Reliability of 2 Protocols for Assessing Pressure Pain Threshold in Healthy Young Adults

Physical activity is predictive of conditioned pain modulation in healthy individuals: a cross-sectional study

Even in healthy populations, conditioned pain modulation (CPM) magnitude varies. This may be accounted for by (non-)modifiable factors, including physical activity. Yet, little research has thoroughly examined physical activity and its relation with CPM magnitude in a representative sample. Therefore, the present study investigated the predictive effect of physical activity on CPM magnitude in 105 healthy adults. Physical activity was assessed during seven consecutive days by self-report using the International Physical Activity Questionnaire and by monitored-based accelerometry. CPM was examined using a heterotopic noxious conditioning stimulation protocol during which the effect of a hot water conditioning stimulus on pressure pain thresholds was evaluated. Comparative, correlation, and hierarchical linear regression analyses were performed. Report-based walking predicts 4.8% of variance in pain modulatory capacity, moderate physical activity predicts 10.2% of variance in pain modulatory capacity, and report-based time spent on total physical activity predicts 7.0% of variance in pain modulatory capacity. More MET-minutes/week spent on total physical activity, including walking and moderate physical activity is associated with greater pain modulatory capacity. The findings of this study add to the limited evidence on the predictive effect of physical activity on CPM. It urges to consider physical activity a confounding factor when examining CPM. The current study provides evidence that a physically active lifestyle benefits endogenous pain modulation in healthy adults. Given its potential, walking and moderate-intensity physical activity might be achievable treatment strategies for pain patients known to have impaired CPM. PERSPECTIVE: The results of this article show that a physically active lifestyle including larger amounts of walking and moderate activity predict greater pain modulatory capacity. TRIAL REGISTRATION: This study has not been preregistered.

TDCS for parkinson's disease disease-related pain: A randomized trial

OBJECTIVE

To evaluate the effects of transcranial direct current stimulation (tDCS) on Parkinson's disease (PD)-related pain.

METHODS

This triple-blind randomized controlled trial included twenty-two patients (age range 38-85, 10 male) with PD-related pain. Eleven subjects received ten sessions of 20 minutes tDCS over the primary motor cortex contralateral to pain at 2 mA intensity. Eleven subjects received sham stimulation. Outcome measures included changes in the Kinǵs Parkinsońs Pain Scale (KPPS), Brief Pain Inventory (BPI), widespread mechanical hyperalgesia (WMH), temporal summation of pain (TS), and conditioned pain modulation (CPM).

RESULTS

Significant differences were found in KPPS between groups favoring the active-tDCS group compared to the sham-tDCS group at 15-days follow-up (p = 0.014) but not at 2 days post-intervention (p = 0.059). The active-group showed significant improvements over the sham-group after 15 days (p = 0.017). Significant changes were found in CPM between groups in favor of active-tDCS group at 2 days post-intervention (p = 0.002) and at 15 days (p = 0.017). No meaningful differences were observed in BPI or TS.

CONCLUSIONS

tDCS of the primary motor cortex alleviates perceived PD-related pain, reduces pain sensitization, and enhances descending pain inhibition.

SIGNIFICANCE

This is the first study to test and demonstrate the use of tDCS for improving PD-related pain.

Examining the role of mood in pain-limited treadmill walking duration in young healthy individuals

PURPOSE

The purpose of the study was to examine the effects of acute mood modulation on treadmill walking duration during experimental pain application.

METHODS

This was a repeated measure, within-subject study design. 30 healthy individuals (Males: Females 16:14; age 22.9 ± 2.5 years; height 170.9 ± 9.5 cm; body mass 68.4 ± 14.6 kg) attended a familiarization session and three experimental sessions, whereby they simultaneously viewed emotionally evoking stimulus from the International Affective Picture System (IAPS) and performed two treadmill walking tests (maximum 10 min duration) with a fixed nociceptive input applied to the thigh (pressure cuff). The primary outcome was treadmill walking duration during pain application to achieve a fixed pain score. During walking, mood (Self-Assessment Manikin: SAM 0-9) and pain (numerical rating scale: NRS 0-10) were measured.

RESULTS

Mood valence scores were significantly different in all conditions (p < 0.001), negative (2.4 ± 0.3), neutral (4.9 ± 0.6) and positive (6.6 ± 0.3). There was a significant difference (p = 0.04) in the treadmill walking duration for different mood states. For the primary outcome, post hoc analysis found differences between the negative and positive mood conditions for the treadmill walking durations to reach pain scores of 3 (negative: 224 ± 49 s; positive: 259 ± 60s, effect size [ES]: 0.80), 4 (negative: 262 ± 59 s; positive: 326 ± 90s, ES: 0.92), 5 (negative: 313 ± 86 s; positive: 385 ± 113 s, ES: 0.90), 6 (negative: 367 ± 106 s; positive: 447 ± 113 s, ES: 1.04) and 7 (negative: 423 ± 114 s; positive: 521 ± 110 s, ES: 1.02). There was no significant difference in the treadmill walking duration between the neutral vs negative mood and neutral vs positive mood conditions.

CONCLUSION

These results highlight the potential psychophysiological impacts on the pain experience in healthy individuals and encourages pursuit in strategies to minimize pain-limited exercise, a highly prevalent issue in the chronic pain population.

SIGNIFICANCE

Walking-based rehabilitation, designed to improve physical activity, has been shown to improve pain and disability. However active participation and adherence in walking-based rehabilitation has shown to be jeopardized by pain and pain-related cognitive and behavioural adaptations. This study examined the effect of a shift in mood on pain perception and treadmill walking tolerance. We found that with a worse mood, individuals were less tolerant of pain and walked on the treadmill for a shorter duration. These results suggest that factors which improve mood should be combined with walking-based training to improve tolerance.

The interrater and test-retest reliability of 3 modalities of quantitative sensory testing in healthy adults and people with chronic low back pain or rheumatoid arthritis

Introduction

Quantitative Sensory Testing (QST) modalities used to assess central pain mechanisms require different protocols in people with different musculoskeletal conditions.

Objectives

We aimed to explore the possible effects of musculoskeletal diagnosis and test site on QST interrater and test-retest reliability.

Methods

The study included participants with rheumatoid arthritis (RA, n = 18; QST conducted on lower leg) and low back pain (LBP, n = 25; QST conducted on forearm), plus 45 healthy control participants (n = 20 QST on lower leg and n = 25 QST on forearm). Test-retest reliability was assessed from QST conducted 1 to 3 weeks apart. Quantitative sensory testing modalities used were pressure pain detection threshold (PPT) at a site distant to tissue pathology, temporal summation (TS), and conditioned pain modulation (CPM). Temporal summation was calculated as difference or ratio of single and repeated punctate stimuli and unconditioned thresholds for CPM used single or mean of multiple PPTs. Intraclass correlation coefficients (ICCs) were compared between different subgroups.

Results

High to very high reliability was found for all assessments of PPT and TS across anatomical sites (lower leg and forearm) and participants (healthy, RA, and LBP) (ICC ≥ 0.77 for PPT and ICC ≥ 0.76 for TS). Reliability was higher when TS was calculated as a difference rather than a ratio. Conditioned pain modulation showed no to moderate reliability (ICC = 0.01-0.64) that was similar between leg or forearm, and between healthy people and those with RA or LBP.

Conclusion

PPT and TS are transferable tools to quantify pain sensitivity at different testing sites in different musculoskeletal diagnoses. Low apparent reliability of CPM protocols might indicate minute-to-minute dynamic pain modulation.

Cervical sensitivity, range of motion and strength in individuals with shoulder pain: A cross-sectional case control study

OBJECTIVES

To assess whether cervical sensitivity, range of motion (ROM) and strength are impaired in individuals with shoulder pain and how they interact with sociodemographic and clinical data.

METHODS

Forty-eight individuals with shoulder pain and 48 asymptomatic matched ones were included. Pressure pain thresholds (PPTs) in cervical region and tibialis anterior muscles, ROM of cervical flexion, extension, lateral flexions and rotations and cervical muscle strength of flexion, extension and lateral flexions were assessed. Between-groups comparisons and a logistic multiple regression model were performed.

RESULTS

The symptomatic group showed lower and not meaningful PPTs in trapezius of the unaffected/unmatched side, both sternocleidomastoid muscles, and tibialis anterior and reduced ROM in cervical extension (MD = -9.00°) when compared to the asymptomatic group. No differences were identified in muscle strength. Reduced PPT of the trapezius and reduced cervical extension ROM together accounted for 40.2% of the variance of the chance of presenting shoulder pain.

CONCLUSION

Individuals with shoulder pain have more, but not clinically relevant, cervical sensitivity and lower cervical extension than asymptomatic individuals. The lower the PPT of the upper trapezius and the cervical extension ROM, the higher was the chance to present shoulder pain. Regional interdependence between cervical spine and shoulder may explain cervical physical function alterations in shoulder pain.

Differences between the Perilaryngeal Pressure Pain Thresholds in Asymptomatic Women, Women With Bruxism, and Women With Odynophonia

OBJECTIVE

This study was aimed at comparing perilaryngeal pressure pain thresholds (PPT) among asymptomatic women, women with bruxism, and women with odynophonia.

DESIGN

Observational cross-sectional study.

METHODS

Eighty-four women whose age mean was 23.75 (SD, 3.02) years were grouped according to inclusion and exclusion criteria into a group of asymptomatic women (G1), another group of women with bruxism (G2), and another of women with odynophonia (G3). Palpation was used to identify regions of interest for this study, and an analog algometer was used to evaluate perilaryngeal PPT in the previously localized regions. Each PPT evaluation was done twice.

RESULTS

G1 PPT mean were between 1.35 (SD, 0.20) and 2.29 (SD, 0.28) kg/cm2, G2 PPT mean were found between 0.85 (SD, 0.12) and 1.78 (SD, 0.23) kg/cm2, and G3 PPT mean were located between 0.71 (SD, 0.11) and 1.45 (SD, 0.19) kg/cm2. Differences were observed between PPT in the three groups evaluated (P < 0.05). The intra-evaluator agreement between the evaluations performed fluctuated between 60.71% (κ = 0.51) and 92.86% (κ = 0.91).

CONCLUSIONS

There are significant differences between the perilaryngeal PPT of asymptomatic women, women with bruxism, and women with odynophonia. Asymptomatic women had the highest PPT, while odynophonia sufferers had the lowest.

Manual Therapy Effects on Nonspecific Neck Pain Are Not Mediated by Mechanisms Related to Conditioned Pain Modulation: A Randomized Clinical Trial

BACKGROUND

Manual therapy (MT) is a treatment recommended by clinical practice guidelines in the management of patients with neck pain. However, the mechanisms through which MT works remain unknown. The aim of the present study is to investigate if MT is mediated by mechanisms related to conditioned pain modulation (CPM), comparing the effects of painful with a pain-free MT treatment.

METHODS

A two-arm, parallel, randomized controlled clinical trial with concealed allocation and blinding of the outcome assessor was conducted in university students with chronic or recurrent nonspecific neck pain (NSNP). Participants received either a painful or pain-free MT session. Psychophysical variables including pressure pain thresholds, CPM, temporal summation of pain and cold pain intensity were assessed before and immediately after treatment. In addition, changes in neck pain intensity over the following 7 days and self-perceived improvement immediately and 7 days after treatment were assessed.

RESULTS

No significant differences were found between groups in any of the psychophysical variables or in patients' self-perceived improvement. Only a significantly greater decrease in neck pain intensity immediately after treatment was found in the pain-free MT group compared to the painful MT group.

CONCLUSION

The results suggest that the immediate and short-term effects of MT on NSNP are not mediated by CPM-related mechanisms.

The Effect of Praying on Endogenous Pain Modulation and Pain Intensity in Healthy Religious Individuals in Lebanon: A Randomized Controlled Trial

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."

Abdominal examination using pressure pain threshold algometer reflecting clinical characteristics of complementary and alternative medicine in Korea: A systematic review and a brief proposal

BACKGROUND

A review was conducted to determine a pressure algometry measurement during abdominal examination that reflects clinical settings of traditional Korean medicine.

METHODS

After reviewing the previous studies, we have proposed a reference index, common posture and method for performing pressure algometry during abdominal examination. Keyword search using eight databases was performed. To identify the characteristics of pressure algometry during abdominal examination, keywords (e.g., abdomen, abdominal examination) were searched in national Korean databases, including Korean studies Information System (KISS), Research Information Sharing Service (RISS), and Oriental Medicine Advanced Searching Integrated System (OASIS). To examine the methods of measuring pressure pain threshold (PPT) with validity and reliability, combination keywords (e.g., PPT, pressure algometry, pressure pain, validity, reliability) were searched in Pubmed, Cochrane library, Google scholar, Ovid Embase, and China Knowledge Resource Integrated Database (CNKI).

RESULTS

A total of 652 articles were identified, and 22 relevant articles were included. The following main indices are proposed as a standardized pressure algometry method during abdominal examination: unit of measurements, measuring tools, target locations, pressure area, pressure rate, posture of patients, and evaluators. Based on the results of the review combined with clinical practice, useful indices for pressure algometer during abdominal examination were derived (target location: CV 12, unit of measurement: MPa, pressure area: 4 cm2, pressure rate: 0.098 MPa/s, posture of patient: supine position, number, and intervals of measurement: three consecutive measurements at intervals of 30 seconds, 5 minutes rest prior to commencement). Postures and method sequence of pressure algometry during abdominal examination are also proposed.

CONCLUSIONS

Using standardized indices, postures and method for abdominal examination in clinical settings will help make objective assessments.

Virtual Reality Animal Rescue World: Pediatric virtual reality analgesia during just noticeable pressure pain in children aged 2-10 years old (crossover design)

BACKGROUND AND AIMS

Excessive pain during medical procedures is a worldwide medical problem. Most scald burns occur in children under 6, who are often undermedicated. Adjunctive Virtual Reality (VR) distraction has been shown to reduce pain in children aged 6-17, but little is known about VR analgesia in young children. This study tests whether desktop VR (VR Animal Rescue World) can reduce the just noticeable pressure pain of children aged 2-10.

METHODS

A within-subject repeated measures design was used. With treatment order randomized, each healthy volunteer pediatric participant underwent brief cutaneous pressure stimuli under three conditions: (1) no distraction, (2) a verbal color naming task (no VR), and (3) a large TV-based desktop VR distraction. A hand-held Wagner pressure pain stimulation device was used to generate just noticeable pain sensations. Participants indicated when a steadily increasing non-painful pressure stimulus first turned into a painful pressure sensation (just noticeable pain).

RESULTS

A total of 40 healthy children participated (43% aged 2-5 years; and 57% aged 6-10 years). Compared to the no distraction condition, the 40 children showed significant VR analgesia (i.e., a significant reduction in pain sensitivity during the VR Animal Rescue World condition), t(39) = 9.83, p < 0.001, SD = 6.24. VR was also significantly more effective at reducing pain sensitivity vs. an auditory color naming task, t(39) = 5.42, p < 0.001, SD = 5.94. The subset of children aged 2-5 showed significant reductions in pain during VR. Children under 6 showed greater sensitivity to pain during no distraction than children aged 6-10.

CONCLUSION

During no distraction, children under 6 years old were significantly more sensitive to pain than children aged 6-10. Virtual reality (VR) significantly reduced the "just noticeable" pressure pain sensitivity of children in both age groups.

Chronic temporomandibular disorders are associated with higher propensity to develop central sensitization: a case-control study

ABSTRACT

Temporomandibular disorders (TMD) include a group of musculoskeletal disorders that may involve increased responsiveness of nociceptive neurons in the central nervous system (ie, central sensitization). To test this hypothesis further, this study examined whether, as compared with healthy subjects, patients with chronic TMD have a greater propensity to develop secondary mechanical hyperalgesia-a phenomenon that can be confidently attributed to central sensitization. In this case-control study, we assessed the area of secondary mechanical hyperalgesia induced experimentally by delivering high-frequency electrical stimulation (HFS) to the volar forearm skin in 20 participants with chronic TMD and 20 matched healthy controls. High-frequency electrical stimulation consisted in 12 trains of constant-current electrical pulses (5 mA) delivered at 42 Hz. The area of secondary mechanical hyperalgesia was evaluated 30 minutes after applying HFS. The area of secondary mechanical hyperalgesia induced by HFS was on average 76% larger in the chronic TMD group (M = 67.7 cm 2 , SD = 28.2) than in the healthy control group (M = 38.4 cm 2 , SD = 14.9; P = 0.0003). Regarding secondary outcomes, there was no group difference in the intensity of secondary mechanical hyperalgesia, but allodynia to cotton after HFS was more frequent in the chronic TMD group. To the best of our knowledge, this is the first study to show that individuals with chronic TMD have an increased propensity to develop secondary hyperalgesia in a site innervated extratrigeminally. Our results contribute to a better understanding of the pathophysiology of chronic TMD.

Specific versus non-specific exercises for the neck extensor muscles in women with chronic idiopathic neck pain: A randomized controlled trial

BACKGROUND

Structural and functional impairments of the cervical extensor muscles have been demonstrated in people with neck pain. A global exercise approach targeting all neck extensor muscles has shown positive effects in this population. However, to date, the efficacy of exercises specifically targeting the deep neck extensors has neither been tested nor compared to global exercises for the neck extensors.

OBJECTIVES

To compare the effects on pain and disability of a specific lower deep neck extensors (SLDNE) versus a general neck extensor (GNE) exercise program in women with chronic idiopathic neck pain.

METHODS

Fourty-three women with chronic idiopathic neck pain were randomly allocated to either a six-week SLDNE or a GNE exercise program. As primary outcome, neck disability was measured with the Neck Disability Index (NDI). Secondarily, pain intensity (VAS), cervical ROM, pressure pain thresholds (PPTs), cervical and thoracic posture and self-perceived benefit of treatment (GROC) were also measured. Every outcome was measured at baseline and immediately after treatment, except NDI, which was also measured at 6-months follow-up. The GROC was only assessed post-intervention.

RESULTS

Both exercise programs lead to reduced neck disability immediately post-intervention (within-group mean difference [MD] = -6.09; 95% Confidence Interval [CI]: 7.75, -4.42 and -4.73; 95%CI: 6.57, -2.91 respectively) and at the 6-months follow-up (-4.47; 95%CI: 6.41, -2.53 and -4.74; 95%CI: 6.50, -2.97), but with no between group differences. Similar results were found for pain intensity post-intervention, with no between group interaction (within-group MD = -20.87 mm; 95% CI: 28.55, -13.19 and -18.00 mm; 95%CI: (-26.24, -9.76) for SLDNE and GNE groups, respectively). GROC improved after both interventions without any between-group difference.

CONCLUSIONS

A six-week exercise program specifically targeting the lower deep neck extensors lead to comparable outcomes as a general neck extensor exercise program in women with chronic idiopathic neck pain.

A protocol for a randomized trial on pain neuroscience education vs. routine physical therapy in people with chronic neck pain

The aim of this study is to investigate the effects of combining routine physical therapy with pain neuroscience education (PNE) on psychosocial factors, physical performance, and the experienced pain in patients with chronic neck pain (CNP). This study is a double-blind randomized clinical trial in which patients will be randomly allocated to two groups, routine physical therapy with and without PNE. Patients will be assessed at the baseline, post intervention, and three months later. The results of this research will be used to establish effectiveness of treatment strategies for CNP. Due to the rigorous scientific methods used in this research, the suggested interventions would be clinically applicable in the health care systems.

Taking the strain: An examination of upper back musculoskeletal tissue sensitivity in relation to upper back pain and breast size. A cross-sectional study

BACKGROUND

The physiological basis for upper back pain experienced by women with large breasts is unclear but could relate to sensitivity of musculoskeletal tissues strained from the postural adaptations to large breasts. The aim of this cross-sectional study was to examine if upper back pain and breast size were associated with greater localised sensitivity of upper back musculoskeletal tissues.

METHODS

119 healthy postmenopausal women (mean age 61 years) had their upper back pain (numerical rating scale), breast size (breast size score), and upper back tissue sensitivity (pressure pain thresholds (digital algometry, kPa)) assessed. The pressure pain thresholds of six skeletal sites (T2, T4, T6, T8, T10 and T12) and six muscular sites (pectoralis major, levator scapulae, sternocleidomastoid, and upper, middle, and lower trapezius muscles) were examined. Linear mixed models with random subject effects were used to evaluate differences in sensitivity at each anatomical site between participants grouped by upper back pain (nil-mild, moderate-severe) and breast size (small, large).

FINDINGS

For most sites, the differences in sensitivity between upper back pain groups were highly significant (P < 0.002) with significantly lower pressure pain thresholds (Mean difference (MD): 74.6 to 151.1 kPa) recorded for participants with moderate-severe upper back pain. There were no differences in sensitivity between breast size groups.

INTERPRETATION

Increased upper back musculoskeletal sensitivity is related to perceived upper back pain but not to breast size. It remains unclear if and how structural or mechanical factors related to breast size contribute to upper back pain in women with large breasts.

No relevant differences in conditioned pain modulation effects between parallel and sequential test design. A cross-sectional observational study

Background

Conditioned pain modulation (CPM) is measured by comparing pain induced by a test stimulus with pain induced by the same test stimulus, either during (parallel design) or after (sequential design) the conditioning stimulus. Whether design, conditioning stimulus intensity and test stimulus selection affect CPM remains unclear.

Methods

CPM effects were evaluated in healthy participants (N = 89) at the neck, forearm and lower leg using the cold pressor test as the conditioning stimulus. In three separate experiments, we compared the impact of (1) design (sequential versus parallel), (2) conditioning stimulus intensity (VAS 40/100 versus VAS 60/100), and (3) test stimulus selection (single versus dual, i.e., mechanical and thermal). Statistical analyses of the main effect of design (adjusted for order) and experiment were conducted using linear mixed models with random intercepts.

Results

No significant differences were identified in absolute CPM data. In relative CPM data, a sequential design resulted in a slightly lower CPM effect compared to a parallel design, and only with a mechanical test stimulus at the neck (−6.1%; 95% CI [−10.1 to −2.1]) and lower leg (−5.9%; 95% CI [−11.7 to −0.1]) but not forearm (−4.5%; 95% CI [−9.0 to 0.1]). Conditioning stimulus intensity and test stimulus selection did not influence the CPM effect nor the difference in CPM effects derived from parallel versus sequential designs.

Conclusions

Differences in CPM effects between protocols were minimal or absent. A parallel design may lead to a minimally higher relative CPM effect when using a mechanical test stimulus. The conditioning stimulus intensities assessed in this study and performing two test stimuli did not substantially influence the differences between designs nor the magnitude of the CPM effect.

Median Nerve Neural Mobilization Adds No Additional Benefit When Combined with Cervical Lateral Glide in the Treatment of Neck Pain: A Randomized Clinical Trial

BACKGROUND

This study aimed to compare the effectiveness of cervical lateral glide (CLG) added to median nerve neural mobilization (MNNM) in patients with neck pain (NP).

METHODS

A single-blinded randomized controlled clinical trial was carried out in a Pain Management Unit from a Hospital. A total sample of 72 patients with NP was recruited from a hospital. Patients were randomized to receive isolated CLG (n = 36) or CLG + MNNM (n = 36). Bilateral elbow extension range of motion (ROM) on upper limb neurodynamic test 1 (ULNT1), bilateral pressure pain thresholds (PPT) on the median nerve at elbow joint, C6 zygapophyseal joint and tibialis anterior, Visual analogue scale (VAS), body chart distribution of pain, active cervical ROM (CROM), Neck Disability Index (NDI), and Tampa Scale of Kinesiophobia (TSK-11) were measured at baseline as well as immediately, 15 days, and 1 month after treatment.

RESULTS

There were no statistically significant interactions (p > 0.05) between treatment and time for median nerve mechanosensitivity outcomes, pain intensity, symptom distribution, and PPT of the widespread pain assessment, as well as cervical function, and kinesiophobia.

CONCLUSIONS

MNNM gave no additional benefit to CLG in patients with NP regarding pain intensity, symptom distribution, mechanosensitivity, functionality, and kinesiophobia. Only two treatment sessions and the short follow-up are important issues, therefore, justifying further studies to answer the research question with better methodology.

Effects of Different Kinesio-Taping Applications for Delayed Onset Muscle Soreness after High-Intensity Interval Training Exercise: A Randomized Controlled Trial

Objectives

Kinesio-taping (KT) is used commonly for the management and prevention of sports injuries. High-intensity interval training (HIIT) is a common muscle strength training and often accompanies delayed onset muscle soreness (DOMS) to interfere with individuals' exercise adherence. So, we compared the effects on muscle pain, thigh edema, and muscle strength for two kinds of KT applications on quadriceps muscles with DOMS after HIIT exercise.

Methods

This is a randomized controlled trial study, which was conducted in a sports medicine laboratory of the college, and all data were collected between February 2019 and February 2020. Healthy participants were recruited from a local university and nearby community by announcements. They were randomly assigned to Group Y (Y-shaped KT application), Group CC (crisscross weave KT application), or Group CON (non-KT). All of them were assessed and used KT following the HIIT exercise, which was used to induce DOMS in the quadriceps muscles. Two different KT applications were, respectively, used in Groups Y and CC, whereas Group CON received no KT application. The visual analog scale (VAS), pressure pain threshold (PPT), thigh circumference, and muscle strength were assessed on the quadriceps femoris muscles before, immediately after, and at 24, 48, and 72 h after exercise.

Results

A total of 38 participants completed the study trial. There were no significant differences in gender, age, height, weight, BMI, body fat, and muscle mass among the three groups (p > 0.05). HIIT had a significant impact on muscle soreness, as revealed by the increase in VAS at 24 h after exercise. The results revealed no effect on VAS, PPT, and thigh circumference in Group Y and Group CC (all p > 0.05). Additionally, muscle strength was significantly higher in Group CC at 24 h and 48 h after exercise compared with Groups Y and Group CON (p < 0.05).

Conclusion

In summary, this experiment reveals no evidence of the effectiveness of Y-shaped and crisscross weave KT applications in the improvement of DOMS pain and edema in the quadriceps muscle. However, the crisscross weave KT application on the quadriceps muscle improved muscle strength recovery after HIIT, but the Y-shaped KT application did not exert this effect. This finding may be useful for muscle strength recovery during HIIT or continuous running competitions.

Effect of photobiomodulation therapy on painful temporomandibular disorders

To evaluate the effect of photobiomodulation therapy (PBMT) on painful temporomandibular disorders (TMD) patients in a randomized, double-blinded, placebo-controlled manner. Participants were divided into a masseter myalgia group (n = 88) and a temporomandibular joint (TMJ) arthralgia group (n = 87) according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Both groups randomly received PBMT or placebo treatment once a day for 7 consecutive days, one session. The PBMT was applied with a gallium-aluminum-arsenide (GaAlAs) laser (wavelength = 810 nm) at pre-determined points in the masseter muscle (6 J/cm², 3 regions, 60 s) or TMJ region (6 J/cm², 5 points, 30 s) according to their most painful site. Pain intensity was rated on a 0–10 numerical rating scale (NRS) and pressure pain thresholds (PPT) and mechanical sensitivity mapping were recorded before and after the treatment on day 1 and day 7. Jaw function was assessed by pain free jaw opening, maximum unassisted jaw opening, maximum assisted jaw opening, maximum protrusion and right and left excursion. Data were analyzed with a mixed model analysis of variance (ANOVA). Pain intensity in arthralgia patients decreased over time (P < 0.001) for both types of interventions, however, PBMT caused greater reduction in pain scores than placebo (P = 0.014). For myalgia patients, pain intensity decreased over time (P < 0.001) but without difference between interventions (P = 0.074). PPTs increased in both myalgia (P < 0.001) and TMJ arthralgia patients over time (P < 0.001) but without difference between interventions (P ≥ 0.614). Overall, PBMT was associated with marginally better improvements in range of motion compared to placebo in both myalgia and arthralgia patients. Pain intensity, sensory function and jaw movements improve after both PBMT and placebo treatments in myalgia and arthralgia patients indicating a substantial non-specific effect of PBMT.

The addition of thoracic mobilization to aerobic exercise did not alter autonomic function and pain pressure threshold acutely in asymptomatic young people: A randomized controlled trial

OBJECTIVE

To analyze the influence of acute aerobic exercise (AE) plus thoracic mobilization in pain perception and autonomic nervous system response in healthy adults.

DESIGN

Randomized clinical trial.

METHODS

Forty-eight asymptomatic adults were allocated into one of three groups: 1) Aerobic Exercise (AE), 2) Aerobic Exercise + Mobilization (AE + M), and 3) Placebo. Participants from groups AE and AE + M ran for 5 min on a treadmill with a 75-85% of age-predicted heart rate. Participants from AE + M group also received a rotatory thoracic passive accessory intervertebral mobilization at T4 after running. Participants from the Placebo group received placebo mobilization. We mesured the autonomic system modulation through Heart Rate Variability (HRV) (time-domain, frequency-domain, and non-linear variables). We measured Pressure Pain Threshold (PPT) with a handheld digital algometer.

RESULTS

While aerobic exercise increased the sympathetic outflow and reduced the HRV, the addition of vertebral mobilization to exercise had no further effect on autonomic system modulation. There was no change in PPT in any group. Besides, there was no correlation between HRV and PPT.

CONCLUSION

Thoracic mobilization did not increase the sympathetic response induced by aerobic exercise. Moreover, exercise alone or exercise plus thoracic mobilization did not change the PPT.

New Approaches Based on Non-Invasive Brain Stimulation and Mental Representation Techniques Targeting Pain in Parkinson's Disease Patients: Two Study Protocols for Two Randomized Controlled Trials

Pain is an under-reported but prevalent symptom in Parkinson’s Disease (PD), impacting patients’ quality of life. Both pain and PD conditions cause cortical excitability reduction and non-invasive brain stimulation. Mental representation techniques are thought to be able to counteract it, also resulting effectively in chronic pain conditions. We aim to conduct two independent studies in order to evaluate the efficacy of transcranial direct current stimulation (tDCS) and mental representation protocol in the management of pain in PD patients during the ON state: (1) tDCS over the Primary Motor Cortex (M1); and (2) Action Observation (AO) and Motor Imagery (MI) training through a Brain-Computer Interface (BCI) using Virtual Reality (AO + MI-BCI). Both studies will include 32 subjects in a longitudinal prospective parallel randomized controlled trial design under different blinding conditions. The main outcomes will be score changes in King’s Parkinson’s Disease Pain Scale, Brief Pain Inventory, Temporal Summation, Conditioned Pain Modulation, and Pain Pressure Threshold. Assessment will be performed pre-intervention, post-intervention, and 15 days post-intervention, in both ON and OFF states.

Pressure pain threshold and temporal summation in adults with episodic and persistent low back pain trajectories: a secondary analysis at baseline and after lumbar manipulation or sham

BACKGROUND

People with chronic low back pain (LBP) typically have increased pain sensitivity compared to healthy controls, however its unknown if pain sensitivity differs based on LBP trajectory at baseline or after manual therapy interventions. We aimed to compare baseline pressure pain threshold (PPT) and temporal summation (TS) between people without LBP, with episodic LBP, and with persistent LBP, and to compare changes over time in PPT and TS after a lumbar spinal manipulation or sham manipulation in those with LBP.

METHODS

Participants were aged 18-59, with or without LBP. Those with LBP were categorised as having either episodic or persistent LBP. PPT and TS were tested at baseline. LBP participants then received a lumbar spinal manipulation or sham, after which PPT and TS were re-tested three times over 30 min. Generalised linear mixed models were used to analyse data.

RESULTS

One hundred participants (49 female) were included and analysed. There were 20 non-LBP participants (mean age 31 yrs), 23 episodic LBP (mean age 35 yrs), and 57 persistent LBP (mean age 37 yrs). There were no significant differences in PPT or TS between groups at baseline. There was a non-significant pattern of lower PPT (higher sensitivity) from the non-LBP group to the persistent LBP group at baseline, and high variability. Changes in PPT and TS after the interventions did not differ between the two LBP groups.

DISCUSSION

We found no differences between people with no LBP, episodic LBP, or persistent LBP in baseline PPT or TS. Changes in PPT and TS following a lumbar manual therapy intervention do not appear to differ between LBP trajectories.

TRIAL REGISTRATION

The trial was prospectively registered with ANZCTR (ACTRN12617001094369).

Reliability of temporal summation, thermal and pressure pain thresholds in a healthy cohort and musculoskeletal trauma population

Traumatic injuries affect approximately 978 million people worldwide with 56.2 million requiring inpatient care. Quantitative sensory testing (QST) can be useful in predicting outcome following trauma, however the reliability of multiple QST including temporal summation (TS), heat and cold pain thresholds (HPT, CPT) and pressure pain thresholds (PPT) is unknown. We assessed intra (between day) and inter-rater (within day) reliability of QST in asymptomatic participants (n = 21), and inter-rater (within day) reliability in participants presenting with acute musculoskeletal trauma (n = 25). Intra-class correlations with 95% confidence intervals (ICC 3,2), standard error of measurement (SEM) and Bland Altman Plots for limits of agreement were calculated. For asymptomatic participants, reliability was good to excellent for HPT (ICC range 0.76–0.95), moderate to good for PPT (ICC range 0.52–0.93), with one site rated poor (ICC 0.41), and poor to excellent for TS scores (ICC range 0.20–0.91). For musculoskeletal trauma participants reliability was good to excellent for HPT and PPT (ICC range 0.76–0.86), and moderate to good reliability for TS (ICC range 0.69–0.91). SEM for HPT for both sets of participants was ~1°C and an average of 7N for asymptomatic participants and less than 8N for acute musculoskeletal trauma participants for PPT. This study demonstrates moderate to excellent intra and inter-rater reliability for HPT and PPT in asymptomatic participants and good to excellent inter-rater reliability for acute musculoskeletal trauma participants, with TS showing more variability for both sets of participants. This study provides foundations for future work evaluating the sensory function over time following acute musculoskeletal trauma.

What is the effect of spinal manipulation on the pressure pain threshold in young, asymptomatic subjects? A randomized placebo-controlled trial, with a cross-over design

BACKGROUND

Spinal manipulation (SM) has been shown to have an effect on the pressure pain threshold (PPT) in asymptomatic subjects, but SM has never been compared in studies on this topic to a validated sham procedure. We investigated the effect of SM on the PPT when measured i) in the area of intervention and ii) in an area remote from the intervention. In addition, we measured the size and duration of the effect.

METHOD

In a randomized cross-over trial, 50 asymptomatic chiropractic students had their PPT measured at baseline, immediately after and every 12 min after intervention, over a period of 45 min, comparing values after SM and a previously validated sham. The trial was conducted during two sessions, separated by 48 h. PPT was measured both regionally and remotely from the 'treated' thoracic segment. Blinding of study subjects was tested with a post-intervention questionnaire. We used mixed linear regression with the baseline value and time as co-variates. If a significant difference were found between groups, then an effect size would be calculated using Cohen's d or Hedge's h coefficient. Statistical significance was set at p < 0.05.

RESULTS

Study subjects had been successfully blinded. No statistically significant differences were found between SM and sham estimates, at any time or anatomical location.

CONCLUSION

When compared to a valid sham procedure and with successfully blinded subjects, there is no regional or remote effect of spinal manipulation of the thoracic spine on the pressure pain threshold in a young pain-free population.

No difference in pressure pain threshold and temporal summation after lumbar spinal manipulation compared to sham: A randomised controlled trial in adults with low back pain

BACKGROUND

Changes in quantitative sensory tests have been observed after spinal manipulative therapy (SMT), particularly in pressure pain thresholds (PPT) and temporal summation (TS). However, a recent systematic review comparing SMT to sham found no significant difference in PPT in patients with musculoskeletal pain. The sham-controlled studies were generally low quality, and conclusions about other quantitative sensory tests could not be made.

OBJECTIVES

We aimed to perform a sham-controlled study with the specific objective of investigating changes in PPT and TS short-term after lumbar SMT compared to sham manipulation in people with low back pain.

METHODS

This was a double-blind randomised controlled trial comparing high-velocity low-amplitude lumbar SMT against sham manipulation in participants with low back pain. Primary outcome measures were PPT at the calf, lumbar spine and shoulder, and TS at the hands and feet. These were measured at baseline, then immediately, 15 min and 30 min post-intervention.

RESULTS

Eighty participants (42 females) were included in the analyses (mean age 37 years), with 40 participants allocated to each intervention group. Significant between-group differences were only observed for calf PPT, which could be explained by a decrease in PPT (increased sensitivity) after SMT and an increase after sham. Feet TS decreased significantly over time after both SMT and sham, and any other changes over time were inconsistent.

CONCLUSIONS

Our results suggest that lumbar SMT does not have a short-term hypoalgesic effect, as measured with PPT and TS, when compared to sham manipulation in people with low back pain.

People with musculoskeletal shoulder pain demonstrate no signs of altered pain processing

BACKGROUND

Central sensitisation may contribute to persistent musculoskeletal shoulder pain. Few studies have provided a comprehensive sensory and psychosocial evaluation of this population.

OBJECTIVE

To comprehensively assess whether sensory function and psychosocial aspects are impaired in people with shoulder pain and whether age, gender and clinical outcomes are related to impaired sensory function.

STUDY DESIGN

Observational case-control study.

METHODS

Twenty-three participants with musculoskeletal shoulder pain and 23 age- and gender-matched healthy participants were included. Static (pressure and thermal pain thresholds) and dynamic (temporal summation) quantitative sensory testing was performed bilaterally at the shoulder and remote tibialis anterior muscle. Conditioned pain modulation was measured at the affected/matched shoulder. Shoulder function (SPADI), depression, anxiety and stress (DASS-21) and health-related quality of life (EQ-5D-5L) were also measured. Comparisons were performed between body regions and groups. Age and gender were included as factors in analyses. Clinical outcomes were tested for correlation with sensory measures.

RESULTS

Shoulder pain group had higher local pressure pain threshold (i.e., hypoalgesia; p = 0.03; Z = 0-5.04), higher SPADI score (p < 0.01; Z = -5.76) and higher EQ-5D-5L (p < 0.01; Z = 5.23) compared to the control group. There was no difference between groups for thermal pain sensitivity, dynamic sensory testing or psychological measures.

CONCLUSION

People with shoulder pain demonstrated mechanical hypoalgesia, increased upper limb disability and poorer quality of life compared with healthy controls. Central sensitisation seems not be a characteristic of musculoskeletal shoulder pain although it could be present in a subgroup of patients.

Manipulation-induced hypoalgesia in musculoskeletal pain populations: a systematic critical review and meta-analysis

Background

Manipulation-induced hypoalgesia (MIH) represents reduced pain sensitivity following joint manipulation, and has been documented in various populations. It is unknown, however, whether MIH following high-velocity low-amplitude spinal manipulative therapy is a specific and clinically relevant treatment effect.

Methods

This systematic critical review with meta-analysis investigated changes in quantitative sensory testing measures following high-velocity low-amplitude spinal manipulative therapy in musculoskeletal pain populations, in randomised controlled trials. Our objectives were to compare changes in quantitative sensory testing outcomes after spinal manipulative therapy vs. sham, control and active interventions, to estimate the magnitude of change over time, and to determine whether changes are systemic or not.

Results

Fifteen studies were included. Thirteen measured pressure pain threshold, and four of these were sham-controlled. Change in pressure pain threshold after spinal manipulative therapy compared to sham revealed no significant difference. Pressure pain threshold increased significantly over time after spinal manipulative therapy (0.32 kg/cm², CI 0.22–0.42), which occurred systemically. There were too few studies comparing to other interventions or for other types of quantitative sensory testing to make robust conclusions about these.

Conclusions

We found that systemic MIH (for pressure pain threshold) does occur in musculoskeletal pain populations, though there was low quality evidence of no significant difference compared to sham manipulation. Future research should focus on the clinical relevance of MIH, and different types of quantitative sensory tests.

Trial registration

Prospectively registered with PROSPERO (registration CRD42016041963).

Effects of Laser Acupuncture on Delayed Onset Muscle Soreness of the Biceps Brachii Muscle: A Randomized Controlled Trial

Objectives

The aim of this study was to explore the effects of laser acupuncture on improvement of recovery and muscle performance in delayed muscle soreness (DOMS) when applied before exercise.

Methods

This randomized, blinded, and controlled study included healthy participants (n = 40) who were randomized into laser acupuncture and placebo groups. Laser acupuncture was applied to the Tianquan (PC2) and Chihtseh acupoints (LU5) at a dose of 36 J and energy density of 9.7 J/cm² before inducing DOMS. The placebo group received sham laser acupuncture with no laser output. Visual analog scale (VAS), proprioception, pressure pain threshold (PPT), arm circumference, and muscle strength were observed at the baseline and 24, 48, 72, and 96 h after induction of DOMS.

Results

Significant changes in the VAS (F_{4,  43.96} = 31.47; p = 0.001), PPT (F_4,  1.35 = 35.07; p = 0.001), normalized arm circumference (F_{4,  0.001} = 3.87; p = 0.005), and normalized muscle strength (F_4,  0.31 = 24.99; p = 0.001) were observed within the groups over time (p < 0.05), but there were no significant differences between the two groups (p > 0.05). Normalized arm circumference was significantly different between the two groups at 48 and 72 h after induction of DOMS (p < 0.05).

Conclusion

Photobiomodulation therapy on Tianquan (PC2) and Chihtseh acupoints (LU5) before the exercise did not significantly decrease DOMS and increase muscle performance. Laser acupuncture as a supplemental therapy seemed to have no effect on DOMS prevention.

No evidence of widespread mechanical pressure hyperalgesia after experimentally induced central sensitization through skin nociceptors

High-frequency stimulation of the skin induces secondary pinprick hyperalgesia but does not affect pressure pain thresholds either locally or at more distant body sites.

Introduction:

An increasing number of clinical studies involving a range of chronic pain conditions report widespread mechanical pressure pain hypersensitivity, which is commonly interpreted as resulting from central sensitization (CS). Secondary hyperalgesia (increased pinprick sensitivity surrounding the site of injury) is considered to be a manifestation of CS. However, it has not been rigorously tested whether CS induced by peripheral nociceptive input involves widespread mechanical pressure pain hypersensitivity.

Objectives:

The aim of this study was to assess whether high-frequency electrical stimulation (HFS), which induces a robust secondary hyperalgesia, also induces a widespread decrease of pressure pain thresholds (PPTs).

Methods:

We measured PPTs bilaterally on the temples (temporalis muscles), on the legs (tibialis anterior muscles), and on the ventral forearm (flexor carpi radialis muscles) before, 20 minutes after, and 45 minutes after applying HFS on the ventral forearm of sixteen healthy young volunteers. To evaluate the presence of secondary hyperalgesia, mechanical pinprick sensitivity was assessed on the skin surrounding the site where HFS was applied and also on the contralateral arm.

Results:

HFS induced a significant increase in mechanical pinprick sensitivity on the HFS-treated arm. However, HFS did not decrease PPTs neither in the area of increased pinprick sensitivity nor at more distant sites.

Conclusion:

This study provides no evidence for the hypothesis that CS, induced after intense activation of skin nociceptors, involves a widespread decrease of PPTs.

Autonomic function and pressure pain threshold following thoracic mobilization in asymptomatic subjects: A randomized controlled trial

OBJECTIVE

To compare the effects of two different mobilization techniques and a placebo intervention applied to the thoracic spine on heart rate variability (HRV) and pressure pain threshold (PPT) in asymptomatic individuals.

METHODS

Sixty healthy asymptomatic subjects aged between 18 and 40 years old were randomized to a single session of one of the three interventions: posterior-to-anterior (PA) rotatory thoracic passive accessory intervertebral mobilization (PAIVM) (PA group), unilateral thoracic PA in slump position (SLUMP group) or placebo intervention (Placebo group). HRV and PPT at C7 and T4 spinous process, first dorsal interossei muscles bilaterally, and muscle belly of tibialis anterior bilaterally were measured before and immediately after the intervention. A univariate analysis of covariance (ANCOVA) adjusted for baseline values assessed the effect of "Group". Pairwise comparisons with Bonferroni adjustment for multiple comparisons were performed.

RESULTS

There were no significant between-group differences for HRV. A significant between-group difference for PPT in the ipsilateral tibia was found favoring the SLUMP group in comparison with the PA group. There were no significant between-group differences for PPT in the other landmarks.

CONCLUSION

A single treatment of thoracic PAIVM in prone lying and slump position did not alter PPT and HRV compared to placebo in asymptomatic subjects.

Blood flow after contraction and cuff occlusion is reduced in subjects with muscle soreness after eccentric exercise

Delayed onset muscle soreness (DOMS) occurs within 1-2 days after eccentric exercise, but the mechanism mediating hypersensitivity is unclear. This study hypothesized that eccentric exercise reduces the blood flow response following muscle contractions and cuff occlusion, which may result in accumulated algesic substances being a part of the sensitization in DOMS. Twelve healthy subjects (five women) performed dorsiflexion exercise (five sets of 10 repeated eccentric contractions) in one leg, while the contralateral leg was the control. The maximal voluntary contraction (MVC) of the tibialis anterior muscle was recorded. Blood flow was assessed by ultrasound Doppler on the anterior tibialis artery (ATA) and within the anterior tibialis muscle tissue before and immediately after 1-second MVC, 5-seconds MVC, and 5-minutes thigh cuff occlusion. Pressure pain thresholds (PPTs) were recorded on the tibialis anterior muscle. All measures were done bilaterally at day 0 (pre-exercise), day 2, and day 6 (post-exercise). Subjects scored the muscle soreness on a Likert scale for 6 days. Eccentric exercise increased Likert scores at day 1 and day 2 compared with day 0 (P<.001). Compared with pre-exercise (day 0), reduced PPT (~25%, P<.002), MVC (~22%, P<.002), ATA diameter (~8%, P<.002), ATA post-contraction/occlusion blood flow (~16%, P<.04), and intramuscular peak blood flow (~23%, P<.03) were found in the DOMS leg on day 2 but not in the control leg. These results showed that eccentric contractions decreased vessel diameter, impaired the blood flow response, and promoted hyperalgesia. Thus, the results suggest that the blood flow reduction may be involved in the increased pain response after eccentric exercise.

Effect of lumbar spinal manipulation on local and remote pressure pain threshold and pinprick sensitivity in asymptomatic individuals: a randomised trial

BACKGROUND

The mechanisms of clinical pain relief associated with spinal manipulative therapy (SMT) are poorly understood. Our objective was to determine whether lumbar high-velocity low-amplitude SMT altered pressure pain threshold (PPT) and pinprick sensitivity (PPS) locally and remotely, how long any change lasted (up to 30 min), and whether changes related to the side of SMT.

METHODS

Thirty-four asymptomatic participants (mean age 22.6 years ±4.0) received a right- or left-sided lumbar SMT. PPT and PPS were measured bilaterally at the calf, lumbar spine, scapula, and forehead before and immediately, 10, 20, and 30 min after intervention. Data were collected between October 2014 and June 2015.

RESULTS

Bilateral calf and lumbar spine PPT increased significantly after 10 - 20 min and was maintained at 30 min (7.2-11.8 % increase). PPS decreased significantly in all locations at various times (9.8 - 22.5 % decrease). At the calf and lumbar spine, PPT increased slightly more ipsilateral to the SMT than contralateral.

CONCLUSIONS

Lumbar SMT reduced deep pressure sensitivity locally and in the lower limbs for at least 30 min, whereas sensitivity to pinprick was reduced systemically. These findings suggest that SMT specifically inhibits deep pressure sensitivity distally. These findings are novel compared to other lumbar SMT studies, and may reflect a local spinal or complex supraspinal analgesic mechanism.

TRIAL REGISTRATION

Registered with the Australian New Zealand Clinical Trials Registry (ACTRN12614000682640).

Test-retest reliability of a new technique with pressure algometry applied to teeth in healthy Chinese individuals

Pressure pain thresholds (PPTs) have been shown to be useful measures of mechanical pain sensitivity in deep tissues. However, clinical methods for measuring mechanical allodynia or hyperalgesia in teeth have not been reported. The aim of this study was to assess the reliability of PPTs in periodontal ligament of healthy Chinese participants. Twenty healthy young adults participated. Pressure pain thresholds were measured at six teeth and in two directions. The tests included three consecutive trials, in two separate sessions, which were performed on the first day by one examiner. After 1-3 wk, an identical protocol was carried out by two examiners, also in two separate sessions. There were no significant differences between repeated measures for all teeth. The PPTs had excellent reliability with high intraclass coefficients (ICCs) across different sessions (ICC: 0.871-0.956), days (ICC: 0.879-0.951), and examiners (ICC: 0.845-0.950). Pressure pain thresholds applied to the teeth have excellent intra- and inter-examiner agreement in healthy participants. This method may be proposed as an easy and reliable technique to assess mechanical pain sensitivity (e.g. mechanical allodynia and hyperalgesia) in the periodontal ligament, which is associated with endodontic or periodontal conditions.