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The association of localized pain sensitivity in the residual limb and prosthesis use has clinical implications, however, rarely been assessed. This study aimed to investigate pain sensitivity and explore its range, variability, and association with prosthesis use alongside other demographic and clinical characteristics of veterans with transtibial amputation. Pain sensitivity was determined as pressure pain threshold (PPT) and pressure tolerance (PT) in 19 male veterans with a mean age of 49.5 years using pressure algometry at 12 anatomical locations on the residual limb. A comparison of pain sensitivity at each location, and among anatomical locations and participants was explored using independent t-test, analysis of variance, and Kruskal--Wallis tests, respectively. Pain sensitivity range (PSR), the difference between PT and PPT, was significantly different (p < 0.05) at mid-patellar tendon, medial tibial flare, and the distal end of the tibia. The lowest PPT and PT (20.5 and 33 Ncm-2, p = 0.13) were recorded at the distal end of the residual limb, and the highest PPT and PT (73.4 and 94.3 Ncm-2, p = 0.03) were recorded at the mid-patellar tendon. Pain sensitivity was significantly different among anatomical locations and participants. The correlation tests (Pearson and partial eta squared) showed non-significant associations of pain sensitivity with participants' demographic and clinical characteristics except for daily prosthesis use. The mid-patellar tendon, medial tibial flare, and distal end of the tibia revealed the lowest pain hypersensitivity due to higher PSR. Longer daily prosthesis use was associated with increased pain sensitivity. [ABSTRACT FROM AUTHOR]

Pain at the injection site is the most frequent reaction among COVID-19 vaccine recipients, but its characteristics were not fully described yet. The purpose of this study was to investigate multiple domains of pain following BNT162b2 mRNA vaccination. We included 107 subjects undergoing primary shot of the vaccination twice into deltoid muscle with a 3-week interval. They completed 6 sessions of pain assessments, one before the first and second dose (1-0, 2-0), and 1st / 7th day after the first and second dose (1-1 / 1-7, 2-1 / 2-7). Pain visual analog scale (VAS), pain distribution, and pressure pain threshold (PPT) on deltoid muscle were evaluated in each session. The mean VAS (at rest / shoulder motion) was 6.0 / 27.6 mm at 1-1, and 12.8 / 34.0 mm at 2-1. Approximately, 90% of recipients showed localized pain within the upper arm. Percentage change of PPTs at 1-1 and 2-1 was bilaterally (ipsilateral / contralateral) decreased to 87.4 / 89.4% and 80.6 / 91.0%, which was recovered to the baseline level at 1-7 and 2-7. Temporary, mild-to-moderate intensity, localized distribution, concomitant with bilateral mechanical hyperalgesia on the deltoid muscle, were typical pain characteristics following this vaccination. These findings provide a rationale that will be informative for future recipients. [ABSTRACT FROM AUTHOR]

Prayer is considered to be the most common therapy used in alternative medicine. This study aimed to explore the effect of prayers on endogenous pain modulation, pain intensity, and sensitivity in healthy religious participants. A total of 208 healthy religious participants were enrolled in this study and randomly distributed into two groups, a prayer group (n = 156) and a poem reading or control group (n = 52). Participants from the prayer group were then selectively allocated using the prayer function scale to either an active prayer group (n = 94) receiving an active type of praying or to a passive prayer group (n = 62) receiving a passive type of praying. Pain assessments were performed before and following the interventions and included pressure pain threshold assessment (PPT), conditioned pain modulation (CPM), and a numerical pain rating scale. A significant group-by-time interaction for PPT (p = 0.014) indicated post-intervention increases in PPT in the prayer group but not in the poem reading control group. Participants experienced a decrease in CPM efficacy (p = 0.030) and a reduction in their NPRS (p < 0.001) following the interventions, independent of their group allocation. The results showed that prayer, irrespective of the type, can positively affect pain sensitivity and intensity, but does not influence endogenous pain inhibition during hot water immersion. Future research should focus on understanding the mechanism behind "prayer-induced analgesia." [ABSTRACT FROM AUTHOR]

Comparing the Effects of Home-Based McKenzie and Back School Exercises on Pain, Flexibility, Range of Motion, and Disability in Patients with Non-Specific Chronic Low Back Pain: A Randomized Controlled Trial. JEPonline 2023;26(3):107-121. Non-specific chronic low back pain refers to lower back and lumbar region pain that lasts more than 12 weeks. This condition can lead to reduced trunk movement and activities of daily living. Exercises, especially McKenzie exercises and back school exercises, are a potential treatment for non-specific chronic low back pain. However, comparing the effects of these two types of exercise is still limited. The purpose of this study was to compare the effects of home-based McKenzie and back school exercises on the pain scale, pressure pain threshold (PTT), back flexibility, range of motion (ROM) of the lumbar spine, and disability in patients with non-specific chronic low back pain. A total of 40 non-specific chronic low back pain patients 30 to 65 years of age were randomly assigned to perform McKenzie exercises (n = 20) or back school exercises (n = 20). All participants in both groups performed the exercises at home for 45 minutes per day for 4 weeks. The parameters such as pain scale, PTT, back flexibility, ROM of the lumbar spine, and disability were evaluated at baseline and after the above-described exercise. The above-listed outcomes were measured via a numerical pain rating scale (NPRS), a digital pressure algometer, a Flex-meter, a fluid inclinometer, and the Roland-Morris Disability Questionnaire, respectively. Statistical significance was regarded at an alpha level of P<0.05. Four weeks of home-based McKenzie and back school exercises showed that participants in both groups reduced pain scales, increased pressure pain thresholds, improved back flexibility, and improved disability. The McKenzie exercise group showed significant improvement in ROM of the lumbar spine in all directions except right lateral flexion. However, the Back School Exercise Group showed no significant improvement. There was no significant difference between the 2 Groups except, the McKenzie Exercise Group had a greater improvement in ROM of the right and left lumbar lateral flexion (P = 0.041 and P = 0.048). In conclusion, McKenzie exercise and back school exercise was found to reduce the pain scale, increase the pressure pain threshold, as well as improve back flexibility and disability. Interestingly, the McKenzie exercise improved lumbar spine ROM more than the back school exercise. [ABSTRACT FROM AUTHOR]

Zheng Y, Zhu R, Xiao C, et al. J Pain Res. 2023;16:2205–2216. The authors have advised that they neglected to include a funding statement on page 2215 of the published paper. The funding statement should read as follows. Funding This work was supported by the Technology Innovation Project of Science and Technology Bureau of Chengdu (2022-YF05-01691-SN) and Clinical Research Project of West China Hospital of Stomatology, Sichuan University (LCYJ-2023-YY-2). The authors apologize for this error.

Background: Persistent neck pain is a prevalent musculoskeletal condition that affects the quality of life and functional abilities of individuals. Blood Flow Restriction Training (BFRT) is a novel therapeutic approach that involves restricting blood flow to exercising muscles to enhance strength and function. However, limited research has been conducted on the effects of BFRT on pressure pain threshold and hand function in adults with persistent neck pain. This randomized controlled trial aims to investigate the potential benefits of BFRT as a treatment intervention for this population. Methods: This study will be a prospective parallel group active controlled trail done at Physiotherapy Department, Galgotias University. Ethical clearance has been obtained from Departmental Ethics Committee on 19/05/2023 with reference number DEC/PT/GU/2023 and the Trial has been registered with Clinical Trial Registry India CTRI/2023/06/053439. Informed consent will be obtained from all the participants who are eligible to be included in the study. 110 patients with persistent neck pain will be randomly allocated into two groups. The BFRT group will receive supervised training sessions three times a week for eight weeks, performing low-load resistance exercises with blood flow restriction applied using personalized cuff pressure. The control group will receive standard care for neck pain, which may include general advice, manual therapy, and/or home exercises without BFRT. The primary outcome measures will be the pressure pain threshold, assessed using a pressure Algometer, and hand function, evaluated using standardized tests such as Hand Grip Strength and Purdue Peg board Test. Results: The data obtained will be analyzed using appropriate statistical methods, and the significance level will be set at p Conclusion: This trial will contribute valuable contribution highlighting the potential benefits of BFR training in improving pressure pain threshold and hand function in adults with persistent neck pain.

Objective: To evaluate the short-term efficacy and safety of cold compression therapy (CCT) relative to a soft padded bandage (SPB) in dogs undergoing surgery to manage cranial cruciate ligament injury. Methods:Dogs were randomized into groups that received CCT or SPB after surgery. Weight bearing was measured using a weight distribution platform before and the day after surgery. Stifle joint flexion and extension were measured using a goniometer before and the day after surgery. Rectal temperatures were measured every 15 min for 2 h after surgery and the morning after surgery. Mechanical nociceptive thresholds (MNT) were measured using an algometer the day after surgery. Findings in both groups were compared using a mixed model ANOVA. Results:20 dogs were enrolled: 10 in the CCT and 10 in the SPB group. Dogs undergoing CCT had more stifle joint flexion (P = 0.008) and weight bearing (P < 0.001) after surgery than dogs with SPB. MNT after surgery correlated statistically with stifle joint flexion after surgery (r = -0.315, P = 0.014), extension after surgery (r = 0.310, P = 0.016), and weight bearing after surgery (r = 0.314, P = 0.003). Return to normothermia was delayed in the CCT group, with temperatures ~0.5°C (1.0°F) lower 105 (P = 0.018) and 120 min (P = 0.013) after surgery. Conclusion:Relative to bandaging, CCT had a positive short-term impact on stifle flexion and weight bearing. CCT delayed warming after surgery but dogs were only mildly hypothermic [0.5°C [1.0°F]].

Experimental pain sensitivity was assessed in individuals with urologic chronic pelvic pain syndrome (UCPPS) as part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network. A series of computer-controlled pressure stimuli were delivered to the thumbnail bed, an asymptomatic site distant from the area of UCPPS pain that is considered to be indicative of overall body pain threshold. Stimuli were rated according to a standardized magnitude estimation protocol. Pain sensitivity in participants with UCPPS was compared with healthy controls and a mixed pain group composed of individuals with other chronic overlapping pain conditions, including fibromyalgia, chronic fatigue, and irritable bowel syndromes. Data from 6 participating MAPP testing sites were pooled for analysis. Participants with UCPPS (n = 153) exhibited an intermediate pain sensitivity phenotype: they were less sensitive relative to the mixed pain group (n = 35) but significantly more sensitive than healthy controls (n = 100). Increased pain sensitivity in patients with UCPPS was associated with both higher levels of clinical pain severity and more painful body areas outside the pelvic region. Exploratory analyses in participants with UCPPS revealed that pain sensitivity increased during periods of urologic symptom flare and that less pressure pain sensitivity at baseline was associated with a greater likelihood of subsequent genitourinary pain improvement 1 year later. The finding that individuals with UCPPS demonstrate nonpelvic pain hypersensitivity that is related to clinical symptoms suggests that central nervous system mechanisms of pain amplification contribute to UCPPS.

Takafumi Hattori,1,2 Satoshi Ohga,3 Kazuhiro Shimo,3 Yuto Niwa,1 Yuji Tokiwa,1 Takako Matsubara1,3 1Faculty of Rehabilitation, Kobe Gakuin University Graduate School, Kobe, Hyogo, Japan; 2Department of Rehabilitation, Maehara Orthopedics Rehabilitation Clinic, Obu, Aichi, Japan; 3Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Hyogo, JapanCorrespondence: Takafumi Hattori, Faculty of Rehabilitation, Kobe Gakuin University Graduate School, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe, Hyogo, 651-2180, Japan, Tel/Fax +81-78-974-2461, Email hattor91@gmail.comPurpose: Knee osteoarthritis (KOA) is a degenerative disease with inflammation, becoming persistent as it progresses, resulting in reduced quality of life. Exercise is the recommended treatment for KOA; however, the extent of pain reduction with exercise is heterogeneous and the prognostic implications of baseline factors in patients undergoing exercise are still unknown. This study examined the association between the response to exercise therapy and clinical outcomes, radiologic severity, and pain sensitization, and investigated the optimal predictive value for the effectiveness of exercise.Patients and Methods: Demographics, radiologic severity, pressure pain threshold (PPT), and temporal summation of pain (TSP) at the knee, tibia, and forearm were assessed at baseline. The pain numeric rating scale (NRS) was assessed before and after 12 weeks of exercise. Patients were divided into responder/non-responder groups according to recommended criteria: responder, ≥ 30% reduction in pain; non-responder, < 30% reduction in pain, and each variable was compared between the groups. The area under the curve (AUC) and cutoff points were determined by receiver operating characteristic curve analysis.Results: Sixty-five patients were categorized as responders and 26 as non-responders. In the non-responder group, baseline NRS (P< 0.01), pain duration (P< 0.01), and TSP at the knee (P< 0.001) and tibia (P< 0.05) were significantly higher, and PPT at the knee (P< 0.001), tibia (P< 0.001), and forearm (P< 0.001) were significantly lower, than those in the responder group; however, no significant differences between groups were found in other demographics and radiologic severity. The variables that showed moderate or better predictive ability (AUC≥ 0.7) were PPT at the knee (cutoff points: 241.5 kPa), tibia (307.5 kPa), forearm (318.5 kPa), and TSP at the knee (15.5 mm).Conclusion: Our findings suggest that pain sensitization is associated with the response to exercise therapy. Furthermore, we provide clinically predictive values for PPT and TSP in predicting the outcome to exercise in KOA.Keywords: pressure pain threshold, temporal summation of pain, cutoff point, prognostic prediction

Yuto Niwa,1 Kazuhiro Shimo,2 Satoshi Ohga,2 Yuji Tokiwa,1 Takafumi Hattori,1 Takako Matsubara1,2 1Faculty of Rehabilitation, Kobe Gakuin University Graduate School, Kobe, Japan; 2Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, JapanCorrespondence: Yuto Niwa, Faculty of Rehabilitation, Kobe Gakuin University Graduate School, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe, Hyogo, 651-2180, Japan, Tel +81-90-6587-2828, Email rm9wol04@s.kobegakuin.ac.jpPurpose: Exercise-induced hypoalgesia (EIH) is a reduction in pain sensitivity that occurs following a single bout of exercise. However, little research has compared the EIH effects of exercise at different intensities, including low intensity, in the same participant. It is unclear as to which exercise intensities demonstrate EIH more effectively. The aim of this study was to examine and compare the effect of different intensities of exercise on pain sensitivity in the same participant.Methods: We included 73 healthy young adult volunteers (35 female and 38 male) in this experimental cross-over study. Each participant completed four experimental sessions of 30 min, consisting of aerobic exercise at 30% heart rate reserve (HRR), aerobic exercise at 50% HRR, aerobic exercise at 70% HRR, and quiet rest. EIH was assessed using the pressure pain threshold (PPT) and temporal summation of pain (TSP) in the quadriceps, biceps, and trapezius.Results: Low- and moderate-intensity exercise increased the multisegmental PPT and reduced TSP (all P < 0.05). High-intensity exercise increased the multisegmental PPT (all P < 0.05), but decreased TSP in only the quadriceps and biceps (P < 0.05), not the trapezius (P = 0.13). We found no difference in relative PPT and TSP changes between exercise intensities (P > 0.05) except for relative PPT change at the quadriceps (P < 0.05).Conclusion: Our results show that not only moderate- and high-intensity exercise, but also low-intensity exercise can produce a hypoalgesic response.Keywords: exercise intensity, exercise-induced hypoalgesia, aerobic exercise, pressure pain threshold, temporal summation of pain

(1) Background: Hemophilia is characterized by recurrent hemarthrosis leading to degenerative arthropathy. The aim was to evaluate the differences in muscle strength and activity and the pressure pain threshold between patients with knee arthropathy and their healthy peers; (2) Methods: A case-control study in which 23 adult patients with knee arthropathy and 24 healthy peers matched in terms of characteristics were recruited. The study variables were quadriceps muscle strength, muscle activation and the pressure pain threshold; (3) Results: There were significant differences between the two groups in quadriceps strength on the dominant (CI95%: 64.69, 129.2) and non-dominant (CI95%: 29.95, 93.55) sides and in the pressure pain threshold on the dominant (CI95%: 3.30, 43.54) and non-dominant (CI95%: 3.09, 45.25) sides. There were differences in neuromuscular fatigue on the non-dominant side in the vastus medialis (CI95%: 8.72, 21.51), vastus lateralis (CI95%: 4.84, 21.66) and rectus femoris (CI95%: 6.48, 24.95) muscles; (4) Conclusions: Muscle strength and the pressure pain threshold are lower in patients with hemophilia. Quadriceps muscle activation in patients with hemophilic knee arthropathy does not in any way differ from activation in healthy subjects. However, muscle fatigue is greater in patients with knee arthropathy. Strength training in patients with hemophilia should focus on the activation of the vastus medialis and lateralis muscles. [ABSTRACT FROM AUTHOR]

Purpose: To our knowledge, no study has demonstrated the effects of Kinesio Taping (KT) tension on pressure-pain threshold and tolerance. The aim of the study was to investigate the effect of KT tension tensions on pressure pain threshold and tolerance. Material and Methods: A double-blind, randomized controlled study was conducted with 90 healthy male subjects with an average age of 21.04 ± 2.0 years. The subjects were randomized into four groups: 0% tension (n=23), 50% tension (n= 24), 75% tension (n=22) and 100% tension groups (n=21). The KT was applied from distal to proximal, exposing the lateral epicondyle region on the dominant side. Pressure pain threshold and pain tolerance were measured using digital algometer over the lateral epicondyle. Measurements were carried out, before, immediate after and 30 minutes after KT. Results: There was no statistically significant difference between the groups in terms of PP threshold, pain tolerance and intensity (p>0.05). There was a significant in-group difference only in the 100% Tension Group in terms of PP threshold (p<0.05). On the other hand, a significant difference was observed in the 0% tension and 50% tension groups on the pain severity measurements (p<0.05). Conclusion: The results demonstrated that the KT at different tensions did not affect the pressure pain threshold or tolerance. The outcomes also considered the efficacy of low- and high-tension KT on pain tolerance and severity, respectively. A further study should investigate the pain threshold and tolerance in clinical cases with a long-term follow-up. [ABSTRACT FROM AUTHOR]

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Pain-inducing massage produces comparable changes in pain sensitivity as a cold pressor task, suggesting shared neurophysiological mechanisms of conditioned pain modulation. Manual therapy and conditioned pain modulation are influenced by positive and negative expectations. Therefore, the purpose of this study was to examine the effects of positive and negative expectations on pain-free and pain-inducing massage. 56 healthy participants were randomly assigned to receive a positive or negative expectation instructional set followed by a pain-inducing or a pain-free massage. Pressure pain threshold (PPT) was measured followed by each interval of massage. A repeated measures ANCOVA controlling for post-randomization differences in sex tested for massage x expectation set x PPT interaction effects, as well as two-way interaction effects. A significant three-way interaction effect (p = 0.04) and time x expectation interaction effect was observed for individuals receiving pain inducing massage (p = 0.02). Individuals who received the positive expectation instructional set demonstrated significantly higher PPT at minutes 3 and 4 of massage compared to individuals who received the negative expectation instructional set. Expectations impact pain sensitivity changes produced during massage. Clinicians planning to provide pain-inducing massage should consider the role of expectations in modulating pain sensitivity changes. [ABSTRACT FROM AUTHOR]

Background: Apart from the positive effect of lumbar traction on structural changes within the spine in patients with low back pain, it is likely that therapeutic effects are correlated with pain biomarkers in the blood. Among them, systemic metabolic factors related to obesity may play an important role. This is the first study designed to examine the effectiveness of traction therapy in two experimental groups with considerably different BMI and to assess relationships between blood biomarkers and low back pain intensity. Methods: In the prospective clinical trial, women suffering from chronic low back pain were allocated into the normal-weight or obesity groups. Patients in both groups underwent twenty sessions of lumbar traction therapy (30 min a day, continuous mode with a force level of 25–30% of body weight). Before and after therapy subjective assessments of pain (VAS and PPT) were performed, and serum concentrations of aggrecan chondroitin sulfate 846 epitope (CS-846), neuropeptide Y, leptin, adipsin and growth and differentiation factor 15 (GDF-15) were determined. The data were statistically evaluated for 28 women. Results: After therapy, the maximal low back pain decreased in both groups, GDF-15 concentration was reduced in the normal-weight group and increased in the obesity group, and CS-846 concentration decreased in the obesity group. The sensation of PPT in the lumbar spine and mean concentrations of neuropeptide Y, leptin and adipsin did not change in both groups. However, the relationships of GDF-15, leptin, and adipsin concentrations with the perception of pain were revealed. Conclusion: Distinct differences between the normal-weight and obesity groups pointed on the role of excessive adipose tissue in aggravating the inflammatory processes and in the development of low back pain. Adipsin, CS-846 and GDF-15 aspire to be the low back pain biomarkers in women with obesity, but there is a need for further research to answer whether they might be considered reliable biomarkers for the prognosis and monitoring of chronic low back treatment. Trial registration: NCT04507074, registered prospectively on July 6, 2020. [ABSTRACT FROM AUTHOR]

Objective Spinal manual therapy (SMT) is often used to treat patients with spinal disorders; however, the underlying mechanisms of SMT are not fully understood. This systematic review and meta-analysis investigates the effect of SMT compared with sham treatment or no intervention on local or remote (segmental or non-segmental) pressure pain thresholds (PPTs) in patients with chronic musculoskeletal conditions and people who are pain free. Methods A systematic search was conducted in the PubMed, Cochrane Library, Web of Science, and CINAHL databases. Randomized controlled trials investigating the effect of SMT on PPTs in patients with chronic musculoskeletal conditions and in people who were pain free were included. Quality assessment and evidence synthesis were performed according to Cochrane Handbook recommendations. A meta-analysis was performed using standardized mean difference and 95% CIs. Results Twenty-two reports were included in the present review. There were no significant results for an immediate effect of SMT on local (low certainty of evidence), remote (segmental) (low certainty of evidence), and remote (non-segmental) (low certainty of evidence) PPTs in patients with chronic pain as well as on local (moderate certainty of evidence) and remote (segmental) (low certainty of evidence) PPTs in people who were pain free. A small but significant effect (standardized mean difference = 0.26; 95% CI = 0.01 to 0.51; low certainty of evidence) was observed on remote (non-segmental) PPTs in people who were pain free, which was not considered a meaningful effect size. Conclusion No immediate, consistent, or meaningful hypoalgetic effect of SMT was shown on PPTs on various body areas. Involvement of spinal or supraspinal underlying mechanisms were, therefore, not confirmed via PPTs but should still be investigated using methods designed to assess central nervous pain processing. Impact No consistent and meaningful hypoalgesic effects of spinal manual therapy were demonstrated on PPTs in participants who were pain free and in patients with chronic musculoskeletal disorders. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to investigate central sensitization and associated factors in knee osteoarthritis (OA) patients and compare them with rheumatoid arthritis (RA) patients and healthy controls. Patients and methods: This cross-sectional study was conducted with 125 participants (7 males, 118 females; mean age: 57.2±8.2 years; range, 45 to 75 years) between January 2017 and December 2018. Sixty-two patients with symptomatic knee OA, 32 RA patients with knee pain, and 31 healthy controls constituted the participants. Central sensitization was investigated with the Central Sensitization Inventory (CSI) and pressure pain threshold (PPT) measurements. Pain, functional status, and psychosocial features were assessed with self-reported questionnaires. Results: The OA and RA groups had significantly lower PPT values at local, peripheral, and remote regions compared to the healthy controls. Pressure hyperalgesia was shown at the knee with a 43.5% prevalence, 27.4% at the leg, and 8.1% at the forearm of OA patients. Pressure hyperalgesia was present at the knee, leg, and forearm in 37.5%, 25%, and 9.4% of RA patients, respectively. Pressure pain threshold values, CSI scores, frequency of pressure hyperalgesia, and frequency of central sensitization according to the CSI were not statistically different between the OA and RA groups. Psychosocial features and structural damage were not correlated with PPT values in the OA group. Conclusion: The severity of chronic pain and functional status may be the clinical clues to recognizing patients with central sensitization since local joint damage does not play a direct role in the etiopathogenesis of central sensitization in OA patients and severe pain persisting in the chronic process is associated with central sensitization regardless of the pathogenesis. [ABSTRACT FROM AUTHOR]

Abstract Background Changes in pain sensitivity are a commonly suggested mechanism for the clinical effect of spinal manipulative therapy (SMT). Most research has examined pressure pain thresholds (PPT) and has primarily been conducted in controlled experimental setups and on asymptomatic populations. Many important factors are likely to differ between research and clinical settings, which may affect PPT changes following SMT. Therefore, we planned to investigate PPT before and after clinical chiropractic care and investigate relationships with various potentially clinically-relevant factors. Methods We recruited participants from four Danish chiropractic clinics between May and August 2021. A total of 129 participants (72% of the invited) were included. We measured PPT at eight pre-determined test sites (six spinal and two extra-spinal) immediately before (pre-session) and immediately after (post-session) the chiropractic consultation. We used regression analyses to investigate PPT changes, including the following factors: (i) vertebral distance to the nearest SMT site, (ii) rapid clinical response, (iii) baseline PPT, (iv) number of SMTs performed, (v) at the region of clinical pain compared to other regions, and (vi) if other non-SMT treatment was provided. We also performed topographic mapping of pre-session PPTs. Results After the consultation, there was a non-significant mean increase in PPT of 0.14 kg (95% CIs = − 0.01 to 0.29 kg). No significant associations were found with the distance between the PPT test site and nearest SMT site, the clinical response of participants to treatment, the pre-session PPT, the total number of SMTs performed, or the region/s of clinical pain. A small increase was observed if myofascial treatment was also provided. Topographic mapping found greater pre-session PPTs in a caudal direction, not affected by the region/s of clinical pain. Conclusions This study of real-world chiropractic patients failed to demonstrate a substantial local or generalized increase in PPT following a clinical encounter that included SMT. This runs counter to prior laboratory research and questions the generalizability of highly experimental setups investigating the effect of SMT on PPT to clinical practice.

Simple Summary: Physical or sports activities are believed to reduce pain sensitivity following activity sessions. Several studies have explored the effect of different exercise intensities of the activity sessions on pain sensitivity and most studies reported that pain sensitivity is reduced after the sessions. Above all, this phenomenon is observed when a rather high intensity was used. However, almost no studies have explored the effect of longer duration exercise sessions on this phenomenon. Therefore, this study aimed to explore pain sensitivity following three differently long, i.e., 30, 45, and 60 min, exercise sessions, which were conducted using the same sub-maximal intensity. The results show that none of these sessions led to differences in pain sensitivity. The results were not as expected but might lead to the assumption that the intensity might be more important for inducing a reduced pain sensitivity than the duration of the session. Acute physical activity is assumed to lead to exercise-induced hypoalgesia (EIH). Yet, little research has been conducted dealing with the influence of exercise duration on EIH. The aim of this study was to investigate the effects of three different exercise durations using the same intensity compared to a control session on EIH. A total of 36 participants conducted three different exercise sessions on a bicycle ergometer for 30, 45, and 60 min, respectively, in addition to a passive control session. The intensity was set to 75% of the individual's VO2max. Pre and post exercise, pain sensitivity was measured employing pressure pain thresholds (PPT) at the elbow, knee, and ankle joints, as well as the sternum and forehead. In addition, the conditioned pain modulation (CPM) response was conducted pre and post exercise. The results reveal that the exercises neither led to any changes in PPT measured at any landmark nor induced any CPM response effects. These results do not confirm the hypoalgesic effects usually observed after exercise. The reasons explaining these results remain rather elusive but might be explained by the low intensities chosen leading to a milder release of pain inhibiting substances, the landmarks employed for PPT measurements, or potential non-responsiveness of participants. [ABSTRACT FROM AUTHOR]

BACKGROUND: Acupoints are considered a dynamic functional area, which can reflect the internal condition of the body. In pathological states, disease-related acupoints are believed to be activated, which is known as acupoint sensitization. OBJECTIVE: This study aimed to investigate the major manifestations of acupoint sensitization in patients with chronic low back pain (cLBP) to provide better understanding of acupoint sensitization phenomena in the context of cLBP. METHODS: This study was a matched-sample cross-sectional study 16 participants diagnosed with cLBP and 16 healthy controls matched in age, sex, and ethnicity were included. The following aspects of sensitization phenomena of targeted points were compared: pressure pain threshold (PPT), skin temperature, surface electrical conductance, receptive field, and morphological change of skin. RESULTS: PPT at points of interest were significantly lower in cLBP participants compared with healthy controls (P < 0.05); in addition, receptive field was found to be larger at left BL 23 in cLBP participants (P < 0.05). There was no statistically significant difference in skin temperature, electrical conductance, or morphology between the two groups. CONCLUSIONS: Reduced PPT at all detected points and enlarged receptive field at left BL 23 were found in cLBP participants. These two features appear key in defining acupoint sensitization in cLBP, and provide evidence for selecting and locating acupuncture points in future clinical studies. [ABSTRACT FROM AUTHOR]

Background Patellofemoral pain (PFP) is a common overuse injury among runners, affecting females at a higher rate than males. PFP can often become chronic, with evidence suggesting it may be linked to both peripheral and central sensitization of the nervous system. Sensitization of the nervous system can be identified through quantitative sensory testing (QST). Hypothesis/Purpose The primary objective of this pilot study was to quantify and compare pain sensitivity as identified through QST measures, in active female runners with and without PFP. Study Design Cohort Study Methods Twenty healthy female runners and 17 female runners with chronic PFP symptoms were enrolled. Subjects completed the Knee injury and Osteoarthritis Outcome Score for Patellofemoral Pain (KOOS-PF), University of Wisconsin Running Injury and Recovery Index (UWRI), and the Brief Pain Inventory (BPI). QST consisted of pressure pain threshold testing to three local and three distant sites to the knee, heat temporal summation, heat pain threshold, and conditioned pain modulation. Data was analyzed utilizing independent t-tests for comparison of between-group data, effect sizes for QST measures (Pearson's r), and Pearson's correlation coefficient between pressure pain threshold values at the knee and functional testing. Results The PFP group exhibited significantly lower scores on the KOOS-PF (p<0.001), BPI Pain Severity and Interference Scores (p<0.001), and UWRI (p<0.001). Primary hyperalgesia, identified through decreased pressure pain threshold at the knee, was detected in the PFP group at the central patella (p<0.001), lateral patellar retinaculum (p=0.003), and patellar tendon (p=0.006). Secondary hyperalgesia, a sign of central sensitization, was observed via differences in pressure pain threshold testing for the PFP group at the uninvolved knee (p=0.012 to p=0.042), involved extremity remote sites (p=0.001 to p=0.006), and uninvolved extremity remote sites (p=0.013 to p=0.021). Conclusion Compared to healthy controls, female runners with chronic PFP symptoms exhibit signs of both peripheral sensitization. Despite actively participating in running, nervous system sensitization may contribute to continued pain in these individuals. For female runners with chronic PFP, physical therapy management may need to include interventions which address signs of central and peripheral sensitization. Level of Evidence Level 3 [ABSTRACT FROM AUTHOR]

Background: Experienced assessors show good intra-rater reproducibility (withinsession and between-session agreement and reliability) when using an algometer to determine pressure pain thresholds (PPT). However, it is unknown whether novice assessors perform equally well. This study aimed to determine within and between-session agreement and reliability of PPT measurements performed by novice assessors and explored whether these parameters differed per assessor and algometer type. Methods: Ten novice assessors measured PPTs over four test locations (tibialis anterior muscle, rectus femoris muscle, extensor carpi radialis brevis muscle and paraspinal muscles C5-C6) in 178 healthy participants, using either a Somedic Type II digital algometer (10 raters; 88 participants) or a Wagner Force Ten FDX 25 digital algometer (nine raters; 90 participants). Prior to the experiment, the novice assessors practiced PPTs for 3 h per algometer. Each assessor measured a different subsample of ~9 participants. For both the individual assessor and for all assessors combined (i.e., the group representing novice assessors), the standard error of measurement (SEM) and coefficient of variation (CV) were calculated to reflect within and between-session agreement. Reliability was assessed using intraclass correlation coefficients (ICC1,1). Results: Within-session agreement expressed as SEM ranged from 42 to 74 kPa, depending on the test location and device. Between-session agreement, expressed as SEM, ranged from 36 to 76 kPa and the CV ranged from 9-16% per body location. Individual assessors differed from the mean group results, ranging from -55 to +32 kPa or from -9.5 to +6.6 percentage points. Reliability was good to excellent (ICC1,1: 0.87 to 0.95). Results were similar for both types of algometers. Conclusions: Following 3 h of algometer practice, there were slight differences between assessors, but reproducibility in determining PPTs was overall good. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to investigate the effects of photobiomodulation (PBM), low-intensity stretching, and their combination on delayed-onset muscle soreness (DOMS) in the untrained population. The relationships between DOMS and muscle function and functional performance were also tested. Methods: Fifty-four participants were randomized into four groups. Eccentric exercise was used to induce DOMS. Each group received either no treatment, PBM, stretching or PBM combined with stretching at 24, 48, and 72h postexercise. Pressure pain threshold (PPT), numerical rating scale (NRS), single-leg forward jump (SLFJ), and maximum isometric voluntary contraction (MIVC) were measured at baseline, 24, 48, 72, and 96 h after eccentric exercise. Between-group differences were tested using two-way repeated measures analysis of variance and the relationships between DOMS and MIVC, and SLFJ were examined using Pearson's correlation analysis. Results: The PPT at the vastus medialis and vastus lateral in the PBM combined with stretching group was significantly lower than that in control group at 72 h (p = 0.045) and 48 h (p = 0.037) postexercise. No significant between-group difference in PPT was found for the rest occasions. There was no significant between- group difference in NRS, MVIC, and SLFJ on any occasion (p ≥ 0.052). DOMS was not correlated with MIVC and SLFJ (p ≥ 0.09). Conclusions: PBM or low-intensity stretching did not affect DOMS and functional performance in untrained individuals. The combination of PBM and low-intensity stretching increased pain sensitivity and did not relieve soreness. The DOMS was not associated with either muscle function or functional performance. [ABSTRACT FROM AUTHOR]

We aimed to evaluate the hypoalgesic effect of an elbow flexion low-load resistance exercise with blood flow restriction (LLRE–BFR) when compared to high-load resistance exercise (HLRE) with sham-BFR in healthy individuals. Forty healthy young adults (17 women), with a mean age ± SD: 26.6 ± 6.8 years, and mean body mass index ± SD: 23.6 ± 2.7 were randomly assigned to either an LLRE–BFR (30% 1 repetition maximum, RM) or an HLRE with sham-BFR group (70% of 1 RM). Blood pressure and pressure pain thresholds (PPTs) were measured pre- and post-exercise intervention. The rating of perceived exertion (RPE) was recorded after each set. There were non-significant between-group changes in PPT at the dominant biceps (−0.61, 95%CI: −1.92 to 0.68) with statistically significant reductions between pre- and post-exercise in LLRE–BFR (effect size, d = 0.88) and HLRE-BFR (effect size, d = 0.52). No within- or between-group differences were recorded in PPT at non-exercising sites of measurement. No mediating effects of changes in blood pressure or RPE on the changes in pressure pain threshold were observed. LLRE–BFR produced a similar hypoalgesic effect locally compared to HLRE and can be used as an alternative intervention to decrease pain sensitivity when HLRE is contraindicated or should be avoided. [ABSTRACT FROM AUTHOR]

Aim: Identify values that could predict the presence of increased pressure-pain sensitivity independent of the migraine cycle through a single assessment., Methods: This was a secondary analysis of a previous study in which 198 episodic and chronic migraine patients were assessed during all phases of the migraine cycle. Pressure pain threshold (PPT) was assessed over the temporalis, cervical spine, hand, and leg. Migraine patients were divided into two sub-groups: patients with increased pressure-pain sensitivity (IPS) and with No IPS (No-IPS). A Chi-squared Automatic Interaction Detection decision tree analysis was used to identify predictors to be included in the IPS or NoIPS group. To assess the internal validity of the model, a tenfold cross-validation was applied., Results: 161 (81%) patients were included in the IPS group, while 37 (19%) in the NoIPS group. Migraine patients with: (1) Temporalis PPT ≤ 130 kPa; (2) Temporalis PPT > 130 kPa and ≤ 197.5 kPa and hand PPT ≤ 347.33 kPa; (3) Temporalis PPT > 197.5 kPa and hand PPT ≤ 315 kPa; were correctly included in the IPS group with a sensitivity of 96%, a specificity of 81%, a positive predictive value of 96%, and a negative predictive value of 81%. The accuracy of the model and the cross-validation analysis were respectively 93% and 92%., Conclusion: The high internal validity suggests that our model could precisely predict the presence of IPS independently by the phase in which the assessment occurred. Trigeminal and hand PPT cut-off values could be used to identify patients with IPS., (© 2025 The Author(s). European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation ‐ EFIC ®.)

Abstract Background Pain sensitisation plays a major role in musculoskeletal pain. However, effective treatments are limited, and although there is growing evidence that exercise may improve pain sensitisation, the amount and type of exercise remains unclear. This systematic review examines the evidence for an effect of aerobic exercise on pain sensitisation in musculoskeletal conditions. Methods Systematic searches of six electronic databases were conducted. Studies were included if they examined the relationship between aerobic physical activity and pain sensitisation in individuals with chronic musculoskeletal pain, but excluding specific patient subgroups such as fibromyalgia. Risk of bias was assessed using Cochrane methods and a qualitative analysis was conducted. Results Eleven studies (seven repeated measures studies and four clinical trials) of 590 participants were included. Eight studies had low to moderate risk of bias. All 11 studies found that aerobic exercise increased pressure pain thresholds or decreased pain ratings in those with musculoskeletal pain [median (minimum, maximum) improvement in pain sensitisation: 10.6% (2.2%, 24.1%)]. In these studies, the aerobic exercise involved walking or cycling, performed at a submaximal intensity but with incremental increases, for a 4-60 min duration. Improvement in pain sensitisation occurred after one session in the observational studies and after 2-12 weeks in the clinical trials. Conclusions These findings provide evidence that aerobic exercise reduces pain sensitisation in individuals with musculoskeletal pain. Further work is needed to determine whether this translates to improved patient outcomes, including reduced disability and greater quality of life.

Objectives: An acute bout of exercise typically leads to short term exercise induced hypoalgesia (EIH), but this response is more variable in many chronic pain populations, including knee osteoarthritis (OA) and fibromyalgia (FM). There is evidence of autonomic nervous system (ANS) dysfunction in some chronic pain populations that may contribute to impaired EIH, but this has not been investigated in people with knee OA. The aim of this study was to assess the acute effects of isometric exercise on the nociceptive and autonomic nervous systems in people with knee OA and FM, compared to pain-free controls. Methods: A cross-sectional study was undertaken with 14 people with knee OA, 13 people with FM, and 15 pain free controls. Across two experimental sessions, baseline recordings and the response of the nociceptive and autonomic nervous systems to a 5-min submaximal isometric contraction of the quadriceps muscle was assessed. The nociceptive system was assessed using pressure pain thresholds at the knee and forearm. The ANS was assessed using high frequency heart rate variability, cardiac pre-ejection period, and electrodermal activity. Outcome measures were obtained before and during (ANS) or immediately after (nociceptive) the acute bout of exercise. Results: Submaximal isometric exercise led to EIH in the control group. EIH was absent in both chronic pain groups. Both chronic pain groups showed lower vagal activity at rest. Furthermore, people with knee OA demonstrated reduced vagal withdrawal in response to acute isometric exercise compared to controls. Sympathetic reactivity was similar across groups. Discussion: The findings of reduced tonic vagal activity and reduced autonomic modulation in response to isometric exercise raise the potential of a blunted ability to adapt to acute exercise stress and modulate nociception in people with knee OA. The impairment of EIH in knee OA may, in part, be due to ANS dysfunction.

Inertial sensors (IMUs) have been recently widely used in exercise and rehabilitation science as they can provide reliable quantitative measures of range of motion (RoM). Moreover, the pressure pain threshold (PPT) evaluation provides an objective measure of pain sensation in different body areas. The aim of this study was to evaluate the efficacy of physiotherapy treatment in people with adhesive capsulitis in terms of RoM and pain improvement measured by IMUs and the PPT. A combined prospective cohort/cross-sectional study was conducted. Nineteen individuals with adhesive capsulitis (10/19 females, 54 ± 8 years) and nineteen healthy controls (10/19 females, 51 ± 6 years) were evaluated for active glenohumeral joint RoM and PPT on shoulder body areas. Then, individuals with adhesive capsulitis were invited to 20 sessions of a physiotherapy protocol, and the assessments were repeated within 1 week from the last session. The range of motion in the flexion (p = 0.001) and abduction (p < 0.001) of the shoulder increased significantly after the physiotherapy protocol. Similarly, the PPT was found to increase significantly in all the assessed shoulder body areas, leading to no significant differences compared to the healthy controls. IMU and PPT assessments could be used to evaluate the efficacy of physical therapy in people with adhesive capsulitis.

Objective: This systematic review aimed to investigate the efficacy of photobiomodulation therapy (PBMT) on pain and pressure pain threshold (PPT) in patients with myofascial pain syndrome (MPS) of the upper trapezius muscle. Materials and methods: A total of 17 studies (944 patients) were included; data regarding participants, intervention parameters, outcome measures, time of measurement, and follow-up were extracted. Evaluation of the methodological quality was performed by Physiotherapy Evidence Database (PEDro) scale. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was used to assess the quality of evidence. A meta-analysis was performed on 16 studies, and standardized mean difference (SMD), corresponding 95% confidence interval (CI), and overall effect size (ES) were calculated. Results: Meta-analysis using a random-effect model was performed to evaluate the effects of PBMT alone or PBMT plus exercise (EX) compared with placebo, medical treatment, physical therapy (PT) modality, manual therapy, or complementary PT. Assessment according to the PEDro scale revealed 12 high-quality, 3 fairquality, and 2 low-quality studies. According to the GRADE system, studies exhibited low to medium quality of evidence, with medium ES [SMD -0.54 (95% CI -1.05 to -0.02)] for studies using PBMT alone and large ES [SMD -0.80 (95% CI -1.35 to -0.26)] for PBMT+EX. Conclusions: The present systemic review revealed that PBMT is an effective PT modality for reducing pain and increasing PPT in patients with MPS of the upper trapezius. PBMT, when combined with EX, had more significant effects in reducing pain and increasing PPT compared with controls. The low-quality studies with low to moderate quality of evidence limit the confidence in the effect estimate and recommend further highquality studies for standardization of treatment protocols and irradiation parameters. [ABSTRACT FROM AUTHOR]

The stretching intervention of the current study was applied from several principles and the latest updated method of slowed and synchronized patterns between self-stretching with mindful breathing (MB) and eyes closed period before and after the self-stretching was performed at least four times repeatedly within 150 s per each pose. To investigate effects of self-stretching in five poses with and without MB on pain and cervical range of motion (CROM). The study was a randomized clinical trial with a blinded assessor. The participants were 30 females per group, aged 30–59 years with myofascial pain syndrome (MPS). The participants were evaluated via the pressure pain threshold (PPT) at the upper trapezius muscles and the CROM. Both groups showed that the PPT at upper trapezius muscles significantly increased after performing the stretching (p < 0.001). The ROM in the MB group significantly increased in extension, left and right lateral flexion, and left rotation (p < 0.05). Self-stretching with mindful breathing was designed to allow for effects within the shortest time in patients with myofascial pain syndrome. Since this treatment is a non-pharmacological intervention and was considered as part of active self-care, we suggest that this therapy could be used as alternative therapy for patients with MPS. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to evaluate the efficacy and safety of thiocolchicoside (TCC) ointment treatment compared to placebo in patients with chronic mechanical low back pain (LBP) accompanied by acute muscle spasms. Patients and methods: A total of 292 adult patients (106 males, 186 females; mean age: 38.5±11.2 years; range, 18 to 64 years) were randomized to TCC group (n=147) and placebo group (n=145) in 12 centers between March 2020 and March 2021. Eight patients from each group were excluded from the analysis. The primary endpoint was pressure pain threshold (PPT) on Day 3, which was measured using a pressure algometer. Secondary endpoints were PPT on Day 7, patient, and physician Visual Analog Scales-pain (VAS-pain) on Days 3 and 7, and safety. Results: The PPT values on Day 3 was not significantly different between the treatment groups (p=0.701). Similarly, TCC and placebo group had similar VAS-pain scores over trial period (p=0.577 or higher for comparisons). Significantly higher PPT values and lower VAS-pain scores on Days 3 and 7 were observed in both groups (p<0.001 for all). In patients with a PPT value of =3.87, TCC arm had higher PPT on Day 3 compared to placebo (p=0.029). Three patients (two in the TCC arm and one in the placebo arm) discontinued the trial due to an adverse event. Conclusion: Topical TCC can be an appropriate option in a subset of patients with mild chronic LBP accompanied by muscle spasms. In a subset of patients with milder pain intensity, topical TCC may improve pain earlier. The results of this trial are compatible with the treatment approaches used in daily practice. [ABSTRACT FROM AUTHOR]

Objective: The aim of our study is to evaluate the sleep quality, life satisfaction and general psychological status of healthy individuals and to examine whether the pressure pain threshold changes according to these factors. Material and Method Healthy young adults aged 18-25 years were included in the study. The PPT was measured using the algometer over the deltoid, ulna, hypotenar bump, thumb of the hand, tibia and quadriceps femoris muscle. Pittsburgh Sleep Quality Index (PUKI), Satisfaction with Life Scale (SWLS) and General Health Questionnaire (GHQ) were used to evaluate the sleep, quality of life, general health and psychological status of the participants. Results: A total of 205 subjects [102 female (49.8%) and 103 male (50.2%)] with a mean age of 20.4±1.4 years participated in the study. When the relationship between pressure pain threshold-general body average (PPT-GBA) and the parameters of SWLS, GHQ and PSQI was examined, PPT-GBA was found to be; It was found that there was a positive low correlation with SWLS, negative correlation with GHQ and negative correlation with PSQI. Conclusion: There are many psychosocial factors that affect the pressure pain threshold. The fact that factors such as life satisfaction, psychological health status and sleep quality are good ensure that the pressure pain threshold is perceived at high values. [ABSTRACT FROM AUTHOR]

Abstract Background Dry needling (DN) is increasingly used for treating myofascial trigger points (MTrPs) and has shown significant effects on pain and function. This study aimed to assess feasibility of conducting a randomized sham-controlled trial and to collect preliminary data on the effects of infraspinatus DN on corticospinal excitability and mechanical pain sensitivity. Method This randomized feasibility study included adults with chronic non-traumatic shoulder pain and a infraspinatus MTrP. Participants were randomized to receive real DN or sham DN in the infraspinatus MTrP. Feasibility outcomes included data pertaining to recruitment, retention of participants, completeness and safety of assessment procedures. Neurophysiological and psychophysical outcomes included corticospinal excitability and mechanical pain sensitivity measured by active motor threshold (aMT) and pressure pain threshold (PPT), respectively. They were assessed at baseline, immediately after and 24 h post-intervention. Results Twenty-one participants were recruited over a 6-month period. Nineteen participants completed the treatment and follow-up assessment. Motor evoked potential responses were discernible in all but 1 participant. Only 1 minor adverse event related to transcranial magnetic stimulation (mild headache) affected the measurements. No DN adverse effects were recorded in both groups. An overall completeness rate of 81% was reached, with 70% completeness in the DN group and 91% in the sham group. Data analysis revealed that real DN increased corticospinal excitability (reduced aMT) 24 h post-intervention (Mdn = − 5.96% MSO, IQR = 5.17, p = 0.04) and that sham DN triggered similar responses immediately after the intervention (Mdn = − 1.93% MSO, IQR = 1.11, p = 0.03). Increased mechanical pain sensitivity (reduced PPT) was significant only in the sham group, both immediately (Mdn = − 0.44 kg/cm2, IQR = 0.49, p = 0.01) and 24 h post-intervention (Mdn = − 0.52 kg/cm2, IQR = 1.02, p = 0.02). Changes in corticospinal excitability was positively correlated with changes in mechanical pain sensitivity in the DN group, both immediately (r = 0.77, p = 0.02) and 24 h post-intervention (r = 0.75, p = 0.05). Conclusion The present study demonstrates the feasibility of quantifying the neurophysiological and psychophysical effects of DN, and provides recommendations and guidelines for future studies. Moreover, it provides preliminary evidence that DN may increase corticospinal excitability of the infraspinatus muscle in patients with chronic shoulder pain and that the relationship of neurophysiological and psychophysical effects is promising to better understand its mechanisms of action. Trial registration NCT04316793 ; retrospectively registered November 3, 2020.

Objective To elucidate the efficacy and safety of MRgFUS in the treatment for refractory pain derived from medial knee OA. Methods Twenty patients with medial knee OA eligible for total knee arthroplasty were included in this prospective, non-controlled study (UMIN000010193). MRgFUS treatment was provided at the site of most severe tenderness around the medial femorotibial joint of each patient under real-time monitoring of temperature. The goal temperature of the targeted bone surface was 55 °C. Numerical rating scale (NRS) worst pain scores, Western Ontario and McMaster Universities osteoarthritis index (WOMAC) scores, EuroQol 5 dimensions index (EQ-5D) scores and pressure pain threshold (PPT) were evaluated before treatment (baseline) and at 1 week and 1, 3, 6, and 12 months post-treatment, respectively. Complications and adverse events were also assessed clinically and radiographically. Results Treatment response (a 50% or greater decrease in NRS score) was seen in 14 patients (14/19, 73.7%) at 12 months post-treatment. Mean NRS score rapidly decreased at 1 month after treatment and continued to decline through the following 12 months. At final follow-up, mean NRS score was 3.2 ± 1.9, significantly lower than at baseline (p = 0.0013). Mean WOMAC and EQ-5D scores also improved significantly from 1 month after treatment. Fifteen patients showed significant sustained increases in PPTs at the sites of most severe tenderness. No serious adverse events were observed during and after treatment. Conclusions MRgFUS treatments were effective not only for managing refractory pain, but also for improving physical functions without adverse events in elderly patients with medial knee OA.

Masashi Izumi,1 Yohei Harada,2,3 Yukihiro Kajita,2 Yoshitaka Muramatsu,2,4 Toru Morimoto,1 Yutaka Morisawa,5 Yusuke Iwahori,2,6 Masahiko Ikeuchi1 1Department of Orthopaedic Surgery, Kochi Medical School, Kochi University, Nankoku-City, Japan; 2Department of Orthopaedic Surgery, Aichi Medical University, Nagakute, Japan; 3Department of Orthopaedic Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan; 4Department of Orthopaedic Surgery, Saiseikai Futsukaichi Hospital, Futsukaichi, Japan; 5Department of Orthopaedic Surgery, Aki General Hospital, Aki, Japan; 6Department of Orthopaedic Surgery, Sports Medicine and Joint Center, Asahi Hospital, Kasugai, JapanCorrespondence: Masashi IzumiDepartment of Orthopaedic Surgery, Kochi Medical School, Kochi University, 185-1 Kohasu, Oko-cho, Nankoku-City, Kochi Pref, 783-8505, JapanTel +81 88-880-2386Fax +81 88-880-2388Email izumim@kochi-u.ac.jpPurpose: Degenerative long head of biceps tendon (LHBT) has been recognized as a notable pain source in patients with rotator cuff tear (RCT). Tenotomy or tenodesis of LHBT is frequently indicated together with arthroscopic rotator cuff repair (ARCR) aiming for complete pain relief; however, it has not been fully investigated whether resected LHBT is really a source of pain. The purpose of this study was to investigate expression levels of pain-associated mediators in LHBT and its association with preoperative pain profiles.Methods: Twenty-seven RCT patients who underwent ARCR with LHBT resection were included. Each LHBT was resected due to its abnormal arthroscopic findings including tenosynovitis, hypertrophy, and partial tear. Worst macroscopic lesion of the LHBT was obtained, and expression levels of substance P (SP) and nerve growth factor (NGF) were evaluated using enzyme-linked immunosorbent assay (ELISA). Ten healthy knee flexor tendons were analyzed as non-degenerative samples. Preoperatively, subjective shoulder pain VAS and pain duration were investigated. Conventional LHBT pain provocation tests (Speed, Yergason, O’Brien) were performed. Pressure pain threshold (PPT) of bilateral LHBT on the groove was recorded.Results: Levels of SP and NGF expression were significantly higher compared with non-degenerative tendons (P< 0.01). Shoulder pain VAS and pain duration were not directly associated with SP and NGF expression level. Patients with positive O’Brien test expressed greater SP than negative patients (P=0.001). Significant negative correlation between the PPT ratio (ipsilateral/contralateral) and SP expression level was observed (r=− 0.453, P=0.034).Conclusion: Greater expression of SP and NGF in degenerative LHBT supported our hypothesis that it would be a pain source in RCT patients. SP was likely to be expressed highly in patients with localized pressure pain hypersensitivity and positive O’Brien test (ie, altered mechanistic pain profile of LHBT), which may help when considering simultaneous LHBT resection during ARCR.Clinical Registration: UMIN000023943.Keywords: long head of biceps tendon, pain, tendinopathy, substance P, nerve growth factor, pressure pain threshold

Background : Temporomandibular disorders (TMDs) are treated by different modalities including splints, physiotherapy, and acupuncture. Although all of these offer evidencebased benefits to the patients, avoiding overtreatment is of paramount importance. Objectives: To assess the effectiveness of muscle pain treatment with acupuncture combined with or without occlusal splints. Methods : Recruited patients were allocated to G1 (acupuncture) and G2 (acupuncture and occlusal splint) groups and treated in four consecutive weekly sessions (P1, P2, P3, and P4). The reported pain (RP) and the pressure pain threshold (PPT) of the masseter and temporalis muscles were assessed before and after each session. Results : RP decreased after each session in G1, except at P4. In G2, the RP decreased only after the first session, and the PPT did not vary. Conclusion : The assessed treatments did not influence the PPT levels of the masseter and anterior temporalis muscles in patients with temporomandibular disorders. Our findings suggest that occlusal splints may not be mandatory along with the acupuncture treatment.

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. [ABSTRACT FROM AUTHOR]

When designing footwear products, designers and kinesiologists usually factor in plantar surface pressure, motion capture data, and subjective comfort evaluations. However, these factors alone are not sufficient to guide the design of truly comfortable shoes. Pressure pain threshold (PPT) is a parameter that establishes a connection between psychological quantities and physical quantities. The purpose of this study was to construct a high-precision PPT map of the whole foot. Overall, 20 participants were included in this study, and an electronic, mechanical algometer was used to apply constant pressure to the participants' feet. A MATLAB graphical user interface was developed to simplify the data-collecting process and generate visual representations of the data. Finally, several high-precision unisex, different sex, and dominant side PPT maps were generated. The findings revealed that the foot dorsum area and the medial foot region exhibited the lowest PPTs (indicative of high sensitivity). Notably, the foot dorsum area near the toes displayed the highest pain sensitivity (indicative of the lowest PPT), while the plantar area demonstrated comparatively lower pain sensitivity. The heel area exhibited the lowest pain sensitivity. Simultaneously, the study observed that women's feet exhibited lower pain thresholds than men's. In the future, it is imperative to delve deeper into the correlation between short-term pain sensitivity and the daily, long-term exercise state, as well as other physiological data. This exploration will contribute to a more nuanced guide for footwear comfort design. [ABSTRACT FROM AUTHOR]

In recent years, several published articles have shown that quantitative sensory testing (QST) and pressure pain threshold (PPT) are useful in the analysis of neck/shoulder and low back pain. A valid reference for normal PPT values might be helpful for the clinical diagnosis of abnormal tenderness or muscle pain. However, there have been no reliable references for PPT values of neck/shoulder and back pain because the data vary depending on the devices used, the measurement units, and the area examined. In this article, we review previously published PPT articles on neck/shoulder and low back pain, discuss the measurement properties of PPT, and summarize the current data on PPT values in patients with chronic pain and healthy volunteers. We also reveal previous issues related to PPT evaluation and discuss the future of PPT assessment for widespread use in general clinics. We outline QST and PPT measurements and what kinds of perceptions can be quantified with the PPT. Ninety-seven articles were selected in the present review, in which we focused on the normative values and abnormal values in volunteers/patients with neck/shoulder and low back pain. We conducted our search of articles using PubMed and Medline, a medical database. We used a combination of "Pressure pain threshold" and "Neck shoulder pain" or "Back pain" as search terms and searched articles from 1 January 2000 to 1 June 2022. From the data extracted, we revealed the PPT values in healthy control subjects and patients with neck/shoulder and low back pain. This database could serve as a benchmark for future research with pressure algometers for the wide use of PPT assessment in clinics. [ABSTRACT FROM AUTHOR]

Aims: (1) To determine the dose-response relationship of therapeutic ultrasound for TMD-related pain in the masseter muscle among four doses comprised of two intensities (0.4 W/cm2 and 0.8 W/cm2) and two duty cycles (50% and 100%); and (2) to determine if therapeutic ultrasound applied to the masseter muscle would elicit a segmental effect on the ipsilateral temporalis muscle. Methods: A total of 28 adult women with bilateral myalgia were randomly allocated to one of the four intervention doses. Therapeutic ultrasound was applied on each side of the masseter sequentially for 5 minutes. The following outcomes were measured before and immediately after each intervention: self-reported pain score, pressure pain thresholds for the masseter and temporalis muscles, and intraoral temperature adjacent to the treated masseter. Results: Self-reported pain scores showed neither significant main effects nor significant interaction among the intensity or duty cycle doses (all P > .05). The change in the pressure pain threshold of the masseter showed a significant interaction (P = .02) attributed to the 0.4 W/cm2 and 100% duty cycle dose. Intraoral temperature was significantly increased and associated with the duty cycle (P = .01). A significant segmental effect of the pressure pain threshold of the temporalis was found for intensity (P = .01) . Conclusion: There was an increase in the pressure pain threshold of the painful masticatory muscles and an increase in intraoral temperature adjacent to the treated area immediately after the use of ultrasound at 0.4 W/ cm2 with a 100% duty cycle. [ABSTRACT FROM AUTHOR]

Background: Neck pain is a prevalent pathological condition, and together with low back pain, it presents as the leading cause of years lived with disability worldwide in 2015 and continues to contribute substantially to the global burden of disease. Objective: This study will investigate and compare the effects of stochastic resonance therapy (SRT), whole-body vibration (WBV), and balance training (BLT) in the management of chronic nonspecific neck pain. Methods: In total, 45 participants with chronic neck pain will be randomly allocated into SRT, WBV, and BLT groups. Pain intensity, pressure pain threshold, neck disability, and cervical joint position sense will be measured before, immediately after, and 15 minutes after the first intervention session and after 4 weeks of intervention. A follow-up postintervention measurement would be taken after 4 weeks. The SRT group will train on an SRT device (SRT Zeptor Medical plus noise, Zeptoring). The WBV group will train on a Galileo vibration device (Novotec Medical), while the BLT group will perform balance exercises. All participants shall train 3 times a week for a period of 4 weeks. Mixed ANOVA will be used to determine the main and effects of interactions within (before intervention, post intervention 1, post intervention 2, post intervention 3, and follow-up) and between (SRT, WBV, and BLT) factors on the study outcome variables. Results: Recruitment of participants started in May 2021, and as of May 2022, a total of 20 patients have been enrolled in the study. All participants are expected to have completed the trial by the end of 2022, and data analysis will commence thereafter. Conclusions: The outcome of this study will shed closer light on the effects of SRT, WBV, and BLT on pain and function in patients with chronic neck pain. [ABSTRACT FROM AUTHOR]

Takafumi Hattori,1,2 Kazuhiro Shimo,3 Yuto Niwa,1 Yuji Tokiwa,1 Takako Matsubara1,3 1Faculty of Rehabilitation, Kobe Gakuin University Graduate School, Kobe, Hyogo, Japan; 2Department of Rehabilitation, Maehara Orthopedics Rehabilitation Clinic, Obu, Aichi, Japan; 3Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Hyogo, JapanCorrespondence: Kazuhiro ShimoDepartment of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe, Hyogo, 651-2180, JapanTel/Fax +81-78-974-2461Email shimo@reha.kobegakuin.ac.jpPurpose: Pain and joint deformity are the most common symptoms of hip osteoarthritis (OA). However, no significant association between pain and severity of radiographic lesions has been reported. Recently, central sensitization has been suggested as an underlying mechanism of pain in OA. We investigated the involvement of radiologic severity or central sensitization in the clinical manifestation of hip OA with various degrees of joint deformity.Patients and Methods: We included 39 patients with hip OA and divided them into two groups according to the severity of the hip pain: strong/severe (numerical rating scale, NRS≥ 6) and mild/moderate (NRS< 6). We assessed the radiologic severity of OA using the Kellgren-Lawrence (K-L) scale and minimum joint space width (mJSW). We conducted quantitative sensory testing (QST) that included pressure pain threshold (PPT) and temporal summation of pain (TSP) at hip, tibialis anterior (leg), and extensor carpi radialis longus (arm) on the affected side. We examined the difference of radiologic assessment and QST results between each group and the correlation of the NRS with the radiologic assessment and QST results.Results: There was no significant difference in the K-L scale and mJSW between patients with strong/severe and mild/moderate joint pain. Strong/severe pain patients demonstrated a lower PPT at all measurement sites and higher TSP at the hip and leg than the mild/moderate pain patients. In addition, NRS was significantly negatively correlated with PPT and positively correlated with TSP at all measurement sites, but not with the K-L scale and mJSW.Conclusion: We reported no significant difference in radiologic severity between patients with strong/severe and mild/moderate joint pain. By contrast, we found a significant difference in central sensitization represented by QST between strong/severe and mild/moderate joint pain groups. These results suggest that central sensitization may be involved in the joint pain of patients with hip OA who complain of severe pain despite less severe joint deformity.Keywords: hip osteoarthritis, quantitative sensory testing, pressure pain threshold, temporal summation of pain

Abstract Background Pain hypersensitivity can be assessed using Quantitative Sensory Testing (QST) and is associated with persistent low back pain. Spinal manipulation appears to modify pain hypersensitivity, and this could function as one mechanism leading to clinical improvements. In the current study, we applied a comprehensive QST battery to assess pain sensitivity in a cohort of low back pain patients before and after spinal manipulation to improve our understanding of the association between QST and clinical improvements. This study addresses two questions: Are clinical improvements following spinal manipulation in low back pain patients contingent on pain hypersensitivity, and does pain sensitivity change following spinal manipulation? Methods We performed a secondary analysis of data from a randomized clinical trial. One hundred and thirty-two participants with persistent LBP were treated with spinal manipulation four times over two weeks. Patient-reported outcomes and QST were assessed at baseline, after the fourth spinal manipulation session, and 14-days later. The clinical outcomes were changes in low back pain intensity and disability. Using latent profile analysis, we categorized the participants into clusters depending on their baseline QST scores. We used linear mixed models to examine the association between clusters and changes in patient-reported outcomes and QST. Results Two clusters emerged: a Sensitized and a Not sensitized. The former had significantly lower regional pressure and thermal pain thresholds, remote pressure pain tolerance, and lower inhibitory conditioned pain modulation than the Not sensitized group. However, we only found between-cluster differences for regional pressure pain threshold following spinal manipulation. Thus, the clusters were not associated with patient-reported pain and disability changes or the remaining QST outcomes. Conclusions We report that the baseline QST profile was not associated with clinical improvements following spinal manipulation. We did observe a substantial change for regional pressure pain threshold, which suggests that any effect of spinal manipulation on pain sensitivity is most likely to be observed as changes in regional, mechanical pain threshold. However, the mechanism that invokes clinical improvement and pain sensitivity changes appear distinct. Due to methodological caveats, we advise caution when interpreting the results. Trial registration Clinical.Trial.gov identifier: NCT04086667 , registered 11 September 2019 – Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04086667

Background: Changes in pain sensitivity are a commonly suggested mechanism for the clinical effect of spinal manipulative therapy (SMT). Most research has examined pressure pain thresholds (PPT) and has primarily been conducted in controlled experimental setups and on asymptomatic populations. Many important factors are likely to differ between research and clinical settings, which may affect PPT changes following SMT. Therefore, we planned to investigate PPT before and after clinical chiropractic care and investigate relationships with various potentially clinically-relevant factors. Methods: We recruited participants from four Danish chiropractic clinics between May and August 2021. A total of 129 participants (72% of the invited) were included. We measured PPT at eight pre-determined test sites (six spinal and two extra-spinal) immediately before (pre-session) and immediately after (post-session) the chiropractic consultation. We used regression analyses to investigate PPT changes, including the following factors: (i) vertebral distance to the nearest SMT site, (ii) rapid clinical response, (iii) baseline PPT, (iv) number of SMTs performed, (v) at the region of clinical pain compared to other regions, and (vi) if other non-SMT treatment was provided. We also performed topographic mapping of pre-session PPTs. Results: After the consultation, there was a non-significant mean increase in PPT of 0.14 kg (95% CIs = − 0.01 to 0.29 kg). No significant associations were found with the distance between the PPT test site and nearest SMT site, the clinical response of participants to treatment, the pre-session PPT, the total number of SMTs performed, or the region/s of clinical pain. A small increase was observed if myofascial treatment was also provided. Topographic mapping found greater pre-session PPTs in a caudal direction, not affected by the region/s of clinical pain. Conclusions: This study of real-world chiropractic patients failed to demonstrate a substantial local or generalized increase in PPT following a clinical encounter that included SMT. This runs counter to prior laboratory research and questions the generalizability of highly experimental setups investigating the effect of SMT on PPT to clinical practice. [ABSTRACT FROM AUTHOR]

Objective: There is an unexplained association between disturbed sleep and migraine. In this blinded crossover study, we investigate if experimental sleep restriction has a different effect on pain thresholds and suprathreshold pain in interictal migraineurs and controls. Methods: Forearm heat pain thresholds and tolerance thresholds, and trapezius pressure pain thresholds and suprathreshold pain were measured in 39 interictal migraineurs and 31 healthy controls after two consecutive nights of partial sleep restriction and after habitual sleep. Results: The effect of sleep restriction was not significantly different between interictal migraineurs and controls in the primary analyses. Pressure pain thresholds tended to be lower (i.e., increased pain sensitivity) after sleep restriction in interictal migraineurs compared to controls with a 48-hour preictal-interictal cut-off (p = 0.061). We found decreased pain thresholds after sleep restriction in two of seven migraine subgroup comparisons: heat pain thresholds decreased in migraineurs with lower pain intensity during attacks (p = 0.005) and pressure pain thresholds decreased in migraineurs with higher severity of photophobia during attacks (p = 0.031). Heat pain thresholds tended to decrease after sleep restriction in sleep-related migraine (p = 0.060). Sleep restriction did not affect suprathreshold pain measurements in either group. Conclusion: This study could not provide strong evidence for an increased effect of sleep restriction on pain sensitivity in migraineurs compared to healthy controls. There might be a slightly increased effect of sleep restriction in migraineurs, detectable using large samples or more pronounced in certain migraine subgroups. [ABSTRACT FROM AUTHOR]