A Role for Superficial Heat Therapy in the Management of Non-Specific, Mild-to-Moderate Low Back Pain in Current Clinical Practice: A Narrative Review

Heat Therapy for Musculoskeletal Pain Conditions: Actionable Suggestions for Pharmacists from a Panel of Experts

Musculoskeletal disorders represent one of the most pervasive health concerns that drive frequent medical consultations and pharmacy encounters. Community pharmacies are well placed to help address this demand as they are accessible settings for healthcare advice and support for patients with musculoskeletal disorders complaining of pain. Heat therapy stands as a valuable component of a multimodal approach to the management of musculoskeletal pain by virtue of multiple effects: pain relief, reduction of muscle spasms and stiffness, and enhanced muscle flexibility and range of motion. However, there is limited guidance on heat therapy use in routine practice, particularly on indications and contraindications, mode of application, and precautions. Such an educational gap has been documented among pharmacists. Therefore, it is paramount that pharmacists gain knowledge about when and how to effectively integrate superficial heat therapy with both pharmacological and physical therapy, to provide patients with a comprehensive, multimodal approach to alleviating musculoskeletal pain. A multidisciplinary panel of experts gathered to develop practical guidance on heat therapy-appropriate application in patients with musculoskeletal pain. In this work, we provide actionable suggestions to build pharmacists' competency in managing musculoskeletal pain and empower them in effectively using heat therapy as a single therapeutic option or in combination with over-the-counter analgesics.

The Effects of Joint Mobilization and Myofascial Release on Muscle Thickness in Non-Specific Low Back Pain: A Randomized Clinical Trial

Background: Non-specific low back pain is a discomfort that affects individuals at any point in their lives. This study's aim was to determine the effects of myofascial release and joint mobilization on muscle thickness via ultrasonography in individuals experiencing non-specific low back pain. Methods: This double-blinded randomized clinical trial was conducted on 84 participants in three groups: joint mobilization, myofascial release, and a combination of joint mobilization and myofascial release. Data were collected during a two-week treatment regimen (days 1, 4, 8, and 12) and at a one-month follow-up. Ultrasound evaluations were used to measure the thickness of deep lumbar muscles at rest and contraction, i.e., the transverse abdominis (rTrA and cTrA) and lumbar multifidus (rLM and cLM). Repeated-measures ANOVA was utilized to analyze the follow-ups within the groups and among the groups, with post hoc tests conducted to identify specific differences. Results: Significant increases in muscle thickness were observed over time in the transverse abdominis, with improvements in both rTrA (right, p = 0.001; left, p = 0.001) and cTrA (right, p = 0.001; left, p = 0.008). The lumbar multifidus also demonstrated significant changes, with increases in the rLM (right, p = 0.001; left, p = 0.047) and cLM (right, p = 0.004; left, p = 0.037). However, the main effects showed no significant differences in muscle thickness among the groups. Conclusions: Joint mobilization demonstrated increased effectiveness in improving muscle thickness relative to myofascial release and a combination of both treatments for individuals with non-specific low back pain.

Short-term effects of exergaming on patients with chronic low back pain: A single-blind randomized controlled trial

BACKGROUND

Exergaming is increasingly popular, but its impact on chronic low back pain (CLBP) remain unclear.

OBJECTIVES

To evaluate the effectiveness of exergaming versus traditional exercise for managing CLBP using the International Classification of Functioning, Disability and Health (ICF) framework.

METHODS

This single-blind, randomized controlled trial included 70 participants with CLBP, who were assigned to either the exergaming or traditional exercise group. Both groups received 2 weeks of treatment with six sessions. Assessments included the Oswestry Disability Index (ODI), range of motion, Hospital Anxiety and Depression Scale (HADS), balance (Biodex Stability System), Fear-Avoidance Beliefs Questionnaire (FABQ), and physical performance tests.

RESULTS

After six sessions over 2 weeks, the exergaming group showed significant improvements over the exercise group in ODI (p < 0.001), chair-rising time (p = 0.001), stair ascent (p = 0.025) and descent times (p < 0.001), flexion (p = 0.005), extension (p = 0.001), balance (p = 0.012), and FABQ subscales (physical activity: p = 0.003; work: p < 0.001) at the 3-month follow-up. Group × time interaction effects favored exergaming for ODI (p = 0.012), chair-rising (p = 0.045), stair ascent (p = 0.010), and descent (p = 0.002) times. While these changes did not meet clinical significance, exergaming was not inferior to traditional exercise in improving spinal motion, physical performance, fear-avoidance beliefs, and disability.

CONCLUSION

Exergaming appears to be a viable supplementary therapy for patients with CLBP, offering benefits across all ICF domains. Future studies with longer intervention durations are needed to assess its long-term effects.

Complementary Approaches to Postoperative Pain Management: A Review of Non-pharmacological Interventions

Postoperative pain significantly affects many surgical patients. While opioids are crucial for pain management, they come with unwanted side effects. Alternatives like nonsteroidal anti-inflammatory drugs, N-methyl-D-aspartate (NMDA) receptor antagonists, and regional anesthesia techniques such as nerve blocks are utilized, but these also have limitations. This underscores the need for complementary non-pharmacological interventions to enhance postoperative pain control and reduce opioid dependence. This study aimed to synthesize evidence on the efficacy of nondrug approaches for managing postoperative pain. The study examined the effects of non-pharmacological interventions such as preoperative patient education, mind-body modalities, and physical therapies. Findings suggest that these approaches can reduce pain intensity, decrease opioid consumption, and enhance recovery outcomes. The study also highlighted the pivotal role of healthcare professionals in implementing these strategies. However, it identified workload constraints and insufficient training as barriers to effective utilization in clinical practice. Integrating non-pharmacological interventions into multimodal pain management regimens can improve postoperative pain control and reduce reliance on opioids. Further research is crucial to definitively establish the efficacy of individual interventions and optimize their combined use in clinical practice. Additionally, enhanced training programs for nurses and initiatives to facilitate the implementation of these strategies are necessary for their successful adoption.

Quality appraisal of systematic reviews on high-intensity laser therapy for musculoskeletal pain management: an umbrella review

Musculoskeletal pain (MSP) remains one of the leading causes of disability worldwide. Recent approaches to treating this condition have prompted the development of several systematic reviews investigating the efficacy of high-intensity laser therapy (HILT), whose analgesic mechanisms are based on photobiomodulation neural inhibition, endorphin and serotonin release and anti-inflammatory effects. To assess the methodological quality, reliability, and validity of the systematic reviews (SRs) on HILT in MSP. This study is an overview of SRs (umbrella review) with an observational, retrospective, and secondary design. The search considered PubMed, Scopus, Web of Science, CINAHL, Embase, Cochrane Library, ScienceDirect, and Google Scholar databases (updated October 23, 2024). The primary focus was on the methodological quality of the reviews and their reporting of pain intensity results. The HILT effects on pain intensity were reported using mean differences (MD) or standardized mean differences (SMD). The quality assessment was conducted using the A Measurement Instrument to Assess Systematic Reviews 2 checklist (AMSTAR-2), and the findings were synthesized narratively. The MD and SMD obtained from all reviews were presented using forest plots. The Shapiro-Wilk normality test assessed MD and SMD distributions for pain intensity across meta-analyses. The average MD and SMD, along with their respective confidence intervals (CI), were estimated and presented based on the aggregate study outcomes. Twenty SRs were included, fourteen of which conducted meta-analyses covering diverse musculoskeletal disorders such as knee osteoarthritis, epicondylalgia, myofascial pain, frozen shoulder, plantar fasciitis, neck, and low back pain. The primary databases used were PubMed, Web of Science, and the Cochrane Library. The AMSTAR-2 average score was 12.9 points (± 1.8), indicating varying methodological quality with one or two criteria resulting in low or critically low. HILT's best analgesic effects are observed in frozen shoulder disorder (MD = -2.23 cm; 95% CI:-3.3,-1.2; p < 0.01), knee osteoarthritis (MD = -1.9 cm; 95% CI:-2.0,-1.8;p < 0.01), low back pain (MD = -1.9 cm; 95% CI = -2.9,-1.0; p < 0.01), and myofascial pain (MD = -1.9 cm; 95% CI:-2.6,-1.2; p < 0.01). Largest effect sizes are for neck pain (SMD = 2.1; 95% CI = 1.2,3.0, p < 0.05) and low back pain (SMD = 1.1 (95% CI = 1.4,0.8; p < 0.01). This review underscores the generally low to critically low methodological quality of SRs on HILT, as assessed by AMSTAR-2. Key areas for improvement for future SRs of RCTs include addressing publication bias, disclosing funding sources, and enhancing search strategies and discussions on heterogeneity. The scarcity of RCTs for conditions such as temporomandibular disorders, carpal tunnel syndrome, and myofascial pain highlights the need for further research. SRs on spinal disorders, frozen shoulder, and neck pain demonstrated the most favorable analgesic effects, providing valuable insights for clinical practice and future RCTs.

The Effect of Superficial Heat-Cold Application on the Sleep Quality of Patients With Restless Leg Syndrome: A Systematic Review and Meta-Analysis

AIM

The present study was conducted to determine the effect of the superficial heat-cold application on the sleep quality of patients with restless leg syndrome.

DESIGN

This study was a systematic review and meta-analysis.

METHODS

In the present study, the electronic databases Scopus, ProQuest, Web of Science, PubMed, SID and Google Scholar were searched from their inception to September 2023. The quality of included studies was evaluated through the Cochrane Collaboration's Risk of Bias Tool, and finally, a meta-analysis was conducted by calculating standardised mean differences (SMDs).

RESULTS

The meta-analysis results revealed that superficial heat-cold application improved sleep quality in patients with RLS (SMD = 0.685, 95% CI: 0.421-0.950). The meta-regression results showed that as the temperature increased, the intervention was more effective in improving sleep quality (β = 0.0182, 95% CI: 0.0096-0.0268, p < 0.05). Moreover, the effectiveness of the intervention in improving the sleep quality of patients with RLS reduced significantly as the duration of intervention in each session (β = -0.031, 95% CI: -0.059 to -0.001, p < 0.05) as well as participants' age increased (β = -0.013, 95% CI: -0.024 to -0.001, p = 0.0259).

PATIENT OR PUBLIC CONTRIBUTION

This research showed that superficial heat-cold application had the capability to improve the sleep quality of patients with restless leg syndrome. In addition, in this study, settings were suggested according to which the maximum effectiveness of the intervention could be achieved.

Expert opinion on heat therapy for teenagers' musculoskeletal pain management

Background

Among children and adolescents, up to 40% will experience musculoskeletal pain (MP), which can significantly impair functional ability, reduce quality of life, cause emotional distress, and lead to sleeping disorders for both patients and their families. The first-line treatment often involves pharmacological interventions, even though there is a lack of evidence supporting the efficacy or the safety of this approach in this specific age group. Recent guidelines recommend the implementation of preventative strategies and physical tools as the first option to minimize the use of medications. We aimed to provide an expert opinion on the use of heat therapy for MP management in young patients.

Methods

This paper is the result of a virtual advisory board held by the authors in order to discuss and provide an expert opinion about the use of heat therapy in MP in children and adolescents.

Results

MP is a significant burden affecting children and adolescents. While non-steroidal anti-inflammatory drugs are currently the first-choice treatment of acute and chronic MP in children and adolescents, avoiding or reducing them in such patients is advisable, to reduce side effects and to prevent the development of chronic pain and medication overuse headaches. Heat therapy can be an additional treatment option due to its ability to promote muscle relaxation, enhance blood circulation, and modulate nociceptors with a good safety profile.

Conclusions

MP in children and adolescents is a common condition that should be approached multidisciplinary, including information, therapeutic exercise and physical therapies like hot or cold therapies. Future studies should be conducted to evaluate the safety, efficacy and indications of each treatment in MP.

A Local Heating Profile to Manage Lower Back Pain in an Automotive Seat: A Pilot Study

Lower back pain (LBP) is one of the most prevalent health losses in adults worldwide. Historically, heat has been successfully used for treating pain and relieving tight muscles. Given the effective contact with the occupant's back and proximity to the heat source, coupled with increasing commute times, automotive seats offer an opportunity to intervene. Fifteen adults (nine female) who experienced acute, subacute, and chronic lower back pain were recruited to examine the effectiveness of heat delivered to the lower back in providing temporary pain relief. Participants sat in a car seat for 38 min on two days, which included a 5-min baseline followed by a 33-min intervention; control, or localized. For the control condition, participants sat for 33 min without any thermal devices on, while the localized condition heated and maintained the seat surface temperature of the lower seat back area to ~45 °C. Over the 33-min control condition, the back skin temperature increased by ~1-2 °C and did not impact the subjective LBP. Heating the lower back for 33 min to ~39 °C reduced the subjective LBP by 10%. We demonstrated that lower back pain can be alleviated from an automotive seat providing heat to the lower back within normal commute times in those with lower back pain.

Efficacy of High-intensity laser therapy in patients with temporomandibular joint disorders: A systematic review and meta-analysis

This study aimed to assess the effects of High-intensity laser therapy (HILT) on individuals suffering from temporomandibular joint disorders (TMDs). A search was conducted across six electronic databases for randomized controlled trials (RCTs) focusing on HILT for TMDs: PubMed, Scopus, Web of Science, ScienceDirect, EBSCOhost, Cochrane Library, the PEDro database and Google Scholar (last updated on July 18, 2024). Eligible studies were chosen by independent reviewers, and their quality was assessed with the Cochrane risk of bias tool (RoB). The main outcome was pain intensity (VAS), with secondary outcomes including mouth opening (mm), disability (JFLS-20), and quality of life (OHIP-14). A meta-analysis was conducted to assess the pooled effect by calculating mean differences (MD) for these variables (95% confidence level). The heterogeneity of the meta-analyses was explored using the I2 statistic. Three studies met the selection criteria and were included in the meta-analysis. The main RoB was the blinding of participant and treaters. Statistically significant differences (p < 0.05) in favor of HILT were observed for VAS and maximum mouth opening. The pooled effect showed an MD of -14.8 mm (95% CI:-27.1,-2.5) for pain intensity and 3.7 mm (95% CI:0.9,6.5) for mouth opening, changes that were assessed as clinically important. According to GRADE, the evidence was rated as important, and the certainty was moderate due to the heterogeneity between studies. A sensitivity analysis was not performed to address heterogeneity, primarily due to the limited availability of RCTs. HILT has been found effective in short-term pain relief and improvement of jaw opening in TMDs, potentially enhancing quality of life by facilitating activities such as chewing, jaw mobility, and communication. However, further research is needed to confirm its long-term effectiveness. Combining HILT with interventions such as occlusal splints or therapeutic exercises could potentially enhance its effects, leveraging the existing evidence supporting these treatments. It is important to note that the high RoB associated with the lack of blinding of participants and treaters may influence data collection, compromising the internal validity of findings in some studies.

Effectiveness of Dry Heat Versus Moist Heat Modalities on Pain Intensity and Wound Healing of Episiotomies Among Postnatal Women: A Systematic Review and Meta-Analysis

OBJECTIVES

Comparison of the effects of dry heat versus moist heat therapy modalities on the intensity of pain and wound healing of episiotomies among postnatal women.

DESIGN

A Systematic review and meta-analysis of controlled trials.

DATA SOURCES

Six databases searched for original articles using relevant keywords until September 10, 2023, without time or language restrictions.

REVIEW/ANALYSIS METHODS

All analyses employed Comprehensive Meta-Analysis (CMA) V.2. The measure of heterogeneity was computed using Cochran's Q-value. The I2 index was employed to quantitatively demonstrate heterogeneity. Statistical significance was reported for P-values <0.05 and I2>50%.

RESULTS

Four quasi-experimental and three randomized controlled trials (RCTs) studies with moderate-to-good quality evidence met inclusion criteria. On the third to fifth day after the intervention in the dry heat group, the amount of pain was significantly lower than in the group that used moist heat [MD (95% CI) =-1.395 (-2.374, -0.416), P=0.005]. The use of a hair dryer significantly reduced pain (P=0.029), but an infrared lamp did not significantly reduce pain compared to moist heat (P=0.064). As compared to the moist heat group, the women using dry heat experienced better wound healing to the extent of 2.002 units of the REEDA (Redness, Edema, Ecchymosis, Discharge, Approximation) scale, which was statistically significant [MD (95% CI) = -2.002 (-2.785, -1.219), P<0.001].

CONCLUSION

Compared to sitz baths, dry heat reduced pain and improved episiotomy site healing in postnatal women. Therefore, dry heat, especially hair dryers, is suggested as a non-pharmacological strategy inside maternity hospitals, but additional targeted, high-quality trials are needed.

Heat therapy for different knee diseases: expert opinion

Musculoskeletal pain is a major burden in our society. Management of musculoskeletal pain or injuries includes both pharmacological and non-pharmacological approaches, including heat therapy (HT). HT is a well-established treatment option due to its ability to promote muscle relaxation, enhance blood circulation, and modulate nociceptors with a good safety profile. The main focus of this paper is to review the available literature about HT in knee pathologies (i.e., arthrosis, arthritis, traumatic pathologies in the subacute phase, muscle and tendon pathologies linked to fatigue, muscle tension and distractions) and to provide an expert opinion in case of lack of data.

BackMov: Individualized Motion Capture-Based Test to Assess Low Back Pain Mobility Recovery after Treatment

Low back pain (LBP) is a common issue that negatively affects a person's quality of life and imposes substantial healthcare expenses. In this study, we introduce the (Back-pain Movement) BackMov test, using inertial motion capture (MoCap) to assess lumbar movement changes in LBP patients. The test includes flexion-extension, rotation, and lateralization movements focused on the lumbar spine. To validate its reproducibility, we conducted a test-retest involving 37 healthy volunteers, yielding results to build a minimal detectable change (MDC) graph map that would allow us to see if changes in certain variables of LBP patients are significant in relation to their recovery. Subsequently, we evaluated its applicability by having 30 LBP patients perform the movement's test before and after treatment (15 received deep oscillation therapy; 15 underwent conventional therapy) and compared the outcomes with a specialist's evaluations. The test-retest results demonstrated high reproducibility, especially in variables such as range of motion, flexion and extension ranges, as well as velocities of lumbar movements, which stand as the more important variables that are correlated with LBP disability, thus changes in them may be important for patient recovery. Among the 30 patients, the specialist's evaluations were confirmed using a low-back-specific Short Form (SF)-36 Physical Functioning scale, and agreement was observed, in which all patients improved their well-being after both treatments. The results from the specialist analysis coincided with changes exceeding MDC values in the expected variables. In conclusion, the BackMov test offers sensitive variables for tracking mobility recovery from LBP, enabling objective assessments of improvement. This test has the potential to enhance decision-making and personalized patient monitoring in LBP management.

Multimodal Approach to Pain Management in Veterinary Rehabilitation

Pain recognition, assessment, and management is a primary focus and an integral part of veterinary rehabilitation. Evidence-based pain mitigation protocols will use both pharmacologic tools and nonpharmacologic methods to create a customized, safe, and effective treatment plan. A multimodal, patient-centered approach will allow for the best outcomes for pain relief and improved quality of life.

White matter microstructure predicts measures of clinical symptoms in chronic back pain patients

Chronic back pain (CBP) has extensive clinical and social implications for its sufferers and is a major source of disability. Chronic pain has previously been shown to have central neural factors underpinning it, including the loss of white matter (WM), however traditional methods of analyzing WM microstructure have produced mixed and unclear results. To better understand these factors, we assessed the WM microstructure of 50 patients and 40 healthy controls (HC) using diffusion-weighted imaging. The data were analyzed using fixel-based analysis (FBA), a higher-order diffusion modelling technique applied to CBP for the first time here. Subjects also answered questionnaires relating to pain, disability, catastrophizing, and mood disorders, to establish the relationship between fixelwise metrics and clinical symptoms. FBA determined that, compared to HC, CBP patients had: 1) lower fibre density (FD) in several tracts, specifically the right anterior and bilateral superior thalamic radiations, right spinothalamic tract, right middle cerebellar peduncle, and the body and splenium of corpus callosum; 2) higher FD in the genu of corpus callosum; and 3) lower FDC - a combined fibre density and cross-section measure - in the bilateral spinothalamic tracts and right anterior thalamic radiation. Exploratory correlations showed strong negative relationships between fixelwise metrics and clinical questionnaire scores, especially pain catastrophizing. These results have important implications for the intake and processing of sensory data in CBP that warrant further investigation.

Musculoskeletal Pain Management and Thermotherapy: An Exploratory Analysis of Italian Physicians' Attitude, Beliefs, and Prescribing Habits

Purpose

In Italy, musculoskeletal (MSK) disorders are pervasive with one-third of adults seeking medical consultation for a MSK issue in the past year. MSK pain is often treated with local heat applications (LHAs) which can be integrated into MSK care by different specialists and in different settings. Compared to analgesia and physical exercise, LHAs have been less evaluated, and the quality of randomized clinical trials is generally low. The aim of the survey is to assess the knowledge, attitude, perception/practices of general practitioners (GPs), physiatrists and sports medicine doctors towards thermotherapy as delivered by superficial heat pads or wraps.

Patients and Methods

The survey was conducted between June and September 2022 in Italy. An online questionnaire with 22 multiple-choice questions was administered to explore the demographics and prescribing habits of the participants; the clinical profile of MSK patients; and physicians' attitude and beliefs about the use of thermotherapy/superficial heat applications in MSK pain management.

Results

GPs are at the forefront of the MSK patient journey and preferentially select NSAIDs as first-line option in arthrosis, muscle stiffness, and strain while prescribing heat wraps as preferred choice in presence of muscle spasm/contracture. Similar pattern of prescribing habits was found among specialists who, in contrast to GPs, adopted more frequently ice/cold therapy to relieve pain due to muscle strain and limited paracetamol use. Generally, survey participants agreed on the benefits of thermotherapy in MSK care management, namely increased blood flow and local tissue metabolism as well as connective tissue elasticity and pain relief which all may be of help in attaining pain control and improvement of function.

Conclusion

Our findings provided the basis for further investigations aimed at optimizing the MSK patient journey while building up additional evidence supporting the benefit of using superficial heat applications to effectively manage patients with MSK disorders.

Silver Nanoparticle-Decorated Multiwalled Carbon Nanotube Ink for Advanced Wearable Devices

Silver nanoparticles of average size 12-13 nm were successfully decorated on the surface of multiwalled carbon nanotubes (MWCNTs) through a scalable wet chemical method without altering the structure of the MWCNTs. Employing this Ag@MWCNT, a multifunctional room-temperature curable conductive ink was developed, with PEDOT:PSS as the conductive binder. Screen printing of the ink could yield conductive planar traces with a 9.5 μm thickness and a conductivity of 28.99 S/cm, minimal surface roughness, and good adhesion on Mylar and Kapton. The versatility of the ink for developing functional elements for printed electronics was demonstrated by fabricating prototypes of a wearable strain sensor, a smart glove, a wearable heater, and a wearable breath sensor. The printed strain sensor exhibited a massive sensing range for wearable applications, including an impressive 1332% normalized resistance change under a maximum stretchability of 23% with superior cyclic stability up to 10 000 cycles. The sensor also exhibited an impeccable gauge factor of 142 for a 5% strain (59 for 23%). Furthermore, the sensor was integrated into a smart glove that could flawlessly replicate a human finger's gestures with a minimal response time of 225-370 ms. Piezoresistive vibration sensors were also fabricated by printing the ink on Mylar, which was employed to fabricate a smart mask and a smart wearable patch to monitor variations in human respiratory and pulmonary cycles. Finally, an energy-efficient flexible heater was fabricated using the developed ink. The heater could generate a uniform temperature distribution of 130 °C at the expense of only 393 mW/cm² and require a minimum response time of 20 s. Thus, the unique formulation of Ag@MWCNT ink proved suitable for versatile devices for future wearable applications.

Feasibility study of a LED light irradiation device for the treatment of chronic neck with shoulder muscle pain/stiffness

Neck with shoulder muscle stiffness/pain is a common disorder. Commonly used physical therapy, pharmacotherapy, acupuncture, and moxibustion only temporarily alleviate the disorder in most cases, thus the disorder often recurs. Low power laser therapy is often used for neck and shoulder stiffness/pain and has been effective in clinical trials. In this study, we evaluated the safety and effectiveness of a newly developed self-care device for disorders including neck with shoulder muscle stiffness/pain. The device incorporates light-emitting diodes (LEDs), which are safer than lasers, as its light source. Ten adults with neck with shoulder muscle stiffness/pain were subject to LED irradiation (wavelength 780 nm ± 15 nm, output 750 mW, power density 3.8 W/cm2, energy density 5.7×102 J/cm2) for 3 minutes on the affected shoulder at a standard acupuncture point (GB21, Jianjing). Immediately after irradiation, the subjective symptoms of the neck with shoulder muscle stiffness and pain evaluated by a visual analog scale were improved from 58.3 mm ± 18.7 mm to 45.5 mm ± 21.5 mm and from 45.8 mm ± 23.3 mm to 39.4 mm ± 21.8 mm, respectively. The symptoms further improved after 15 minutes of irradiation. The skin temperature at the irradiated point increased from 34.3°C ± 1.1°C to 41.0°C ± 0.7°C. The increase in skin temperature was observed within approximately 5 cm of the irradiated area. There was no effect on the heart rate variability, a measure of the autonomic nervous system; however, the baroreflex sensitivity was slightly increased. No irradiation-related adverse skin events were observed. Our LED irradiation device was found to be safe, and it improved the subjective symptoms of muscle stiff neck with shoulders.

Transient Receptor Potential (TRP) and Thermoregulation in Animals: Structural Biology and Neurophysiological Aspects

This review presents and analyzes recent scientific findings on the structure, physiology, and neurotransmission mechanisms of transient receptor potential (TRP) and their function in the thermoregulation of mammals. The aim is to better understand the functionality of these receptors and their role in maintaining the temperature of animals, or those susceptible to thermal stress. The majority of peripheral receptors are TRP cation channels formed from transmembrane proteins that function as transductors through changes in the membrane potential. TRP are classified into seven families and two groups. The data gathered for this review include controversial aspects because we do not fully know the mechanisms that operate the opening and closing of the TRP gates. Deductions, however, suggest the intervention of mechanisms related to G protein-coupled receptors, dephosphorylation, and ligands. Several questions emerge from the review as well. For example, the future uses of these data for controlling thermoregulatory disorders and the invitation to researchers to conduct more extensive studies to broaden our understanding of these mechanisms and achieve substantial advances in controlling fever, hyperthermia, and hypothermia.