Pressure Pain Threshold Research Articles

Selective nociceptive modulation using a novel prototype of transcutaneous kilohertz high-frequency alternating current stimulation: a crossover double-blind randomized sham-controlled trial.

Kilohertz high-frequency alternating current (KHFAC) stimulation has demonstrated to induce rapid and reversible nerve blocks without causing nerve damage. Previous studies have explored frequency-dependent effects using a transcutaneous approach in humans from 5 to 20kHz. Nevertheless, its application in humans is limited by the lack of stimulators approved for frequencies above 20kHz. Therefore, this study aimed to assess the effects and safety of transcutaneous KHFAC stimulation using a novel prototype stimulator, comparing interventions at 30, 40, and 50kHz to sham stimulation on experimental pain, sensory, motor, and neurophysiological outcomes. A randomized, double-blind, sham-controlled crossover study involving 34 healthy participants was conducted. Four interventions (30, 40, 50kHz, and sham) were administered, and stimulation was applied for 20min to the median nerve of the non-dominant hand. A prototype stimulator capable of delivering frequencies between 1 and 50kHz, with a maximum peak-to-peak output current intensity of 400mA was designed. The intensity applied during the stimulation was below motor threshold, evoking a 'strong but comfortable' tingling sensation. Primary outcomes included heat pain threshold (HPT), pressure pain threshold (PPT), and adverse effects. The secondary outcomes included static two-point discrimination sensitivity, isometric pinch strength, and median sensory nerve action potential (SNAP). Compared with the sham stimulation, all the active interventions exhibited a significantly greater increase in the PPT during and immediately after the stimulation, while only a significant increase was observed at 40kHz (4.1N/cm2; 95%CI 0.3 to 7.9) at 15min post-intervention. Compared to sham stimulation, the 40kHz intervention had a significantly greater effect on the HPT at all time points, with the greatest difference (1.4°C; 0.6 to 2.1) occurring immediately post-intervention. Adverse effects during active interventions included petechiae, erythema, and itching, which resolved at 24h post-intervention. For secondary outcomes, only a significant reduction in the median SNAP velocity was observed in the sham stimulation group compared to the 50kHz group. Active KHFAC stimulation, particularly at 40kHz, delivered through a novel stimulator, effectively increased the PPT and HPT without affecting tactile or motor outcomes, inducing mild skin-related adverse effects. These findings have potential implications for people with pain-related pathologies. NCT05230836.

Active Neurodynamic Technique at Home in Patients with Knee Osteoarthritis: An Open Single Arm Clinical Trial

Background and Objectives: Knee osteoarthritis (KO) stands as the third leading cause of disability among the elderly, causing pain, reduced quality of life, and decreased functionality. The objective of this study is to assess the effects of an active neurodynamic technique programme at home on pain, quality of life, and function among individuals with KO. Materials and Methods: Thirty-five participants (69.7% women) aged ≥50 years with KO (Kellgren–Lawrence grades I–II) performed a femoral nerve mobilization programme at home for 6–8 weeks (20 repetitions per day). Pain intensity, using the numerical rating scale (NRS), pressure pain thresholds (PPTs), central sensitization inventory (CSI), temporal assessment, pain modulation, Knee Injury and Osteoarthritis Outcome Score (KOOS), and the 12-item Short Form Survey questionnaire (SF-12) were collected before, after the intervention, and at one, three, six, and twelve months. Results: Participants improved significantly in pain (p < 0.05), with the improvement maintained throughout the follow-up in the NRS and for at least one month in the PPT. There were also statistically significant (p < 0.05) improvements in all subscales of the KOOS, which were maintained throughout the follow-up. Improvements were also found in the CSI and CPM. Conclusions: A home-based active neurodynamic programme for the femoral nerve has been demonstrated to yield positive effects on pain and function in patients with KO.

Exploring signs of central sensitization in adolescents with hypermobility Spectrum disorder or hypermobile Ehlers-Danlos syndrome.

Hypermobility Spectrum Disorder (HSD) and Hypermobile Ehlers-Danlos Syndrome (hEDS) are two overlapping heritable connective tissue disorders characterized by joint hypermobility, chronic pain, impaired body perception, and musculoskeletal symptoms. Central sensitization has been proposed as a plausible explanation for symptoms like widespread pain, fatigue, mood disorders, and sleep disturbances in patients with HSD/hEDS. The aim of this study was to investigate signs of central sensitization, including exercise-induced hypoalgesia (EIH), and fatigue severity in adolescents with HSD/hEDS. In this prospective, experimental, case-control study, thirty-seven adolescents with HSD/hEDS and 47 healthy adolescents (all aged 13-17 years) were included. Pressure pain thresholds (PPTs) were measured at four muscle groups using a pressure algometer. EIH was evaluated by measuring PPTs on two muscle groups immediately after an exercise test on a bicycle ergometer. Participants also completed questionnaires on fatigue and cognitive/emotional factors. The study demonstrated significantly lower PPTs in four different muscle groups in adolescents with HSD/hEDS compared to the healthy control group. Both groups achieved a significantly higher PPTs after exercise in the muscle involved in the activity. Adolescents with HSD/hEDS reported higher fatigue levels and more cognitive/emotional difficulties than the control group. Adolescents with HSD/hEDS showed generalized hyperalgesia measured through PPTs at different body sites. EIH was partly affected in adolescents with HSD/hEDS, presenting as unchanged pain sensitivity in the remote muscle. Pain should be considered as a phenomenon that is influenced by different biopsychosocial factors, including possible central sensitization, which increase its complexity. This study breaks new ground by showing signs of central sensitization, including diminished EIH, in adolescents with HSD or hEDS. Given that exercise is a key element in pain management, these findings offer valuable insights when developing treatment plans for adolescents with HSD or hEDS.

Persistent postsurgical pain in hip fracture patients. A prospective longitudinal study with multifaceted assessment.

Some patients with postoperative hip fractures (HF) experience persistent severe pain. In this longitudinal study, we examined the characteristics of patients with persistent pain after HF surgery, and the factors influencing pain intensity. We conducted an 8-week prospective study in patients with postsurgical HF. Verbal rating scale (VRS), and multifaceted outcomes, including pressure pain threshold (PPT) (affected site and biceps), were evaluated at 2, 4, and 8 weeks postoperatively. Patients were divided into mild (VRS ≤1) and severe (VRS ≥2) groups according to pain intensity at 8 weeks postoperatively. Statistical analyses were performed using two-way ANOVA and decision-tree analysis. VRS, PPT at the affected site and biceps, and physical activity (PA) time were significantly lower in the severe group than in the mild group 2 weeks postoperatively. VRS, PPT at the affected site, pain catastrophizing (PCS)-13, and the Tampa Scale for Kineshiophobia (TSK)-11 did not show significant improvements in the severe group. Decision tree analysis revealed that the VRS and PCS-13 at 4 weeks, PA time at 2 weeks, and TSK-11 change between 4 weeks and 2 weeks were factors influencing severe pain intensity at 8 weeks after HF surgery. Persistent severe pain after HF surgery was characterised by high peripheral and central sensitisation, pain catastrophizing, and reduced PA at 2 weeks after HF surgery. In addition, early pain intensity, pain catastrophizing, and PA may be hierarchically influential factors for persistent pain 8 weeks after HF surgery.

Investigating the Effects of Shockwave and Percussion Massage Gun on Subacute Myofascial Pain in Gasterocenemious Muscle

Introduction: Myofascial pain syndrome is a common musculoskeletal injury, especially among athletes, typically treated with symptomatic invasive and non-invasive methods. This study compares the effects of massage guns and radial extracorporeal shock wave therapies on myofascial pain syndrome symptoms in amateur athletes. Materials and Methods: In this clinical trial, 45 amateur athletes (18-30 years old) were recruited, who were randomly assigned to 15-member groups of shock wave, massage gun, and control (routine treatment included electrotherapy and stretching, which was applied on three groups). After initial evaluations of the pain intensity, pain pressure threshold (PPT), isometric muscle strength, and range of motion (ROM), the patients received single-session treatment and were immediately reassessed. Results: The results showed pain relief and improved PPT following shock wave plus routine treatment (P=0.03). The control group had less pain, while pain intensity and PPT did not change. The variables were not significantly different between the groups (P=0.12). Shock wave along with routine treatment increased plantar flexion ROM (P=0.00), unlike the massage gun. Additionally, dorsiflexion ROM (P=0.63) and maximal isometric gastrocnemius muscle strength (P=0.95) remained unchanged in all groups. Conclusion: One session of massage gun therapy immediately reduced gastrocnemius muscle pain, while it failed to change PPT, maximal isometric gastrocnemius muscle strength, or dorsiflexion and plantar flexion ROM. However, shock wave therapy immediately increased plantar flexion ROM and PPT, and reduced pain intensity. These modalities led to limited changes, suggesting the need for repeated sessions and supplementary treatments.

Investigating the Effect of Dry Needling on Myofascial Trigger Point in Soleus Muscle of Soccer Players with Medial Tibial Stress Syndrome

Introduction: This study investigates the impact of dry needling on myofascial trigger points in the soleus muscles among soccer players with medial tibial stress syndrome (MTSS). Materials and Methods: Soccer players diagnosed with MTSS were enlisted and randomly divided into two groups (11 participants in the experimental group [Group 1] and 11 participants in the control group [Group 2]). Pre-intervention measurements included repeated shuttle sprint ability, MTSS score, and pain pressure threshold (PPT) for both groups. In the experimental group, dry needling was performed on the soleus muscle, followed by active stretching and cryotherapy. The control group underwent active stretching of the soleus muscle and cryotherapy exclusively. Post-intervention measurements of repeated shuttle sprint ability, MTSS score, and PPT were taken for both groups after 2 days. Results: The experimental group exhibited a statistically significant improvement in PPT, MTSS score, and repeated shuttle sprint ability. Conversely, within the control group, statistically significant changes were observed only in PPT values through paired t-test assessment. Between-group analysis using an independent t-test revealed significant enhancement in PPT (P=0.000) and MTSS score (P=0.01) within the experimental group compared to the control group. Conclusion: Addressing myofascial trigger points in the soleus muscle through dry needling offers a more effective approach to treating MTSS than relying solely on muscle stretching.

Effect of Lingual Nerve Block and Localised Somatosensory Abnormalities in Patients With Burning Mouth Syndrome-A Randomised Crossover Double-Blind Trial.

To investigate the effect of a lingual nerve block on spontaneous pain in patients with burning mouth syndrome (BMS) and to estimate associated somatosensory abnormalities by quantitative sensory testing (QST). A standardised QST battery including cold detection threshold (CDT), warmth detection threshold (WDT), thermal sensory limen (TSL), paradoxical heat sensation (PHS), cold pain threshold (CPT), heat pain threshold (HPT), mechanical pain threshold (MPT), wind-up ratio (WUR) and pressure pain threshold (PPT) was performed at the oral mucosa of the most painful site and intraoral control site in 20 BMS patients, and at the tongue and cheek mucosa in 22 age- and gender-matched healthy controls. The effect of a lingual nerve block on spontaneous burning pain reported by the BMS patients on a 0-10 cm visual analogue scale (VAS) was investigated in a randomised double-blind crossover design using (1 mL) lidocaine (lido) or saline (sal) with an interval of 1 week. The BMS patients were grouped into 'central' and 'peripheral' mechanisms based on the effect of the lingual nerve injections. For each BMS patient, Z-scores and Loss/Gain scores were computed. Differences among groups and sites were analysed using a two-way ANOVA. Differences within group were assessed by paired t-test. The 20 BMS patients were characterised on the basis of VAS changes (ΔLido-ΔSal) as a peripheral BMS subgroup (n = 9) with pain relief more than 1 cm on the VAS and a central BMS subgroup (n = 11) with pain relief less than 1 cm. BMS patients (n = 20) had lower sensitivity to thermal stimuli (i.e., CDT, WDT, TSL, CPT, HPT and PPT) and higher sensitivity to mechanical stimuli (i.e., PPT) compared with controls (p ≤ 0.007). Based on Loss/Gain coding, L1G0 (loss of thermal somatosensory function with no somatosensory gain, 55.0%) was the most frequent coding in the BMS group, which was higher than 11.4% in the control group (p < 0.001). Surprisingly, there was no significant difference between the peripheral and central BMS subgroups with regard to the Z-scores of any of the nine QST parameters (p > 0.097). The results of the lingual nerve blocks demonstrated two distinct phenotypes with either peripheral or central mechanisms but no direct impact on somatosensory function. Overall, somatosensory function in BMS patients seems abnormal in the painful areas compared to matched controls with a conspicuous loss of thermosensory function.

Do measures of central sensitization relate to movement-evoked pain in people with chronic low back pain? A longitudinal prospective study

BackgroundOne of the most frequent complaints among people with musculoskeletal pain is pain during physical activity, commonly referred to as movement-evoked pain. It is suggested to be associated with quantitative sensory testing measures of central pain process in individuals with musculoskeletal pain. ObjectiveTo investigate the predictive association between movement-evoked pain scores and measures of central sensitization in patients with chronic nonspecific low back pain. The secondary aim was to determine whether changes in movement-evoked pain scores are associated with changes in measures of central sensitization. MethodsIn this longitudinal prospective study, 50 participants with chronic low back pain were included. Pain pressure thresholds, temporal summation of pain, descending pain modulation, and the central sensitization index were assessed as measures of central sensitization. Movement-evoked pain was evaluated using the Back Performance Scale and a 5-minute walk test. ResultsMeasures of central sensitization, specifically pressure pain thresholds and temporal summation, demonstrated predictive associations with movement-evoked pain measures. In response to treatment, improvements in movement-evoked pain were associated with improvements in measures of central sensitization (i.e., pressure pain thresholds and temporal summation) and improved pressure pain thresholds in the plantar toe significantly predict movement-evoked pain measures experienced during the 5-minute walk test. ConclusionsThese results imply that movement-evoked pain is related to processes related to central modulation of pain in patients with nonspecific chronic low back pain.

Good vibes for the brain - Placebo versus real vibration in patients with chronic neck pain: A randomized cross-over study

BackgroundNeck muscle vibration decreases pain and improves sensorimotor impairments in patients with chronic neck pain. However, the impact of placebo on these effects are still unclear. ObjectiveThe aim was to evaluate the effect of neck muscle vibration compared to placebo neck muscle vibration in patients with chronic neck pain. MethodsTwenty-three people with chronic neck pain participated in this double-blinded, randomized crossover study. After baseline assessment at day 1, patients received either neck muscle vibration or placebo neck muscle vibration at day 2. At day 3, patients underwent the other treatment. The primary outcomes assessed at each day were active cervical joint position sense acuity, resting pain, and pressure pain threshold. ResultsCervical joint position sense revealed a significant time effect (F1, 22 = 4.366, p = 0.016, η2 = 0.902). Post-hoc testing revealed significant increases in cervical joint position sense after neck muscle vibration (p = 0.023; d = 0.602) but not after placebo vibration. Resting pain (F1, 22 = 7.550, p = 0.003, η2 = 0.418) displayed significant time effects for neck muscle vibration and placebo vibration. Pressure pain threshold demonstrated a significant time to condition effect (F1, 22 = 6.146; p = 0.008, η2 = 0.369). Post-hoc tests revealed that only neck muscle vibration significantly increased pressure pain threshold (p = 0.043, d = 0.516). ConclusionThe study demonstrates the efficacy of neck muscle vibration to decrease neck pain and improve cervical joint position sense in patients with chronic neck pain. Nevertheless, the influence of placebo effects should not be underestimated as they may contribute to these effects, indicated by similar decreases in resting pain.

Development and Testing of a Device to Detect Trigger Points, and Local Twitch Responses in Dry Needling Intervention

Trigger point dry needling (TrpDN) has emerged as a promising intervention for the treatment of myofascial pain. This involves insertion of a sterile filament needle directly into the trigger point (Trp), with the aim of eliciting a local twitch response (LTR). This sudden, involuntary contraction of the muscle fibers confirms the breakdown and success of TrpDN intervention. Not all LTRs are perceptible through visual observation or tactile sensation during the intervention. In search of noticeable LTR, clinicians perform Hong's technique (back-and-forth movements of needle in muscle). This results in muscle damage and causes pain and discomfort thereby limiting functional movements of patients. One important factor in the diagnosis and post intervention follow-up of TrpDN is the pain pressure threshold (PPT). Currently most of the clinicians use thumb pressure and subjective scales for confirming trigger points. These methods can introduce biasness due to its reliance on subjective factors.•In this present study, an effort has been made to assemble a device to overcome the challenges faced during assessment and treatment of trigger points.•This device can provide audiovisual feedback for LTR and can measure PPT.

Clinical Cues for the Early Diagnosis of Transthyretin-Related Polyneuropathy.

The estimated prevalence of hereditary transthyretin-related familial amyloid polyneuropathy (TTR-FAP) and the small number of known patients in Germany indicate that many patients with TTR-FAP remain undiagnosed, and may instead be classified as "idiopathic." The aim of this study was to identify biomarkers for detecting TTR-FAP among a cohort of patients with idiopathic polyneuropathy (PNP). Clinical evaluations (including the Neuropathy Impairment Score and Neuropathy Disability Score), nerve conduction studies (NCSs), quantitative sensory testing, and autonomic function tests were performed on 23 patients with TTR-FAP and 89 with idiopathic PNP. Discriminant analysis was then performed to identify variables useful for predicting TTR-FAP. Patients with TTR-FAP had paresis of the finger and thumb muscles, and reduced vibration perception and increased pressure pain in the upper and lower extremities. The NCSs showed that action potentials were smaller in the median, ulnar (both motor and sensory), and sural nerves in TTR-FAP. The sensory nerve conduction velocity was also reduced in the ulnar nerve. Autonomic neuropathy was confirmed by reduced sympathetic skin responses in the hands and feet in TTR-FAP. Multivariate discriminant analysis revealed that finger abduction strength, sensory ulnar nerve action potential amplitude, and vibration detection and pressure pain thresholds in the upper extremities were sufficient to correctly identify TTR-FAP in 81.3% of cases. Detailed clinical and neurophysiological investigations of standard parameters in the upper limb may help to identify the otherwise-rare TTR-FAP.

The effects of photobiomodulation and transcutaneous electrical nerve stimulation on chronic neck pain: A double-blind, randomized, sham-controlled trial

BackgroundPhotobiomodulation (PBM) and transcutaneous electrical nerve stimulation (TENS) are used to reduce neck pain. ObjectiveTo investigate the immediate and 1-month post-treatment effects of 10 treatment sessions of PBM and TENS delivered over 2 weeks on pain intensity in individuals with neck pain. MethodsIndividuals with neck pain were randomized into four groups: PBM+TENS, PBM, TENS, and Sham. Primary outcome: pain intensity at rest. Secondary outcomes: pain intensity during movement, pressure pain threshold (PPT), temporal summation (TS), conditioned pain modulation (CPM), cervical range of motion (ROM), psychosocial factors, drug intake for neck pain, and global perceived effect (GPE). All outcome assessments were made pre- and post-treatment. Mean differences and 95 % confidence intervals were calculated for between-group comparisons. ResultsA total of 144 participants were recruited. No significant between-group difference was observed for pain intensity at rest, TS, CPM, ROM, psychosocial factors, and drug intake. The PBM+TENS showed a reduction in pain intensity during movement and GPE compared to the PBM (MD: 1.0 points; 95 % CI: 0.0, 2.0; MD: 2.0 points; 95 % CI: 1.0, 3.0) and Sham (MD: 2.0 points; 95 % CI: 1.0, 3.0; MD: 2.0 points; 95 % CI: 1.0, 3.0) groups. PBM+TENS presented a medium effect size to increase local PPT compared to PBM and Sham groups. TENS presented a medium effect size to increase local PPT compared to PBM and Sham groups. TENS presented a medium effect size to increase distant PPT compared to other groups. ConclusionsThe use of PBM or TENS was not effective for reducing pain intensity at rest. The combination of PBM and TENS was effective in improving pain intensity during movement, local hyperalgesia, and the GPE. TENS reduced local and distant hyperalgesia.

Transcranial Direct Current Stimulation Reduces Pressure Pain Sensitivity in Patients With Noncancer Chronic Pain.

Noncancer chronic pain is a clinical challenge because pharmacological treatment often fails to relieve pain. Transcranial direct current stimulation (tDCS) is a treatment that could have the potential for pain relief and improvement in quality of life. However, there is a lack of clinical trials evaluating the effects of tDCS on the pain system. The aim of the present study was to evaluate the effect of 5 days of anodal tDCS treatment on the pain system in patients with chronic noncancer pain using quantitative sensory testing and quality of life questionnaires: (1) Brief Pain Inventory-short form, (2) European Organization for Research and Treatment of Life Questionnaire-C30, and (3) Hospital Anxiety Depression Scale. Eleven patients with noncancer chronic pain (51 ± 13.6 y old, 5M) participated in the study. Anodal tDCS was applied for 5 consecutive days, followed by sham stimulation after a washout period of at least 2 weeks. Pressure pain thresholds and pain tolerance thresholds (PTT) were assessed in different body regions on days 1 and 5. Anodal tDCS appeared to maintain PTT at C5 (clavicle) on day 5, but sham stimulation decreased PTT ( P = 0.007). In addition, anodal tDCS increased PTT compared with sham at day 5 at Th10 ventral dermatomes ( P = 0.014). Both anodal and sham tDCS decreased the Brief Pain Inventory-short form total and interference scores, and the European Organization for Research and Treatment of Life Questionnaire-C30 fatigue score, but no interaction effect was observed. This study adds to the evidence in the literature that tDCS may be a potential therapeutic tool for the management of noncancer chronic pain.

A biopsychosocial approach to phenotyping people with knee osteoarthritis awaiting total knee arthroplasty: A secondary cohort analysis

BackgroundPrevious research showed chronic post-total knee arthroplasty (TKA) pain in 20% of people with knee osteoarthritis (KOA). Various preoperative biopsychosocial-related factors have been described, but phenotyping people with KOA awaiting TKA based on these factors is still lacking. This could be relevant to understanding differences in TKA surgery responses. ObjectiveTo identify phenotypes in people with KOA awaiting TKA and differences in post-TKA pain based on preoperative biopsychosocial factors. MethodsPeople with KOA awaiting TKA in 4 hospitals in Belgium and the Netherlands were included. A cross-sectional latent profile analysis was conducted on structural, metabolic, functional, pain-related, psychological and social variables. Concurrent validity was tested using 3-step multinomial logistic regression. The difference in one-year post-TKA pain was examined with linear mixed model analysis. ResultsTwo hundred and seventeen participants were included in the latent profile analysis with a mean (SD) age of 65.5 (7.7) years, including 109 women. A model with 2 phenotypes differed in 14 out of 21 variables. Participants with phenotype 2 (28%) had a higher body mass index (BMI), higher chance of having less structural damage (KOA grade), lower mean quadriceps strength and physical function (Knee Society Scoring System functional and 30-second chair stand test), higher pain intensity, number of pain locations, and indices of central sensitisation (temporal summation, central sensitisation inventory score, and lower pressure pain thresholds), higher pain catastrophising, anxiety and depression, and higher post-TKA pain intensity compared to phenotype 1 (72%). Concurrent validity was confirmed in 3 out of 4 variables. ConclusionsPhenotype 2 (28%) with nociplastic pain characteristics in combination with worse psychological factors, BMI, functional and structural factors, and phenotype 1 (72%) not representing these characteristics were identified. Phenotype 2 had worse pain intensity scores after TKA compared to phenotype 1. Attention to the characteristics of phenotype 2 is warranted concerning post-TKA pain. Database registrationThe protocol is registered at ClinicalTrials.gov (NCT05380648).

Acupuncture combined with Chinese herbal medicine for discogenic low back pain: protocol for a multicentre, randomised controlled trial

IntroductionDiscogenic low back pain is a common form of chronic low back pain. In traditional Chinese medicine, combinations of acupuncture and herbal medicine are frequently used to manage this condition....

The Relationship Between the Elastic Properties and Pain Pressure Threshold in Cesarean Scar Tissue-An Observational Study.

Cesarean section (C-section) scars can lead to chronic pain due to changes in tissue properties. Combining elastography and algometry can assess these scars comprehensively by identifying areas of increased rigidity and quantifying pain sensitivity. This study aims to evaluate the efficacy of using elastography and algometry together to assess cesarean scar tissue, correlating tissue stiffness with pain thresholds for targeted pain management. Thirty-one non-pregnant women who had undergone a C-section between six months and two years prior participated. Elastography measured tissue stiffness, while algometry provided quantitative measures of pain sensitivity on and around the scar. The correlation between tissue stiffness and pain thresholds was analyzed. Elastography identified areas of increased rigidity within the scar tissue, which corresponded with lower pain thresholds measured by algometry, indicating higher pain sensitivity. A significant correlation was found between increased tissue stiffness and reduced pain thresholds (p < 0.05). Combining elastography and algometry offers a powerful diagnostic tool for evaluating C-section scars. This approach identifies areas that may benefit from targeted pain management interventions, enhancing understanding and treatment of pain associated with cesarean scars. Incorporating these techniques into clinical practice could improve patient outcomes and quality of life.

Effectiveness of Percutaneous Electrical Nerve Stimulation on Range of Motion, Pain Pressure Threshold in the Management of Myofascial Trigger Point: A Systemic Review

This review of randomized controlled trials sought to evaluate the efficacy of Percutaneous Electrical Nerve Stimulation (PENS) on range of motion, pain, and pain pressure threshold, as well as to investigate the specific factors influencing its effectiveness. The search for relevant studies published between 2017 and 2024 was conducted in PubMed, Scopus, The Cochrane Library, and the Physiotherapy Evidence Database. Fifteen studies met the inclusion criteria, with primary outcomes focusing on pain, range of motion, and quality of life. The findings indicate that percutaneous Electrical Nerve Stimulation (PENS) is effective in providing short-term pain relief, improving range of motion, and enhancing quality of life when compared to no intervention, sham, or placebo treatments. However, there is insufficient evidence regarding its impact on disability, analgesic medication intake, and sleep quality. In conclusion, while some evidence supports the short-term benefits of Percutaneous Electrical Nerve Stimulation (PENS), further high-quality randomized clinical trials with standardized procedures are necessary.

Effects of Vegan and Omnivore Diet on Post-Downhill Running Economy and Muscle Function

Objectives The objective of this study was to examine the difference between the extent of muscle damaging exercise on muscle function variables of vegans and omnivores. Methods Twenty recreationally trained participants completed the study. Participants were assigned to either vegan (n = 10) or omnivore (n = 10) groups. Subjects completed a consent visit followed by 2 visits consisting of running exercise sessions and test familiarization. They returned to the laboratory for visit 4 3-5 days after visit 3 to complete the testing battery. Following the testing, the participants performed a downhill run on the treadmill at −15% grade and approximately 70% of their speed at VO2peak and repeated the testing battery upon completion. Participants were asked to track their food intake. Visits 5, 6, and 7 took place 24, 48, and 72 h following the downhill running protocol, respectively, and consisted of the same testing battery used during visit 4. The detection of differences was performed using two-way (group x time) mixed factorial ANOVA with repeated measures. Results No group x time interactions were noted for running economy or any of the dependent variables. Main effects of time were found for muscle thickness (p<.001) with small effect sizes (d=-0.194 to d=-0.265), pain pressure threshold (p=.002) with medium effect sizes (d=.460 to d=.461), NPRS scale (p<.001) with large effect sizes (d = -0.776 to d=-1.520), and jump height (p<.002) with small to medium effect sizes (d=.304 to d=.438). Nutritional analysis compared the two groups revealed no difference (p>.05) between relative intake of macronutrients and that both exceeded typical recommendations for protein (vegan group − 1.4 g/kg, omnivore group − 1.6 g/kg). Conclusion The lack of differences in recovery between the groups suggests that nutritional adequacy may play a role in recovery. Recovery from downhill running might be influenced by several factors beyond diet, such as exercise protocol intensity, individual fitness levels, and age.

Effects of Apnea-Induced Hypoxia on Hypoalgesia in Healthy Subjects

Introduction: Exercise-induced hypoalgesia is a phenomenon in which exercise bouts induce a reduction in pain sensitivity. Apnea training involves similar characteristics that could potentially induce hypoalgesia. Objectives: The objectives of this study are to explore the effect of apnea training on hypoalgesia; assess the correlation between conditioned pain modulation (CPM) response and apnea-induced hypoalgesia; and examine the association between hypoalgesia with hypoxemia, and heart rate (HR) during apnea. Methods: A randomized controlled trial was conducted comparing a walking protocol employing intermittent apnea compared with normal breathing in healthy volunteers. Hypoalgesia was tested with pressure pain thresholds (PPTs) and CPM. Oxygen saturation (SpO2) and HR were also tested. Results: Relevant but not significant changes were detected in the thumb (MD = 0.678 kg/cm2), and tibialis (MD = 0.718 kg/cm2) in favor of the apnea group. No significant differences were detected in CPM. The apnea group presented lower SpO2, but HR values similar to those of the control group during the intervention. Basal CPM and intrasession hypoxemia significantly correlated with the PPT response. However, HR did not correlate with the PPT response. Conclusions: The current results suggest a trend, though not statistically significant, toward an improvement in the PPT in favor of apnea training compared to normal breathing. Nevertheless, subjects who presented greater basal CPM and lower oxygen saturation during the session presented a greater PPT response, suggesting the possibility of mediators of response. Future investigations should clarify this phenomenon.

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

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. 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. 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. 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. 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.