the clinical outcomes of mobile musculoskeletal care are comparable with those of in-person care, no research has examined the features of app-based care that secure these outcomes.

Objective

Drawing on the literature around in-person physical therapy, this study examines how patient-provider relationships and program engagement in app-based physical therapy affect clinically meaningful improvements in pain, function, and patient satisfaction. It then evaluates the effects of patient-provider relationships forged through in-app messages or video visits and timely, direct access to care on patients’ engagement in their recovery.

Methods

We conducted an observational, retrospective study of 814 pre- and postsurveyed participants enrolled in a mobile app physical therapy program where physical therapists prescribed workouts, education, and therapeutic activities after a video evaluation from February 2019 to December 2020. We estimated generalized linear models with logit functions to evaluate the effect of program engagement on clinical outcomes, minimal clinically important differences (MCIDs) in pain (ΔVisual Analogue Scale ≤−1.5) and function (ΔPatient Specific Functional Scale ≥1.3), and the effects of patient-provider relationships and clinical outcomes on patient satisfaction—participant reported likelihood to recommend the program (Net Promoter Scores of 9-10). We estimated Poisson generalized linear models to evaluate the effects of stronger patient-provider relationships and timely access to physical therapy within 24 hours on engagement including the number of weekly workouts and weeks in the program.

Results

The odds that participants (N=814) had a pain MCID increased by 13% (odds ratio [OR] 1.13, 95% CI 1.04-1.23; P=.003) with each weekly workout and the odds of a function MCID by 4% (OR 1.04, 95% CI 1.00-1.08; P=.03) with each week in the program. Participants with MCIDs in function and large changes in pain (Δ Visual Analogue Scale ≤−3.5) were 1.85 (95% CI 1.17-2.93; P=.01) and 2.84 times (95% CI 1.68-4.78; P<.001) more satisfied, respectively. Those with video follow-up visits were 2 to 3 times (P=.01) more satisfied. Each physical therapist’s message increased weekly workouts by 11% (OR 1.11, 95% CI 1.07-1.16; P<.001). Video follow-up visits increased weekly workouts by at least 16% (OR 1.16, 95% CI 1.04-1.29; P=.01) and weeks in the program at least 8% (OR 1.08, 95% CI 1.01-1.14; P=.02). Access was associated with a 14% increase (OR 1.14, 95% CI 1.05-1.24; P=.003) in weekly workouts.

Conclusions

Similar to in-person care, program engagement positively affects clinical outcomes, and strong patient-provider relationships positively affect satisfaction. In app-based physical therapy, clinical outcomes positively affect patient satisfaction. Timely access to care and strong patient-provider relationships, particularly those forged through video visits, affect engagement.

Effect of Tai Chi Quan on the Pressure Pain Thresholds of Lower Back Muscles in Healthy Women

Purpose

Patients and Methods

Results

Conclusion

Exercise for Neuropathic Pain: A Systematic Review and Expert Consensus

Background: Neuropathic pain (NP), a severe and disruptive symptom following many diseases, normally restricts patients' physical functions and leads to anxiety and depression. As an economical and effective therapy, exercise may be helpful in NP management. However, few guidelines and reviews focused on exercise therapy for NP associated with specific diseases. The study aimed to summarize the effectiveness and efficacy of exercise for various diseases with NP supported by evidence, describe expert recommendations for NP from different causes, and inform policymakers of the guidelines.

Design: A systematic review and expert consensus.

Methods: A systematic search was conducted in PubMed. We included systematic review and meta-analysis, randomized controlled trials (RCTs), which assessed patients with NP. Studies involved exercise intervention and outcome included pain intensity at least. Physiotherapy Evidence Database and the Assessment of Multiple Systematic reviews tool were used to grade the quality assessment of the included RCTs and systematic reviews, respectively. The final grades of recommendation were based on strength of evidence and a consensus discussion of results of Delphi rounds by the Delphi consensus panel including 21 experts from the Chinese Association of Rehabilitation Medicine.

Results: Eight systematic reviews and 21 RCTs fulfilled all of the inclusion criteria and were included, which were used to create the 10 evidence-based consensus statements. The 10 expert recommendations regarding exercise for NP symptoms were relevant to the following 10 different diseases: spinal cord injury, stroke, multiple sclerosis, Parkinson's disease, cervical radiculopathy, sciatica, diabetic neuropathy, chemotherapy-induced peripheral neuropathy, HIV/AIDS, and surgery, respectively. The exercise recommended in the expert consensus involved but was not limited to muscle stretching, strengthening/resistance exercise, aerobic exercise, motor control/stabilization training and mind-body exercise (Tai Chi and yoga).

Conclusions: Based on the available evidence, exercise is helpful to alleviate NP intensity. Therefore, these expert consensuses recommend that proper exercise programs can be considered as an effective alternative treatment or complementary therapy for most patients with NP. The expert consensus provided medical staff and policymakers with applicable recommendations for the formulation of exercise prescription for NP. This consensus statement will require regular updates after five–ten years.

Top 100 Most-Cited Papers in Neuropathic Pain From 2000 to 2020: A Bibliometric Study

Background: Neuropathic pain research has grown impressively in the past two decades, as evidenced by improvements in research quality and increments in the number of research papers. In views of this situation, the use of quantitative measurements to analyze and characterize existing research has become imperative. The aim of this research is to identify and analyze the 100 most-cited papers in neuropathic pain research.

Methods: Neuropathic pain-related articles published between 2000 and 2020 were screened from Web of Science (WOS) by using the following subject terms: TI = (Neuralgia$ OR Neurodynia$ OR “Neuropathic pain” OR sciatica OR “Nerve pain$”). The publications were ranked in a descending order on the basis of citation counts, and the top 100 most-cited neuropathic pain papers were determined. Subsequently, we conducted a bibliometric study to determine the authors, journals, countries, and institutions that contributed the most to the top 100 neuropathic pain lists; describe the keywords and hotspots of the top 100 most-cited papers; and explore the factors associated with successful citations.

Results: The top 100 most-cited papers were published from 2000 to 2017, and 2003 had the largest number of published papers (n = 16). The mean number of citations per paper was 480.72, with a range of 262–1,569. Forty-four kinds of journals contributed to the top 100 most-cited papers, which were predominantly published in “Pain” (n = 23). The USA was determined to be the leader of neuropathic pain research in terms of quality and quantity.

Conclusion: This study provides a comprehensive list of the most influential papers on neuropathic pain and demonstrates the important advances in this field to help understand academic concerns and the directions of technological innovations in neuropathic pain worldwide.

Association of Chronic Low Back Pain With Personal Space Regulation

Background: While most previous studies regarding patients with chronic low back pain (CLBP) mainly focused on pain, disability, psychological damage, and intervention measures, the effect of CLBP on personal space remains unclear. The study aimed to assess the personal space of patients with CLBP and healthy controls, explored the differences between the two groups, and examined whether pain, dysfunction, anxiety, and depression affected the personal space regulation. Methods: The cross-sectional study recruited 24 patients with CLBP and 24 healthy controls at Shanghai Shangti Orthopedic Hospital and Shanghai University of Sport, Shanghai, China, from December 2018 to January 2019. A stop-distance paradigm was applied to measure the comfortable and uncomfortable distance under four conditions. A self-rating anxiety scale (SAS) and a self-rating depression scale (SDS) were used to examine the anxiety and depression levels of all participants. The pain intensity and dysfunction in the CLBP group were evaluated by the numeric rating scale and Roland-Morris questionnaire (RMDQ), respectively. Results: When approaching another individual or when being approached, the interpersonal distance under all the conditions in the CLBP group significantly differed from that in the healthy control group with larger space distances (p < 0.01). Gender had a significant main effect on the regulation of personal space in patients with CLBP (p < 0.05). The average pain intensity, scores on RMDQ, SAS, and SDS had a significant positive correlation with the interpersonal distance under the Same or Opposite Gender condition (p < 0.05). Conclusion: People with CLBP show an atypical personal space behavior and indeed have a greater interpersonal distance to strangers. The higher the pain intensity, dysfunction, anxiety, and depression, the greater the interpersonal distance in patients with CLBP. In the future, the effect and underlying neural mechanisms of pain and negative emotions on social withdrawal in patients should be examined.