Search Results (128)

Background: Regulating sensations of fatigue and discomfort while performing maximal endurance exercise becomes essential for making informed decisions about persistence and/or failure during intense exercise. Athletes with a higher effort capacity have competitive advantages over those with a lower one. The microbiota–brain axis is a considered the sixth sense and a modulator of the host’s emotional stability and physical well-being. Objectives: This narrative review aims to explore and evaluate the potential mechanisms involved in regulating perceptions during endurance exercise, with a focus on the possible relationship between the gut microbiota balance and the neural system as an adaptive response to high fatigue chronic exposure. Methods: Electronic databases (PubMed, Web of Science, Google Scholar, and Scopus) were used to identify studies and hypotheses that had documented predefined search terms related to endurance exercise, gut microbiota, the central nervous system, pain, discomfort, fatigue, and tolerance to effort. Results: This narrative review shifts the focus concerning the symbiotic relationship between the gut microbiota, the vagus nerve, the central/enteric nervous system, and the regulation of afferences from different organs and systems to manage discomfort and fatigue perceptions during maximal physical effort. Consequently, the chronicity supporting fatigued exercise and nutritional stimuli could specifically adapt the microbiota–brain connection through chronic efferences and afferences. The present hypothesis could represent a new focus to be considered, analysing individual differences in tolerating fatigue and discomfort in athletes supporting conditions of intense endurance exercise. Conclusions: A growing body of evidence suggests that the gut microbiota has rapid adaptations to afferences from the brain axis, with a possible relationship to the management of fatigue, pain, and discomfort. Therefore, the host–microbiota relationship could determine predisposition to endurance performance by increasing thresholds of sensitive afferences perceived and tolerated. A richer and more diverse GM of athletes in comparison with sedentary subjects can improve the bacteria-producing metabolites connected to brain activity related with fatigue. The increase in fatigue thresholds directly improves exercise performance, and the gut–brain axis may contribute through the equilibrium of metabolites produced for the microbiota. Full article

Background: Chronic musculoskeletal pain (CMP) is a multidimensional condition involving both peripheral and central mechanisms, with increasing evidence supporting an interplay between subjective pain perception and autonomic nervous system (ANS) function. However, few studies have explored whether a single non-invasive intervention can concurrently modulate both domains. Objectives: To evaluate the short-term effects of a single session of Pulsed Electromagnetic Field (PEMF) therapy—administered via the PAP Ion Magnetic Induction (PAPIMI™) device—on subjective pain intensity and heart rate variability (HRV) parameters in individuals with CMP. The relationship between perceived pain relief and physiological autonomic adaptations was also explored. Methods: Thirty adults with CMP underwent a single PAPIMI™ session. Subjective pain intensity was measured using the Numeric Pain Rating Scale (NPRS), while autonomic function was assessed via HRV. Pre- to post-intervention changes were analyzed using the Wilcoxon Signed-Rank test, while Spearman’s correlation was computed to assess associations between post-intervention changes in subjective perceived pain and HRV parameters. Results: A significant reduction in NPRS scores (p < 0.001) was found after PAPIMI intervention. Also, a significant increase in specific parasympathetic-related HRV indices, namely, RMSSD (p = 0.015) and HF power (p = 0.029), was observed. No significant correlations were found between post-intervention changes in pain perception and HRV metrics. Conclusions: A single PAPIMI session induced both analgesic effects and improvements in autonomic balance in individuals with CMP. These findings underscore the potential of PAPIMI as a non-pharmacological approach for rapid pain modulation and systemic rebalancing. Full article

The objective of this study was to analyze the impact of solar and hybrid dryers on the physicochemical characteristics, fingerprints, and cognitive-sensory perceptions of Mexican consumers of traditional tostadas made with corn of different races. Corn tostadas from different native races were evaluated with solar and hybrid (solar-photovoltaic solar panels) dehydration methods. Proximal chemical quantification, instrumental analysis (color, texture), fingerprint by Fourier transform infrared spectroscopy (FTIR), and sensory-cognitive profile (emotions and memories) and its relationship with the level of pleasure were carried out. The data were evaluated using analysis of variance models, Cochran Q, and an external preference map (PREFMAP). The results showed that the drying method and corn race significantly (p < 0.05) affected only moisture content, lipids, carbohydrates, and water activity. Instrumental color was influenced by the corn race effect, and the dehydration type influenced the fracturability effect. FTIR fingerprinting results revealed that hybrid samples exhibited higher intensities, particularly associated with higher lime concentrations, indicating a greater exposure of glycosidic or protein structures. Race and dehydration type effects impacted the intensity of sensory attributes, emotions, and memories. PREFMAP vector model results revealed that consumers preferred tostadas from the Solar-Chiquito, Hybrid-Pepitilla, Hybrid-Cónico, and Hybrid-Chiquito races for their higher protein content, moisture, high fracturability, crunchiness, porousness, sweetness, doughy flavor, corn flavor, and burnt flavor, while images of these tostadas evoked positive emotions (tame, adventurous, free). In contrast, the Solar-Pepitilla tostada had a lower preference because it was perceived as sour and lime-flavored, and its tostada images evoked more negative emotions and memories (worried, accident, hurt, pain, wild) and fewer positive cognitive aspects (joyful, warm, rainy weather, summer, and interested). However, the tostadas of the Solar-Cónico race were the ones that were most rejected due to their high hardness and yellow to blue tones and for evoking negative emotions (nostalgic and bored). Full article

We explore the feasibility of classifying perceived pain intensity—despite the stimulus being identical—using multimodal physiological signals and self-reported emotional ratings. A total of 112 healthy participants watched the same anger-inducing video, yet reported varying pain intensities (5, 6, or 7 on a 7-point scale). We recorded electrocardiogram, skin conductance (SC), respiration, photoplethysmogram results, and finger temperature, extracting 12 physiological features. Participants also rated their valence and arousal. Using a random forest model, we classified pain versus baseline and distinguished intensity levels. Compared to baseline, the painful stimulus altered heart rate variability, SC, respiration, and pulse transit time (PTT). Higher perceived pain correlated with more negative valence, higher arousal, and elevated SC, suggesting stronger sympathetic activation. The classification of baseline versus pain using SC and respiratory features reached an F1 score of 0.83. For intensity levels 6 versus 7, including PTT and skin conductance response along with valence achieved an F1 score of 0.73. These findings highlight distinct psychophysiological patterns that reflect perceived intensity under the same stimulus. SC features emerged as key biomarkers, while valence and arousal offered complementary insights, supporting the development of personalized, psychologically informed pain assessment systems. Full article

Background and Objectives: Osteoarthritis (OA) of the knee and hip is a major cause of pain and functional impairment. This study evaluated the effects of non-immersive virtual reality (NIVR) combined with conventional physical therapy (CPT) on pain intensity, mechanical hyperalgesia, and perceived recovery in older adults with OA. Materials and Methods: Sixty older adults with mild-to-moderate knee or hip OA were randomly assigned to a NIVR group (NIVR-G; n = 30) or a CPT group (CPT-G; n = 30). Both groups completed 30 sessions over 10 weeks (3 sessions/week). The NIVR-G performed 20 minutes of exergames integrated into CPT. Pain intensity was assessed using the Visual Analog Scale (VAS), and mechanical hyperalgesia was evaluated through pressure pain thresholds (PPTs). Secondary outcomes included the Global Rating of Change (GRoC) and the minimal clinically important difference (MCID) for the VAS. This study is a secondary analysis of a randomized controlled trial registered at ClinicalTrials.gov (ID: NCT05839262). Results: The NIVR-G demonstrated significant reductions in pain intensity after 30 sessions (p < 0.05, d = 1.50), with greater improvements compared to the CPT-G (p < 0.05, d = 1.17). The MCID for the VAS was established at 9.2 mm, with a higher proportion of responders in the NIVR-G (p < 0.05). The NIVR-G also reported superior recovery perception on the GRoC scale (p < 0.05). No significant changes in PPTs were observed in either group. However, the improvements in the NIVR-G diminished four weeks post-intervention. Conclusions: NIVR exergames combined with CPT significantly reduced pain intensity, improved perceived recovery, and resulted in a higher proportion of responders compared to CPT alone. These findings support the use of NIVR as an effective adjunct to CPT in older adults with OA; however, further research is needed to optimize its long-term benefits. Full article

Background/Objectives: In 2022, 2.2 million adolescents were diagnosed with substance use disorders, including 265,000 with opioid use disorder. The National Survey on Drug Use and Health revealed that 130,000 adolescents misused prescription pain medications, often obtaining them from friends or relatives. This age group perceives weekly heroin use as less risky than those younger or older. Methods: A questionnaire was developed for 7th to 12th graders in a rural Texas school district as part of a fentanyl awareness curriculum. The questionnaire included Likert scale, multiple choice, and yes/no questions. The participants were categorized into younger (grades 7th and 8th) and older students (grades 9th through 12th), and associations were explored between demographic characteristics, responses, and grade groups using chi-square tests. To assess confidence, behavior, and the impact of education, we used chi-square and Fisher’s exact tests. Results: The participants (n = 94; 85.11%) identified as Hispanic or Latino, with a smaller percentage identifying as White or more than one race. An association was found between feeling more in control of actions related to substances and fentanyl (p-value = 0.04) after receiving education. No association was found between education and confidence in identifying fentanyl. Conclusions: This study aligns with a surge in fentanyl-related overdose deaths in a high-intensity drug trafficking region. Recent fentanyl overdoses among school-age children prompted legislative changes in 2023, making this study valuable for understanding the epidemic within the geographical context. These results suggest that school-based education may play a role in strengthening adolescents’ behavioral intentions to fentanyl exposure, though additional efforts are needed to improve risk identification. Full article

Background/Objectives: Venipuncture is a painful and distress-inducing procedure, especially in adolescents. However, the effect of stress on venipuncture pain remains unclear. This study investigated the relationships between stress (venipuncture-related and general stress) and venipuncture pain intensity and unpleasantness, hypothesizing that higher stress levels would be associated with greater pain levels. Methods: Forty-two adolescents (five boys, mean age 12.2 ± 1.4) participated in the study, which included completing questionnaires and a blood draw. General stress was assessed using the Perceived Stress Scale. Before the blood draw, participants were asked to rate their venipuncture-related stress level using a Visual Analog Scale (VAS). Following venipuncture, participants rated their pain intensity and pain unpleasantness using the VAS. Nineteen participants returned for a similar study visit after 1 year. Regression models were used to assess the relationships between pain and stress. In addition, correlations were used to examine the relationships between baseline and 1-year follow-up stress and pain levels. Results: Only baseline venipuncture stress, but not general stress, was related to venipuncture pain intensity (estimate (SE) = 0.185 (0.046), t-ratio = 4.00, p < 0.001) and pain unpleasantness (estimate (SE) = 0.378 (0.116), t-ratio = 3.27, p = 0.002). Baseline stress levels were related to stress levels at 1-year follow-up. However, this was not found for pain levels. In addition, stress at baseline did not impact pain levels at 1-year follow-up. Conclusions: General stress may be different from venipuncture stress, with the latter having a greater influence on venipuncture pain. Developing interventions focused on reducing stress related to venipuncture in adolescents could assist in reducing pain and increase willingness to undergo needle procedures. Full article

Background and Objectives: The objective of our study was to describe the biopsychosocial profile of individuals diagnosed with axial spondyloarthritis (AxSpA) and to analyze how their clinical characteristics interact with disease activity. Materials and Methods: An observational study was conducted, involving 28 participants diagnosed with AxSpA. We evaluated clinical outcomes (perceived pain, range of motion [RoM], pressure pain threshold [PPT], and proprioceptive acuity), psychosocial outcomes (the Pain Catastrophizing Scale [PCS], Tampa Scale of Kinesiophobia [TSK-11], and the Fear-Avoidance Beliefs Questionnaire [FABQ]), and AxSpA-specific indices (the Bath Ankylosing Spondylitis Metrology Index [BASMI], Bath Ankylosing Spondylitis Functional Index [BASFI], and Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]). Data were analyzed using Spearman’s correlation coefficients and simple and multiple linear regression models. Results: Cervical and lumbar RoM values were reduced compared to established normative values for the general population. Significant associations were found between perceived pain, pain catastrophizing, and FABQ scores with both BASDAI and BASFI (p < 0.05). The interaction between perceived pain and pain catastrophizing (p < 0.001) accounted for 45.7% of the variance in BASDAI, while the interaction between perceived pain and FABQ (p < 0.001) explained 52.1% of the variance in BASDAI. Conclusions: The biopsychosocial profile of patients with AxSpA is characterized by moderate-intensity perceived pain and reduced cervical and lumbar mobility. The observed associations between BASDAI, pain catastrophizing, and fear-avoidance beliefs underscore the influence of psychosocial factors on disease progression. Full article

Fibromyalgia (FM) is characterized by persistent widespread pain that severely impacts quality of life. Immersive virtual reality-based exercise (iVRE) is emerging as a therapeutic modality for chronic pain management. However, research on iVRE in FM patients has primarily focused on perceived pain intensity (PI), with limited exploration of underlying analgesic mechanisms. This study aims to explore the effects of iVRE on PI, considering risk of poor outcomes (RPO) stratification, and on mechanical pain sensitivity (MPS) in FM. A single-arm, uncontrolled, pre-post-test exploratory study was conducted in subjects with FM. The intervention included 2 weekly 15-min iVRE sessions for 6 weeks. PI (numeric rating scale [NRS]) and MPS (pressure pain thresholds [PPTs] at the upper trapezius, lumbar spine, and knee) were assessed at baseline, after the first session (to assess exercise-induced hypoalgesia), and postintervention. RPO was assessed using the Keele STarT MSK Tool. Eleven participants completed the study. No adverse effects were reported. Clinically important reductions were observed in PI (mean difference [MD]: −2.36, 95% CI: [−4.15, −0.58], d = 0.89; p < 0.05) with this effect being associated with baseline RPO. No observable changes were found in PPTs (all 95% CIs included 0, p > 0.05). In this sample, iVRE appears to reduce PI but not PPTs, suggesting the persistence of MPS and limitations in activating endogenous pain inhibitory mechanisms. Further randomized controlled trials with larger samples are needed to corroborate these results. Full article

Background/Objectives: Fibromyalgia is a debilitating syndrome characterized by persistent pain. Emerging evidence highlights the role of emotional and cognitive processes in modulating pain experience. Anger, for example, can influence pain and patients’ adjustment to the disease. Studies showed that metacognitions and anger rumination can worsen state anger, thereby increasing perceived pain intensity. The present study aims to investigate the presence of a relationship between pain, dysfunctional metacognitions, anger rumination, and state anger. Methods: The study included 446 participants who self-reported having a diagnosis of fibromyalgia confirmed by a rheumatologist or pain specialist. Participants completed self-report measures of metacognitions, anger rumination, state anger, and pain intensity. The serial mediation analysis was performed using Hayes’ PROCESS macro (Model 6). Results: Pain intensity showed a significant positive effect on negative beliefs about worry (β = 0.09; p < 0.05), need to control thoughts (β = 0.09; p < 0.05), and cognitive self-consciousness (β = 0.12; p < 0.05), but not on anger rumination. Across all serial mediation models, the direct effect of pain intensity on state anger remained significant even after controlling for the effect of mediators, indicating partial mediation. Conclusions: This study suggests a vicious cycle involving dysfunctional metacognitions, anger rumination, state anger, and pain intensity. Our findings also indicate a potential influence of pain on metacognitions and suggest a direct association between pain intensity and state anger. Interventions for anger management in fibromyalgia should consider dysfunctional metacognitions and anger rumination. Full article

Background: Orthodontic treatment with fixed appliances often induces pain. Despite existing research on pain management, the dynamic nature of orthodontic pain and its relationship with tooth movement remain underexplored. This study surveys adults under fixed appliance therapy to investigate pain dynamics, modifying factors, and perceived tooth movement, aiming to provide insights for improved patient care and treatment outcomes. Methods: This study focused on healthy individuals aged 18 to 50 undergoing fixed appliance treatment for up to six months after having braces bonded. A 24-question survey was administered over a one-month period. The survey explored pain intensity, pain dynamics, modifying factors, and perceived tooth movement. Results: Pain typically began within the first few hours after bonding and peaked the following day for most respondents. The upper incisors and molars were the most frequently reported areas of pain, corresponding to the teeth perceived as moving earliest. Chewing was identified as the primary external pain trigger. Gender significantly influenced pain perception, with women reporting higher pain levels and greater use of medication. The majority of participants managed without medication. Conclusions: Pain during the early phase of fixed appliance therapy follows a predictable pattern, with peak intensity occurring on the day after bonding. Pain perception strongly correlates with early tooth movement, particularly in the upper incisors. Gender differences were evident, but other demographic factors had minimal influence. Chewing was the primary pain aggravator, emphasizing the need for dietary modifications. Understanding these findings can help orthodontists develop personalized pain management strategies. Full article

Background/Objectives: Approximately 30% of women experience pelvic pain one year after vaginal delivery, and this increases to 50% during vaginal intercourse. Multimodal physiotherapy is the first-line treatment for myofascial pain of the pelvic floor muscles (PFM), often incorporating emerging technologies like radiofrequency, despite limited evidence supporting its use. The RASDOP study aims to (i) evaluate the effectiveness of multimodal physiotherapy combining therapeutic education, PFM training, and myofascial pain syndrome (MPS) management with or without radiofrequency, in reducing pain and improving sexual function postpartum; and (ii) explore the barriers and facilitators influencing adherence and perceived self-efficacy towards physiotherapy treatment in women with postpartum pelvic pain. Methods: This study employs a randomized clinical trial with a blinded examiner and two parallel groups, followed by a qualitative phenomenological study. A total of 124 postpartum women with pelvic pain (≥4 cm on the visual analogue scale) will be randomized into two groups: a multimodal physiotherapy group (therapeutic education, MPS treatment, and PFM training) and a radiofrequency + multimodal physiotherapy group (same treatment with additional non-ablative radiofrequency). Both groups will receive 12 supervised individual sessions. Assessments will be conducted pre- and post-intervention, and at 3-, 6-, and 12-month stages post-treatment. Primary outcomes include pain intensity and sexual function, while secondary outcomes involve PFM tone, strength, MPS presence, levator ani length, and distress caused by pelvic floor dysfunction. The qualitative study will utilize semi-structured interviews and focus groups analyzed thematically. Results: Radiofrequency is expected to enhance pain relief, sexual function, and PFM relaxation. Insights into adherence and barriers will aid in personalizing physiotherapy interventions. Conclusions: The RASDOP study will provide evidence on the safety and efficacy of radiofrequency in postpartum pelvic pain treatment and shed light on women’s experiences to improve therapeutic outcomes. Full article

Background/Objectives: Fake pain expressions are more intense, prolonged, and include non-pain-related actions compared to genuine ones. Despite these differences, individuals struggle to detect deception in direct tasks (i.e., when asked to detect liars). Regarding neural correlates, while pain observation has been extensively studied, little is known about the neural distinctions between processing genuine, fake, and suppressed pain facial expressions. This study seeks to address this gap using authentic pain stimuli and an implicit emotional processing task. Methods: Twenty-four healthy women underwent an fMRI study, during which they were instructed to complete an implicit gender discrimination task. Stimuli were video clips showing genuine, fake, suppressed pain, and neutral facial expressions. After the scanning session, participants reviewed the stimuli and rated them indirectly according to the intensity of the facial expression (IE) and the intensity of the pain (IP). Results: Mean scores of IE and IP were significantly different for each category. A greater BOLD response for the observation of genuine pain compared to fake pain was observed in the pregenual anterior cingulate cortex (pACC). A parametric analysis showed a correlation between brain activity in the mid-cingulate cortex (aMCC) and the IP ratings. Conclusions: Higher IP ratings for genuine pain expressions and higher IE ratings for fake ones suggest that participants were indirectly able to recognize authenticity in facial expressions. At the neural level, pACC and aMCC appear to be involved in unveiling the genuine vs. fake pain and in coding the intensity of the perceived pain, respectively. Full article

Measuring exercise intensity for safety and to inform prescription in acute burn survivors, is challenging. This study aimed to assess the validity of adult patient end-of-workout rating of session perceived exertion (sRPE); and calculated training load (TL) (sRPE × session duration) as measures of exercise intensity. Secondly, the study aimed to compare clinician and patient perception of exercise effort during physiotherapist-led sessions. Repeated RPE data were collected every 5-min during two resistance exercise sessions completed by 25 burns patients. Physiological (heart rate [HR], blood lactate [BLa]) and perceptual measures (sRPE, ratings of pain, fatigue, delayed onset muscle soreness, sleep quality and stress) were also captured. Adjusted, multivariable linear regression models were used to determine the associations between sRPE and TL and significant predictor variables. Paired t-tests were performed to compare clinician and participant sRPE. Results: Average RPE calculated from 5-min repeats, after adjustment for age and %TBSA, was significantly associated with sRPE, F(1, 45) = 100.82, (p < 0.001, adjusted R² = 0.64) and TL, F(1, 45) = 33.66, (p < 0.001, adjusted R² = 0.39). No significant differences between patient and clinician sRPE were apparent (p = 0.948). Thus, one-off reporting of sRPE and calculated TL may be appropriate markers to monitor exercise intensity and aid prescription in individuals with burn injuries, regardless of patient and burn characteristics or time since burn. There was also no difference between patient and clinician’s perceptions of exercise effort. Full article

Introduction: PNE, focusing on cognitive aspects, aims to change patients’ beliefs about pain. However, it is unclear if these cognitive changes are sufficient to influence other components such as neuroplastic changes. Objective: To assess whether 3-h pain neuroscience education (PNE) can induce changes in brain-derived neurotrophic factor (BDNF) levels and pain intensity in chronic pain patients. Methods: A double-blind randomized clinical trial was conducted with 66 participants aged 18–65 years old (50.86 ± 8.61) with chronic primary musculoskeletal pain divided into two groups: an intervention group receiving 3-h PNE lecture and a control group that received an educational booklet. Primary outcomes included plasma BDNF levels and perceived pain intensity (VAS). Secondary outcomes included anxiety (HADS-A), depression (HADS-D), catastrophizing (PCS), kinesiophobia (TSK), stress (PSS), and knowledge about pain. Measurements were taken in both groups before and after a three-hour intervention. Data were analyzed using paired t-tests and Cohen’s d for effect sizes. Results: The results showed no significant changes in BDNF levels for the PNE lecture group (p = 0.708) or the educational booklet group (p = 0.298). Both groups showed significant reductions in pain intensity (PNE: p < 0.001, d = 0.70; booklet: p = 0.036, d = 0.39). Secondary variables, such as knowledge (PNE: p < 0.001, d = −0.972; booklet: p < 0.001, d = −0.975) and anxiety (PNE: p < 0.001, d = 0.70; booklet: p = 0.035, d = 0.39), also showed significant improvements. Conclusions: PNE did not significantly change BDNF levels but effectively improved pain intensity, pain-related knowledge, and other clinical variables. These findings suggest that while PNE has cognitive benefits, it may not be sufficient to induce immediate neurobiological changes. Further research is needed to explore long-term effects and incorporate additional therapeutic domains. Full article