BACKGROUND: Pain sensitivity is the main finding of central sensitization (CS) and can occur in patients with chronic shoulder pain. However, there is limited evidence concerning the distribution of pain sensitivity in shoulders, forearms, and legs in patients with CS associated with chronic shoulder pain. The present study aimed to determine the distribution of pain sensitivity in patients with CS associated with chronic subacromial pain syndrome (SPS).
METHODS: This cross-sectional study included 58 patients with chronic SPS and CS (patient group) and 58 healthy participants (control group). The presence of CS was determined using the Central Sensitization Inventory (CSI). To determine the distribution of pain sensitivity, pressure pain threshold (PPT) measurements were performed from the shoulders, forearms, and legs.
RESULTS: There was no significant difference between the two groups in terms of sociodemographic data (p > 0.05). The patient group had a significantly higher CSI score (p < 0.001) and lower PPTs in all regions (p < 0.05) than the control group. Unlike the control group, the patient group had lower PPTs on the affected side for the shoulder [mean difference (MD) 95% confidence interval (CI): 1.2 (-1.7 to -0.6)], forearm [MD 95% CI: 1.1 (-1.7 to -0.6)], and leg [MD 95% CI: 0.9 (-1.4 to -0.3)] compared with the contralateral side (p < 0.001).
CONCLUSIONS: Pain sensitivity is more pronounced in the affected shoulder and the forearm and leg located on this side than in those on the contralateral side in patients with CS associated with chronic SPS.

UNASSIGNED: 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.
UNASSIGNED: This study will be a prospective 1:1 allocation, parallel group active controlled trail conducted at Physiotherapy Department, Galgotias University. The trial was prospectively registered with the 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. A total of 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.
UNASSIGNED: The data obtained will be analyzed using appropriate statistical methods, and the significance level will be set at p<0.05.
UNASSIGNED: 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: Exercise induces a hypoalgesic response and improves affect. However, some individuals are unable to exercise for various reasons. Motor imagery, involving kinesthetic and visual imagery without physical movement, activates brain regions associated with these benefits and could be an alternative for those unable to exercise. Virtual reality also enhances motor imagery performance because of its illusion and embodiment. Therefore, we examined the effects of motor imagery combined with virtual reality on pain sensitivity and affect in healthy individuals.
METHODS: Randomized crossover study.
METHODS: Laboratory.
METHODS: Thirty-six participants (women: 18) were included.
METHODS: Each participant completed three 10-min experimental sessions, comprising actual exercise, motor imagery only, and motor imagery combined with virtual reality. Hypoalgesic responses and affective improvement were assessed using the pressure-pain threshold and the Positive and Negative Affect Schedule, respectively.
RESULTS: All interventions significantly increased the pressure-pain threshold at the thigh (P<0.001). Motor imagery combined with virtual reality increased the pressure-pain threshold more than motor imagery alone, but the threshold was similar to that of actual exercise (both P≥0.05). All interventions significantly decreased the negative affect of the Positive and Negative Affect Schedule (all P<0.05).
CONCLUSIONS: Motor imagery combined with virtual reality exerted hypoalgesic and affective-improvement effects similar to those of actual exercise.

OBJECTIVE: The aims of the current study were to investigate the presence of widespread pressure hyperalgesia, the presence of structural changes in the wrist extensor tendon and muscle, and their association in people with lateral epicondylalgia (LE).
METHODS: Thirty-seven patients with LE (43% women; mean age = 45.5 [SD = 9.5] years) and 37 controls matched for age and sex and free of pain participated in this study. Pressure pain thresholds (PPTs) were assessed bilaterally over the symptomatic area (elbow), 2 segment-related areas (C5-C6 joint, second intermetacarpal space), and 1 remote area (tibialis anterior) in a blinded design. Ultrasound measurements (eg, cross-sectional area, thickness, width) of the common wrist extensor tendon and extensor carpi radials brevis muscle as well as thickness of supinator muscle were assessed.
RESULTS: Patients with LE exhibited lower PPTs bilaterally at all points and lower PPTs at the lateral epicondyle and second intermetacarpal space at the symptomatic side as compared to the nonsymptomatic side (η2 from 0.123-0.369; large effects). Patients exhibited higher cross-sectional area and width of the common wrist extensor tendon (η2 from 0.268-0.311; large effects) than controls bilaterally, whereas tendon thickness was also higher (η2 = 0.039; small effects) on the painful side than on the nonpainful side.
CONCLUSIONS: This study reported bilateral widespread pressure pain hyperalgesia and morphological changes in the tendon, but not the muscle, in LE. Pressure pain sensitivity and morphological changes were not associated in individuals with LE.
UNASSIGNED: Management of LE should consider altered nociceptive pain processing and structural tendon changes as 2 different phenomena in patients with LE.

OBJECTIVE: Individuals with chronic pain due to knee osteoarthritis (OA) are insufficiently physically active, and alterations of facilitatory and inhibitory nociceptive signaling are common in this population. Our objective was to examine the association of these alterations in nociceptive signaling with objective accelerometer-based measures of physical activity in a large observational cohort.
METHODS: We used data from the Multicenter Osteoarthritis Study. Measures of peripheral and central pain sensitivity included pressure pain threshold at the knee and mechanical temporal summation at the wrist, respectively. The presence of descending pain inhibition was assessed by conditioned pain modulation (CPM). Physical activity was quantitatively assessed over 7 days using a lower back-worn activity monitor. Summary metrics included steps/day, activity intensity, and sedentary time. Linear regression analyses were used to evaluate the association of pain sensitivity and the presence of descending pain inhibition with physical activity measures.
RESULTS: Data from 1873 participants was analyzed (55.9% female, age = 62.8 ± 10.0 years). People having greater peripheral and central sensitivity showed lower step counts. CPM was not significantly related to any of the physical activity measures, and none of the exposures were significantly related to sedentary time.
CONCLUSIONS: In this cohort, greater peripheral and central sensitivity were associated with reduced levels of objectively-assessed daily step counts. Further research may investigate ways to modify or treat heightened pain sensitivity as a means to increase physical activity in older adults with knee OA.

BACKGROUND: Neck reflex points or Adler-Langer points are commonly used in neural therapy to detect so-called interference fields. Chronic irritations or inflammations in the sinuses, teeth, tonsils, or ears are supposed to induce tension and tenderness of the soft tissues and short muscles in the upper cervical spine. The individual treatment strategy is based on the results of diagnostic Adler-Langer point palpation. This study investigated the inter- and intra-rater reliability and explored treatment effects.
METHODS: We performed a randomized controlled trial with 104 inpatients (80.8% female, 51.8 ± 12.74 years) of a German department for internal and integrative medicine. Patients were randomized to individual neural therapy according to the pathological findings (n = 48) or no treatment (n = 56). In each patient, three experienced raters (20-45 years of experience in neural therapy) and two novice raters (medical students) rated Adler-Langer points rigidity on a standardized rating scale (\"strong,\" \"weak,\" \"none\"). The patients independently evaluated the tenderness on palpation of the eight points using the same scale. Pressure pain thresholds were assessed at the eight Adler-Langer points. All patients were retested after 30 min. The five raters were blinded to treatment allocation and assessments of the other raters. Video recordings were obtained to assess the consistency of the areas tested by the different raters.
RESULTS: Agreement between patients and raters (Cohen\'s kappa = 0.161-0.400) and inter-rater reliability were low (Fleiss kappa = 0.132-0.150). Moreover, the individual agreement (pre-post comparisons in untreated patients) was similarly low even in experienced raters (Cohen\'s kappa = 0.099-0.173). Video documentation suggests that raters do not place their fingers in the correct segments (percentage of correct position: 42.0-60.6%). Pressure pain thresholds at five of the eight Adler-Langer points showed significant changes after treatment compared to none in the control group.
CONCLUSIONS: Under this artificial experimental setting, this method of Adler-Langer point palpation has not proven to be a reliable diagnostic tool. But it could be shown that, as claimed by the method, the tenderness in five of eight Adler-Langer points decreased after neural therapy.
Nackenreflexpunkte oder Adler-Langer-Punkte werden in der Neuraltherapie häufig zum Aufspüren sogenannter Störfelder eingesetzt. Chronische Reizungen oder Entzündungen im Bereich der Nasennebenhöhlen, der Zähne, der Mandeln oder der Ohren sollen zu Verspannungen der kurzen Muskeln sowie zu gesteigerter Druckdolenz des Bindegewebes im Bereich der oberen Halswirbelsäule führen. Die individuelle Behandlungsstrategie richtet sich nach den Ergebnissen der diagnostischen Palpation der Adler-Langer-Punkte. Diese Studie untersuchte die Inter- und Intra-Rater-Reliabilität sowie die Behandlungseffekte. Wir führten eine randomisiert-kontrollierte Studie mit 104 stationären Patienten (80.8% weiblich, 51.8 ± 12.74 Jahre) einer deutschen Abteilung für Innere und Integrative Medizin durch. Die Patienten wurden randomisiert einer individuellen Neuraltherapie entsprechend dem pathologischen Befund (n = 48) oder keiner Behandlung (n = 56) zugewiesen. Bei jedem Patienten bewerteten drei erfahrene Ärzte (20–45 Jahre Erfahrung in der Neuraltherapie) und zwei unerfahrene Untersucher (Medizinstudenten) die Rigidität der Adler-Langer-Punkte auf einer standardisierten Bewertungsskala (“stark,” “schwach,” “keine”). Die Patienten bewerteten ebenfalls die Schmerzempfindlichkeit bei der Palpation der acht Punkte anhand derselben Skala. Die Druckschmerzschwellen wurden an den acht Adler-Langer-Punkten ermittelt. Alle Patienten wurden nach 30 minuten erneut getestet. Die fünf Untersucher waren gegenüber der Behandlungszuweisung und den Bewertungen der anderen Untersucher verblindet. Es wurden Videoaufzeichnungen angefertigt, um die Korrektheit der von den verschiedenen Untersuchern getesteten Bereiche zu bewerten. Die Übereinstimmung zwischen Patienten und Untersuchern (Cohen’s Kappa = 0.161–0.400) und die Zuverlässigkeit zwischen den Untersuchern waren gering (Fleiss-Kappa = 0.132–0.150). Darüber hinaus war die individuelle Übereinstimmung (Prä-Post-Vergleiche bei unbehandelten Patienten) selbst bei erfahrenen Beurteilern ähnlich gering (Cohen’s Kappa = 0.099–0.173). Die Videodokumentation deutet darauf hin, dass die Untersucher ihre Finger nicht in den richtigen Segmenten platzieren (Prozentsatz der korrekten Position 42.0–60.6%). Die Druckschmerzschwellen an fünf der acht Adler-Langer-Punkte wiesen nach der Behandlung signifikante Veränderungen auf, in der unbehandelten Kontrollgruppe dagegen nicht. Unter diesen artifiziellen experimentellen Bedingungen hat sich die Methode der Palpation der Adler-Langer-Punkte nicht als zuverlässiges diagnostisches Instrument erwiesen. Es konnte jedoch gezeigt werden, dass, wie von der Methode behauptet, die Druckdolenz in fünf von acht Adler-Langer-Punkten nach der Neuraltherapie abnahm.

BACKGROUND: Central and peripheral sensitization are characterized by widespread hyperalgesia that is manifested by larger pain extent area and reduction in pressure pain threshold (PPT). PPT decreases in patients with migraine not only over the trigeminal cervical complex but also throughout the body.
METHODS: A cross-sectional study was adopted to assess the local and widespread hyperalgesia in chronic and episodic migraine patients respect to healthy controls. The guidelines of Andersen\'s were used to evaluate the PPT bilaterally over 3 muscles in the trigemino-cervical complex (temporalis, sub-occipitalis, trapezius) and over 1 muscle far from this area (tensor fasciae latae).
RESULTS: Thirty subjects with episodic migraine (35.8 ± 2.82 years), 30 with chronic migraine (53.03 ± 19.79 years), and 30 healthy controls (29.06 ± 14.03 years) were enrolled. The interaction effect was present for the trapezius muscle with a significant difference between the right and the left side in episodic group (p = 0.003). A group effect was highlighted in all four muscles analyzed such as suboccipital (p < 0.001), temporalis (p > 0.001), trapezius (p < 0.001), and TFL (p < 0.001). PPT was usually higher in the control group than in the episodic group which in turn was characterized by higher PPT values than the chronic group.
CONCLUSIONS: People with chronic and episodic migraine presented lower PPT than healthy controls both in the trigeminal and in the extra-trigeminal area. People with chronic migraine presented lower PPT than episodic migraine only in the trigeminal area. Temporalis and sub-occipitalis are the most sensitive muscles in people with chronic and episodic migraine.

Transcutaneous electrical nerve stimulation (TENS) effectively reduces pain in fibromyalgia (FM). The purpose of this study was to examine the influence of TENS use on pressure pain thresholds (PPT) and conditioned pain modulation (CPM) in individuals with FM using data from the Fibromyalgia Activity Study with TENS trial (NCT01888640). Individuals with FM were randomly assigned to receive active TENS, placebo TENS, or no TENS for 4 weeks. A total of 238 females satisfied the per-protocol analysis among the active TENS (n = 76), placebo TENS (n = 68), and no TENS (n = 94) groups. Following 4 weeks of group allocation, the active TENS group continued for an additional 4 weeks of active TENS totaling 8 weeks (n = 66), the placebo and no TENS groups transitioned to receive 4 weeks of active TENS (delayed TENS, n = 161). Assessment of resting pain, movement-evoked pain (MEP), PPT, and CPM occurred prior to and following active, placebo, or no TENS. There were no significant changes in PPT or CPM among the active TENS, placebo TENS, or no TENS groups after 4 weeks. Individuals who reported clinically relevant improvements in MEP (≥30% decrease) demonstrated increases in PPT (P < .001), but not CPM, when compared to MEP non-responders. There were no significant correlations among the change in PPT or CPM compared to MEP and resting pain following active TENS use (active TENS + delayed TENS). PPT and CPM may provide insight to underlying mechanisms contributing to pain; however, these measures may not relate to self-reported pain symptoms. PERSPECTIVE: Pressure pain threshold increased in individuals with clinically relevant improvement (≥30%) in MEP, indicating the clinical relevance of PPT for understanding mechanisms contributing to pain. CPM was not a reliable indicator of treatment response in MEP responders.

UNASSIGNED: We evaluate the presence of sensitization-associated symptoms and neuropathic pain features and identify if there is an association between these symptoms and pressure pain sensitivity, pain, and related-disability in lateral elbow tendinopathy.
UNASSIGNED: Thirty-seven (43% women, age: 45.5 ± 9.5 years) patients with lateral elbow tendinopathy completed: demographic (i.e. age, height, and weight); clinical (i.e. pain history, pain intensity, and Disabilities of the Arm, Shoulder and Hand); and psychophysical (i.e. pressure pain thresholds at the elbow, cervical spine, hand, and leg) outcomes, and the Central Sensitization Inventory and Self-administered Leeds Assessment of Neuropathic Symptoms and Signs questionnaires. Step-wise multiple linear regression models were performed to identify predictors of sensitization- or neuropathic-associated symptoms.
UNASSIGNED: Six (16%) patients exhibited sensitization-associated symptoms (mean: 46.5, SD: 6.1), whereas 13 (35%) patients showed neuropathic-associated symptoms (mean: 13.5; SD: 1.4). Sensitization-associated symptoms were positively associated with neuropathic-associated symptoms (r = 0.538, P = .001) and negatively associated with pressure pain thresholds at the leg (r = -0.378, P = .021). Neuropathic-associated symptoms were positively associated with related-disability (r = 0.479, P = .003) and negatively associated with pressure pain threshold at the elbow (r = -0.394, P = .017). Stepwise regression analyses revealed that neuropathic-like symptoms explained 26.8% of the variance of sensitization symptoms (r2: 0.268), whereas pressure pain threshold at the elbow explained an additional 6.6% to neuropathic-like symptoms (r2: 0.334).
UNASSIGNED: This explorative study identified sensitization- and neuropathic-associated symptoms in 16% and 35% of the people with lateral elbow tendinopathy. Sensitization- and neuropathic-associated symptoms were associated. Pressure pain sensitivity at the elbow (peripheral sensitization) was associated with neuropathic -associated symptoms.

Some authors have proposed the potential role of the radial nerve in lateral epicondylalgia. The aims of this study were to investigate the presence of pressure pain hyperalgesia and nerve swelling (increased cross-sectional area) assessed with ultrasound imaging on the radial nerve in people with lateral epicondylalgia, and to investigate if an association exists between pressure pain sensitivity and cross-sectional area. A total of 37 patients with lateral epicondylalgia (43% women, age: 45.5 ± 9.5 years) and 37 age- and sex-matched pain-free controls were recruited for participation. Pressure pain thresholds (PPTs) were assessed bilaterally on the radial nerve at the spiral groove, the arcade of Frohse, and the anatomic snuffbox in a blinded design. Further, the cross-sectional area of the radial nerve at the spiral groove and antecubital fossa was also assessed. The results demonstrated lower PPTs on the radial nerve of the affected side in individuals with lateral epicondylalgia as compared with the unaffected side (p < 0.01) and with both sides in healthy controls (p < 0.001). Additionally, the cross-sectional area of the radial nerve on the affected side in patients was higher compared with the unaffected side (p < 0.01) and both sides in healthy controls (p < 0.001). The cross-sectional area of the radial nerve at the spiral groove was negatively associated with PPTs over the radial nerve at the spiral groove (r = -0.496, p = 0.002) and positively associated with function (r = 0.325, p = 0.045). Our findings revealed generalized pressure pain hyperalgesia and also nerve swelling of the radial nerve in people with lateral epicondylalgia, suggesting the presence of a widespread sensitization of nerve tissues in this population. The radial nerve could represent a potential peripheral drive to initial and maintain altered pain processing in lateral epicondylalgia.