Pressure pain thresholds of tender point sites in patients with fibromyalgia and in healthy controls

Individuals with fibromyalgia report greater pain sensitivity than healthy adults while listening to their favorite music: the contribution of negative affect

OBJECTIVE

We investigated the impact of favorite music on pain processing among individuals with fibromyalgia. We also examined differences in pain processing between individuals with fibromyalgia and healthy controls (HC) while listening to favorite music and explored whether psychosocial factors contributed to these differences.

METHODS

Individuals with fibromyalgia and HC completed baseline psychosocial questionnaires and then underwent quantitative sensory testing (QST) during 3 randomized music conditions (meditative music, favorite music, white noise). Among individuals with fibromyalgia, Friedman tests were used to investigate differences in QST across conditions. Analyses of Covariance were used to examine group (HC vs fibromyalgia) differences in QST during favorite music. Correlations were conducted to explore associations of baseline psychosocial factors with QST during favorite music. Mediation analyses were conducted to explore whether psychosocial factors contributed to greater pain sensitivity among individuals with fibromyalgia compared to HC during favorite music.

RESULTS

Individuals with fibromyalgia were less sensitive to pressure pain while listening to their favorite music compared to white noise. Compared to HC, individuals with fibromyalgia reported higher baseline negative affect and lower pain thresholds and tolerances during favorite music. Negative affect partially mediated the relationship between pain status (HC vs fibromyalgia) and pain sensitivity during favorite music.

CONCLUSIONS

Individuals with fibromyalgia were less pain sensitive while listening to favorite music than white noise, although they were more sensitive than HC. Greater negative affect endorsed by individuals with fibromyalgia contributed to their greater pain sensitivity. Future studies should explore the impact of favorite music on clinical pain.

CLINICAL TRAILS REGISTRATION

This study was registered with ClinicalTrials.gov (NCT04087564) and began on 6/13/2019.

Mechanisms and Preventative Strategies for Persistent Pain following Knee and Hip Joint Replacement Surgery: A Narrative Review

Chronic postsurgical pain (CPSP) following total knee arthroplasty (TKA) and total hip arthroplasty (THA) is a prevalent complication of joint replacement surgery which has the potential to decrease patient satisfaction, increase financial burden, and lead to long-term disability. The identification of risk factors for CPSP following TKA and THA is challenging but essential for targeted preventative therapy. Recent meta-analyses and individual studies highlight associations between elevated state anxiety, depression scores, preoperative pain, diabetes, sleep disturbances, and various other factors with an increased risk of CPSP, with differences observed in prevalence between TKA and THA. While the etiology of CPSP is not fully understood, several factors such as chronic inflammation and preoperative central sensitization have been identified. Other potential mechanisms include genetic factors (e.g., catechol-O-methyltransferase (COMT) and potassium inwardly rectifying channel subfamily J member 6 (KCNJ6) genes), lipid markers, and psychological risk factors (anxiety and depression). With regards to therapeutics and prevention, multimodal pharmacological analgesia, emphasizing nonopioid analgesics like acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs), has gained prominence over epidural analgesia. Nerve blocks and local infiltrative anesthesia have shown mixed results in preventing CPSP. Ketamine, an N-methyl-D-aspartate (NMDA)-receptor antagonist, exhibits antihyperalgesic properties, but its efficacy in reducing CPSP is inconclusive. Lidocaine, an amide-type local anesthetic, shows tentative positive effects on CPSP. Selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs) have mixed results, while gabapentinoids, like gabapentin and pregabalin, present hopeful data but require further research, especially in the context of TKA and THA, to justify their use for CPSP prevention.

Immediate and Short-Term Effects of In-Shoe Heel-Lift Orthoses on Clinical and Biomechanical Outcomes in Patients With Insertional Achilles Tendinopathy

Background

Physical therapists frequently employ heel lifts as an intervention to reduce Achilles tendon pain and restore function.

Purpose

To determine the short-term effect of heel lifts on clinical and gait outcomes in participants with insertional Achilles tendinopathy (IAT).

Study Design

Case series; Level of evidence, 4.

Methods

Participants with IAT underwent eligibility screening and completed assessments at baseline and 2 weeks later. Primary outcomes included symptom severity (Victoria Institute of Sports Assessment-Achilles [VISA-A]), gait analysis with the 10-m walk-test at 2 speeds (normal and fast), and pain during walking. Pain and gait analysis were assessed under 3 conditions: before fitting 20-mm heel lifts, immediately after heel-lift fitting, and after 2 weeks of wearing heel lifts. Ultrasound images and measurements at the Achilles insertion were obtained from prone and standing positions (with and without heel lifts). Spatiotemporal gait parameters and tibial tilt angles were evaluated at normal speed using inertia measurement units during the 3 study conditions. Differences between the conditions were analyzed using paired t test or analysis of variance.

Results

Overall, 20 participants (12 female, 13 with bilateral IAT; mean age, 51 ± 9.3 years; mean body mass index 31.6 ± 6.8 kg/m2) completed all assessments. Symptom severity (VISA-A) of the more symptomatic side significantly improved at 2 weeks (60 ± 20.6) compared with baseline (52.2 ± 20.4; P < .01). Pain during gait (Numeric Pain Rating Scale) was significantly reduced immediately after heel-lift fitting (0.7 ± 2.0) when compared with baseline (2.2 ± 2.7, P = .043). Spatiotemporal gait parameters and tibial tilt angle before and after using heel lifts at normal walking speed were not significantly different; however, gait speed, stride length, and tibial tilt angle on both sides increased significantly immediately after using heel lifts and were maintained after 2 weeks of wear.

Conclusion

Using heel lifts not only improved symptom severity after 2 weeks but also immediately reduced pain during gait and had a positive impact on gait pattern and speed.

Comprehensive quantitative sensory testing shows altered sensory function in women with chronic pelvic pain: results from the Translational Research in Pelvic Pain (TRiPP) Study

ABSTRACT

Chronic pelvic pain (CPP), despite its high prevalence, is still relatively poorly understood mechanistically. This study, as part of the Translational Research in Pelvic Pain (TRiPP) project, has used a full quantitative sensory testing (QST) paradigm to profile n = 85 women with and without CPP (endometriosis or bladder pain specifically). We used the foot as a control site and abdomen as the test site. Across 5 diagnostically determined subgroups, we found features which are common across different aetiologies, eg, gain of function in pressure pain threshold (PPT) when assessing responses from the lower abdomen or pelvis (referred pain site). However, disease-specific phenotypes were also identified, eg, greater mechanical allodynia in endometriosis, despite there being large heterogeneities within diagnostic groups. The most common QST sensory phenotype was mechanical hyperalgesia (>50% across all the groups). A "healthy' sensory phenotype was seen in <7% of CPP participants. Specific QST measures correlated with sensory symptoms assessed by the painDETECT questionnaire (pressure-evoked pain [painDETECT] and PPT [QST] [ r = 0.47, P < 0.001]; mechanical hyperalgesia (painDETECT) and mechanical pain sensitivity [MPS from QST] [ r = 0.38, P = 0.009]). The data suggest that participants with CPP are sensitive to both deep tissue and cutaneous inputs, suggesting that central mechanisms may be important in this cohort. We also see phenotypes such as thermal hyperalgesia, which may be the result of peripheral mechanisms, such as irritable nociceptors. This highlights the importance of stratifying patients into clinically meaningful phenotypes, which may have implications for the development of better therapeutic strategies for CPP.

Measurement of pressure discomfort threshold in auricular concha for in-ear wearables design

In an effort to mitigate the homogenization of in-ear wearables, designers have been focusing on finding new solutions to enhance user comfort. While the concept of pressure discomfort thresholds (PDT) in humans has been applied to product design, research on the auricular concha remains scarce. In this study, we conducted an experiment to measure the PDT at six points in the auricular concha of 80 participants. Our results showed that the tragus was the most sensitive area and that gender, symmetry, and Body Mass Index (BMI)had no significant effect on PDT. Based on these findings, we generated pressure sensitivity maps of the auricular concha to aid in the optimization of in-ear wearable design.

In-ear earphone design-oriented pressure sensitivity evaluation on the external ear

This study aimed to explore the pressure sensitivity of the external ear that can be the basis for adapting the pressure distribution on the concha for in-ear earphone design. Overall, 30 participants were included in this study, where an electronic mechanical algometer with a stepping motor was used to apply constant pressure. Before the experiment, the customised concha shell models of the participants were positioned in the ear perpendicular to the concha surface. Furthermore, the pressure discomfort threshold (PDT), moderate pressure discomfort (MPD), and maximum pressure threshold (MPT) in eight regions of the ear were recorded. This study's results indicate that the four regions of the external ear are less sensitive to pressure than those of the other regions. Additionally, women had higher pressure sensitivity values in the external ear. Therefore, this study's findings could have important implications for earphone designs and evaluating discomfort conditions in the external ear. Practitioner summary: This study explores the pressure sensitivity threshold (PDT, MPD, and MPT) on the external ear and the relevant implications for in-ear earphone design. Interestingly, regions closer to the bone structure were less sensitive to pressure, and men could tolerate greater pressure on the external ear than women.

Pain pressure threshold algometry in knee osteoarthritis: intra- and inter-rater reliability

INTRODUCTION

Synovitis and effusion can cause pain sensitization in persons with knee osteoarthritis (KOA). Pain Pressure Threshold (PPT) algometry is a means to quantify somatosensory abnormalities, including inflammatory-mediated pressure hyperalgesia. We investigated the reliability of PPT algometry with three raters.

METHODS

Twenty-seven persons (50 knees) with KOA, according to the American College of Rheumatology criteria, were included. The PPT of the most tender spot in the joint line of each knee, identified by palpation, was assessed using a digital pressure algometer with a round 1 cm² rubber tip. The algometer was applied three times with at least twenty-second intervals by three physiotherapists each in a single session. Two of the physiotherapists had no experience with the procedure prior to the study. We estimated the Intraclass Correlation Coefficient (ICC) model 2.1, 95% within-subject standard deviation (s_w), and Minimal Detectable Difference (MDD).

RESULTS

The mean PPTs ranged from 39.94 to 41.81 Newton (N), the intra-rater ICC ranged from 0.909 to 0.956, the s_w ranged from 6.44 to 10.77 N, and the related MDD ranged from 9.11 to 15.23 N. The three raters achieved an inter-rater ICC of 0.707, an s_w of 17.68 N, and an MDD of 25.01 N. The results were homoscedastic.

CONCLUSIONS

Our results indicate that PPT algometry is a suitable method for assessment of pain in osteoarthritic knees. After a short session of PPT procedure training, good intra-rater and acceptable inter-rater ICCs were achieved.

Effectiveness of Manual Trigger Point Therapy in Patients with Myofascial Trigger Points in the Orofacial Region-A Systematic Review

The objective was to compile, synthetize, and evaluate the quality of the evidence from randomized controlled trials (RCTs) regarding the effectiveness of manual trigger point therapy in the orofacial area in patients with or without orofacial pain. This project was registered in PROSPERO and follows the PRISMA guidelines. Searches (20 April 2021) were conducted in six databases for RCTs involving adults with active or latent myofascial trigger points (mTrPs) in the orofacial area. The data were extracted by two independent assessors. Four studies were included. According to the GRADE approach, the overall quality/certainty of the evidence was very low due to the high risk of bias of the studies included. Manual trigger point therapy showed no clear advantage over other conservative treatments. However, it was found to be an equally effective and safe therapy for individuals with myofascial trigger points in the orofacial region and better than control groups. This systematic review revealed a limited number of RCTs conducted with patients with mTrPs in the orofacial area and the methodological limitations of those RCTs. Rigorous, well-designed RCTs are still needed in this field.

Effects of Intraoperative Opioid Administration on Postoperative Pain and Pain Threshold: A Randomized Controlled Study

Fentanyl and short-acting remifentanil are often used in combination. We evaluated the effect of intraoperative opioid administration on postoperative pain and pain thresholds when the two drugs were used. Patients who underwent gynecological laparoscopic surgery were randomly assigned into two groups (15 patients each) to receive either sufficient (group A) or minimum (group B) fentanyl (maximum estimated effect site concentration: A: 7.86 ng/mL, B: 1.5 ng/mL). The estimated effect site concentration at the end of surgery was adjusted to the same level (1 ng/mL). Patients in both groups also received continuous intravenous remifentanil during surgery. The primary outcome was the pressure pain threshold, as evaluated by a pressure algometer 3 h postoperatively. The pressure pain threshold at 3 h postoperatively was 51.1% (95% CI: [44.4–57.8]) in group A and 56.6% [49.5–63.6] in group B, assuming a preoperative value of 100% (p = 0.298). There were no significant differences in pressure pain threshold and numeric rating scale scores between the groups after surgery. The pain threshold decreased significantly in both groups at 3 h postoperatively compared to preoperative values, and recovered at 24 h. Co-administration of both opioids caused hyperalgesia regardless of fentanyl dose.

Measurement of soft tissue deformation at discomfort and pain threshold in different regions of the head

Understanding of product-soft tissue interface and related discomfort is essential while designing wearable devices. Although pressure thresholds at the perception of discomfort and pain have been measured in the past, associated tissue deformation is yet to be studied. This data can provide a holistic understanding of user discomfort and be a valuable reference for ergonomic product design. Hence, in the current study, tissue deformation at discomfort and pain threshold was measured using an ultrasound indentation device at 18 landmarks for 83 Chinese adults on the head and face. Results show that deformation was higher in the facial region than the scalp and forehead, with maximum deformation in the cheek area and minimum in the forehead region for both thresholds. Also, for most landmarks, the tissue deformation data showed no significant relationship with age and Body Mass Index (BMI). Nearly half of the landmarks exhibited significant gender-based differences. Overall, the measured data showed acceptable within-session and between-session reliability. Practitioner Summary: In this study, tissue deformation was measured in different head regions for discomfort and pain thresholds, and corresponding deformation maps were developed. Measured tissue deformation data showed no significant relationship with BMI and age. This data can be a useful reference in the design, testing, and evaluation of headgears.

Towards the Objective Identification of the Presence of Pain Based on Electroencephalography Signals' Analysis: A Proof-of-Concept

This proof-of-concept study explores the potential of developing objective pain identification based on the analysis of electroencephalography (EEG) signals. Data were collected from participants living with chronic fibromyalgia pain (n = 4) and from healthy volunteers (n = 7) submitted to experimental pain by the application of capsaicin cream (1%) on the right upper trapezius. This data collection was conducted in two parts: (1) baseline measures including pain intensity and EEG signals, with the participant at rest; (2) active measures collected under the execution of a visuo-motor task, including EEG signals and the task performance index. The main measure for the objective identification of the presence of pain was the coefficient of variation of the upper envelope (CVUE) of the EEG signal from left fronto-central (FC5) and left temporal (T7) electrodes, in alpha (8-12 Hz), beta (12-30 Hz) and gamma (30-43 Hz) frequency bands. The task performance index was also calculated. CVUE (%) was compared between groups: those with chronic fibromyalgia pain, healthy volunteers with "No pain" and healthy volunteers with experimentally-induced pain. The identification of the presence of pain was determined by an increased CVUE in beta (CVUE_β) from the EEG signals captured at the left FC5 electrode. More specifically, CVUE_β increased up to 20% in the pain condition at rest. In addition, no correlation was found between CVUE_β and pain intensity or the task performance index. These results support the objective identification of the presence of pain based on the quantification of the coefficient of variation of the upper envelope of the EEG signal.

Effectiveness of Negative Pulsed-Pressure Myofascial Vacuum Therapy and Therapeutic Exercise in Chronic Non-Specific Low Back Pain: A Single-Blind Randomized Controlled Trial

Non-specific low back pain is defined as pain located in the lumbar region; this condition is the most frequent musculoskeletal disorder. Negative pulsed-pressure myofascial vacuum therapy (vacuum treatment (VT)) devices mobilize tissue according to previously programmed parameters of force, time and frequency. The purpose of this study was to compare the effects of VT combined with core therapeutic exercise versus a physical therapy program (PTP) based only on core therapeutic exercise. Fifty participants with chronic non-specific low back pain were randomly assigned to two treatment groups, the VT group (n = 25) or the PTP group (n = 25). Pain, pressure-pain threshold, range of motion, functionality and quality of life were measured before treatment, at the end of treatment, and at one-month and three-month follow-ups. Both groups received 15 therapy sessions over 5 weeks. Statistically significant differences in favor of the VT group were shown in the results. In conclusion, the intervention based on myofascial vacuum therapy improved pain, mobility, pressure pain threshold, functionality and quality of life.

No indications for altered EEG oscillatory activity in patients with chronic post-burn itch compared to healthy controls

A large proportion of patients with burn injuries develop chronic itch, which impacts quality of life. The underlying pathophysiological mechanisms are poorly understood. This cross-sectional pilot study investigates whether altered cortical oscillatory processes are involved in chronic post-burn itch. Continuous electroencephalography (EEG) data were recorded during rest and stimulation of non-injured skin, inducing itch (histamine and electrical) and cold-pressor task pain for 15 adults with chronic post-burn itch and 15 matched healthy controls. Quantitative metrics comprised oscillatory power and peak frequencies in theta, alpha, and beta bands. No statistical differences between patients and healthy controls were found in oscillatory activity during rest or stimulation, with Bayesian analysis suggesting equivocal evidence. However, post-traumatic stress symptoms and duration of chronic itch may be associated with changes in oscillatory activity. A lack of differences in cortical oscillatory processing and itch levels at non-injured sites, suggests that itch symptoms have a localised character in this sample of patients with post-burn itch. For future studies, a biopsychological approach with integration of peripheral and central nervous system techniques, linear and non-linear EEG analysis, injured and non-injured stimulation sites, and incorporation of individual characteristics is recommended. Insight into pathophysiological mechanisms underlying chronic post-burn itch could improve diagnostics and treatments.

Does aerobic exercise effect pain sensitisation in individuals with musculoskeletal pain? A systematic review

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.

Acupuncture-like versus conventional transcutaneous electrical nerve stimulation in the management of active myofascial trigger points: A randomized controlled trial

PURPOSE

Myofascial pain syndrome (MPS) is one of the most common causes of chronic musculoskeletal pain. The transcutaneous electrical nerve stimulation (TENS) is a non-expensive, safe, feasible modality, used recently for the treatment of MPS with promising but limited results. The purpose of this study was to determine the efficacy of acupuncture-like TENS (AL-TENS) vs conventional TENS (C-TENS) in the treatment of active myofascial trigger points.

METHODS

This randomized controlled trial study was carried out with 60 consecutive patients with active trapezius trigger points referred to Physical Medicine and Rehabilitation Clinic. Participants randomly assigned to receive AL-TENS, C-TENS or sham TENS (S-TENS). The Visual Analogue Scale (VAS), Pressure Pain Thresholds (PPTs), and neck range of motion (ROM) were measured at baseline, after the first treatment sessions, after the final treatment session, and 3 months after the end of the last treatment session. Patients function was evaluated by Disabilities of the Arm, Shoulder, and Hand (DASH) at baseline, after the final treatment sessions, and 3 months after the end of intervention.

RESULTS

The interaction effect of time and group was significantly different when evaluating VAS (df = 4.65, F = 2.50, p = 0.038) and DASH (df = 2.63, F = 7.25, p < 0.001) in favor of active groups, as well as neck total lateral bending in favor of AL-TENS group compared other two groups (df = 4.16, F = 5.23, p = 0.001). Both VAS and DASH improved significantly at all follow-ups in AL-TENS and C-TENS groups. Of note, significant immediate improvement in all outcomes was observed only with AL-TENS.

CONCLUSIONS

According to the present study, both AL-TENS and C-TENS were superior to placebo in pain reduction and functional improvement. Although both TENS techniques have similar efficiency on pain reduction, functional and pain perception improvement, the AL-TENS was the superior approach when evaluating neck lateral bending ROM.

Assessment of pressure sensitivity in the head region for Chinese adults

Measurement of pressure threshold has found its applications in the fields of medical sciences and product design. Hence it has been a profound area of research interest for several decades. However, hardly any detailed investigation has been undertaken to measure the pressure threshold in the head region. In this study, Pressure Discomfort Threshold (PDT) and Pressure Pain Threshold (PPT) were measured for two hundred eighteen healthy Chinese adults at seventy-six anatomical locations, and further statistical analyses were performed on the acquired data to understand the relationship between different demographic parameters. The results suggest that the pressure sensitivity is low in the vertex region, moderate in the forehead and temporal area, and high in the facial and nasal region. From this study, pressure sensitivity maps were developed for PDT and PPT for Chinese adults. The measured pressure threshold data showed no significant relationship with age and Body Mass Index (BMI).

Hypoalgesic and Motor Effects of Neural Mobilisation versus Soft-Tissue Interventions in Experimental Craniofacial Hyperalgesia: A Single-Blinded Randomised Controlled Trial

Objective: The present trial aimed to compare the effects of the mobilisation of the nervous system (NS) to those of a soft-tissue intervention in subjects exposed to an experimentally induced hyperalgesia of the masticatory muscles. Methods: The study was a single-blinded randomised controlled trial. A total of 49 participants (mean ± SD age: 41 ± 11 years; 61% female) with latent myofascial trigger points (LMTrPs) in the craniofacial region were randomly assigned to one of three groups: neural mobilisation (NM), soft-tissues techniques and stretching (STT-S), and control group (CG). An initial assessment (baseline) was performed before the provocation chewing masticatory test. The pre-treatment measurements were registered 24 h later. Next, the randomised intervention was applied, and afterwards, post-treatment data were obtained. Outcome measures included pain-free maximum mouth opening (MMO), pressure pain thresholds (PPTs) in the trigeminal and cervical region, and trigeminal and cervical two-point discrimination (TPD). Results: ANOVA revealed significant differences for the time × group interaction for pain-free MMO and PPTs. The results showed an improvement in the MMO and the PPTs for NM and STT-S groups but not for the CG. There were no differences between the NM and STT-S groups. However, the effect sizes were large for the NM and medium for the STT-S. No differences were found for TDP between groups nor over time. Conclusions: The results show that with NM and STT-S techniques, we could influence motor and sensory variables in asymptomatic subjects with LMTrPs after a masticatory provocation test. Both techniques increased MMO and PPTs in the short term. These beneficial effects lead us to consider the importance of including these methods in clinical practice.

Effectiveness of low-level laser therapy and chewing gum in reducing orthodontic pain: A randomized controlled trial

Objective

The purpose of this study was to evaluate the effects of chewing gum and low-level laser therapy in alleviating orthodontic pain induced by the initial archwire.

Methods

Patients with 3–6 mm maxillary crowding who planned to receive non-extraction orthodontic treatment were recruited for the study. Sixty-three participants (33 females and 30 males) were randomly allocated into three groups laser, chewing gum, and control. In the laser group, a gallium aluminum arsenide (GaAlAs) diode laser with a wavelength of 820 nm was used to apply a single dose immediately after orthodontic treatment began. In the chewing gum group, sugar-free gum was chewed three times for 20 minutes—immediately after starting treatment, and at the twenty-fourth and forty-eighth hours of treatment. Pain perception was measured using a visual analog scale at the second, sixth, and twenty-fourth hours, and on the second, third, and seventh days.

Results

There were no statistically significant differences between the groups at any measured time point (p > 0.05). The highest pain scores were detected at the twenty-fourth hour of treatment in all groups.

Conclusions

Within the limitations of the study, we could not detect whether low-level laser therapy and chewing gum had any clinically significant effect on orthodontic pain. Different results may be obtained with a higher number of participants or using lasers with different wavelengths and specifications. Although the study had a sufficient number of participants according to statistical analysis, higher number of participants could have provided more definitive outcomes.

Conditioned pain modulation and pain sensitivity in functional somatic disorders: The DanFunD study

Background

Disrupted pain regulation has been proposed as a component in functional somatic disorders (FSD). The objective of this study was to examine a general population sample, encompassing three delimitations of FSD while assessing pain sensitivity and conditioning pain modulation (CPM).

Methods

Pressure pain thresholds (PPTs) at the tibialis and trapezius muscles were recorded at baseline. During cold pressor stimulation of the hand, the tibialis PPTs were re‐assessed and the difference from baseline measures defined the CPM effect. Participants (n = 2,198, 53% females) were randomly selected from the adult Danish population. FSD was established by self‐reported symptom questionnaires.

Results

With a few exceptions, only weak associations were seen between PPTs and CPM in cases with FSD (p > .1). A high PPT was associated with lower odds of having multi‐organ bodily distress syndrome (OR^{PPT trapezius}: 0.66, 95% CI: 0.49–0.88, p = .005), with the symptom profile characterized by all symptoms (OR^{PPT trapezius}: 0.72, 95% CI: 0.58–0.90, p = .003 and OR^{PPT tibialis}: 0.75, 95% CI: 0.62–0.91, p = .004), and with multiple chemical sensitivity (OR^{PPT trapezius}: 0.81, 95% CI: 0.67–0.97, p = .022). High CPM was associated with high odds of having irritable bowel (OR^{CPM relative}: 1.22, 95% CI: 1.04–1.43, p = .013 and OR^{CPM absolute} = 2.66, 95% CI: 1.07–6.45, p = .033).

Conclusion

However, only PPT measured over the trapezius muscle were still significant after correction for multiple testing for the symptom profile characterized by all symptoms. Findings from this study do not support altered pain regulation in questionnaire‐based FSD which is in contrast with the existing presumption. Further epidemiological studies in this field are needed.

Significance

Disrupted pain regulation as measured by abnormal pain thresholds has been hypothesized as a central mechanism in Functional Somatic Disorders (FSD). The hypothesis has been raised in clinical setting where patients presented subjective and objective features of hypersensitivity. The present population‐based study does not support this notion. This points to the importance of further studies into the underlying pathophysiology mechanisms of FSD.

Hyperalgesia and Central Sensitization in Subjects With Chronic Orofacial Pain: Analysis of Pain Thresholds and EEG Biomarkers

Introduction: The presence of a temporomandibular disorder is one of the most frequent causes of orofacial pain (OFP). When pain continues beyond tissue healing time, it becomes chronic and may be caused, among other factors, by the sensitization of higher-order neurons. The aim of this study is to describe psychological characteristics of patients with chronic OFP, their peripheral pain threshold, and electroencephalography (EEG) recording, looking for possible signs of central sensitization (CS). Materials and methods: Twenty-four subjects with chronic OFP caused by temporomandibular disorder were evaluated using the Research Diagnostic Criteria for Temporomandibular Disorders Axis I and Axis II. Pain intensity, catastrophizing, and presence of CS were assessed through self-reported questionnaires. Pressure pain threshold (PPT) was recorded in facial and peripheral sites; EEG activity was recorded during open and closed eyes resting state and also during the pain threshold assessment. Pain thresholds and EEG recordings were compared with a cohort of pain-free age- and sex-matched healthy subjects. Results: Patients with chronic OFP showed a significant reduction in their pain threshold compared to healthy subjects in all sites assessed. Greater reduction in pain threshold was recorded in patients with more severe psychological symptoms. Decreased alpha and increased gamma activity was recorded in central and frontal regions of all subjects, although no significant differences were observed between groups. Discussion: A general reduction in PPT was recorded in people who suffer from chronic OFP. This result may be explained by sensitization of the central nervous system due to chronic pain conditions. Abnormal EEG activity was recorded during painful stimulation compared to the relaxed condition in both chronic OFP subjects and healthy controls.

Comparison of dry needling and trigger point manual therapy in patients with neck and upper back myofascial pain syndrome: a systematic review and meta-analysis

BACKGROUND

Patients with myofascial pain syndrome of the neck and upper back have active trigger points and may present with pain and decreased function. Dry needling (DN) and trigger point manual therapy (TMPT) techniques are often used to manage MPS.

OBJECTIVE

To compare DN and TPMT for reducing pain on the Visual Analog Scale (VAS) and Pressure Pain Threshold (PPT) scores and improving function on the Neck Disability Index (NDI) in patients with neck and upper back MPS.

METHODS

PubMed, PEDro, and CINAHL were searched for randomized controlled trials within the last 10 years comparing a group receiving DN and the other receiving TPMT. Studies were assessed using PEDro scale and Cochrane risk-of-bias tool to assess methodological quality. Meta-analyses were performed using random-effect model. Standardized mean differences (Cohen's d) and confidence intervals were calculated to compare DN to TPMT for effects on VAS, PPT, and NDI.

RESULTS

Six randomized controlled trials with 241 participants total were included in this systematic review. The effect size of difference between DN and TPMT was non-significant for VAS [d = 0.41 (-0.18, 0.99)], for PPT [d = 0.64 (-0.19, 1.47)], and for NDI [d = -0.66 (-1.33, 0.02)].

CONCLUSIONS

Both DN and TPMT improve pain and function in the short to medium term. Neither is more superior than the other.

Intramuscular Pressure Is Almost Three Times Higher in Fibromyalgia Patients: A Possible Mechanism for Understanding the Muscle Pain and Tenderness

OBJECTIVE

Widespread pain in fibromyalgia syndrome (FMS) is conventionally viewed as arising from disordered central processing. This study examines intramuscular pressure in the trapezius as an alternative mechanism for understanding FMS pain.

METHODS

One hundred eight patients who satisfied the American College of Rheumatology criteria for FMS and 30 patients who met the ACR criteria for another rheumatic disease comprised the study groups. Muscle pressure was measured in mmHg using a pressure gauge attached to a no. 22 needle inserted into the mid-portion of the trapezius muscle. In addition, patients with FMS and rheumatic disease controls had dolorimetry testing, digital palpation, and reported pain scores.

RESULTS

Muscle pressure was substantially higher in patients with FMS with a mean value of 33.48 ± 5.90 mmHg. Only 2 of 108 patients had muscle pressure of < 23 mmHg. The mean pressure in rheumatic disease controls was 12.23 ± 3.75 mmHg, with a range from 3-22 mmHg. Patients with FMS were more tender than controls based on both dolorimetry (P < 0.001) and digital palpation (P < 0.001). The mean pain score in patients with FMS and controls was 6.68 ± 1.91 and 1.43 ± 1.79, respectively (P < 0.001).

CONCLUSION

Pressure in the trapezius muscle of patients with FMS is remarkably elevated and may be an intrinsic feature of FMS that could be monitored as part of the diagnostic evaluation. The burden of the pressure abnormality may help explain the diffuse muscle pain of FMS. Therefore, FMS as a disorder of exclusively central pain processing should be revisited. Therapeutically, the reduction of muscle pressure may change the clinical picture significantly.

Hyperalgesia and Central Sensitization Signs in Patients with Cluster Headache: A Cross-Sectional Study

OBJECTIVE

To investigate central sensitization (CS) in cluster headache (CH) and to evaluate its relationship with disease characteristics and psychological comorbidities.

DESIGN

Cross-sectional study.

SETTINGS

Whether CS occurs in CH, as it does in other primary headaches, is a subject of debate. Few studies have evaluated the presence of CS and its relationship with psychological comorbidities in patients with CH.

SUBJECTS

Twenty patients with episodic or chronic CH and 16 healthy controls were recruited.

METHODS

The variables evaluated included frequency, intensity and duration of headache attacks, pressure pain thresholds (PPTs) and wind-up (WU) ratios of pain bilaterally measured over trigeminal and extratrigeminal areas, and results of questionnaires regarding anxiety and depression (Hospital Anxiety and Depression Scale [HADS], Beck Depression Inventory [BDI], State-Trait Anxiety Inventory [STAI]), quality of life (Short Form-36 [SF-36]), headache impact (Headache Impact Test [HIT-6]), and allodynia (Allodynia Symptom Checklist [ASC]).

RESULTS

PPT levels were significantly lower in the CH group compared with the healthy participants (all tested points, P < 0.001). No differences were found in WU ratios between groups. However, differences in HADS (P < 0.01), BDI (P < 0.01), STAI (P < 0.01), SF-36 (P < 0.01), HIT-6 (P < 0.001), and ASC (P < 0.01) were observed between groups. The healthy group showed a moderate negative correlation between SF-36 and BDI (rho = -0.59, P = 0.03). Likewise, the CH group showed a moderate negative correlation between frequency and BDI (rho = -0.52, P = 0.03), a strong positive correlation between duration and HADS (rho = 0.86, P < 0.01), and a moderate negative correlation between intensity and PPT over symptomatic V1 (rho = -0.66, P < 0.01) and over asymptomatic V1 (rho = -0.65, P < 0.01). The CH group also showed a moderate negative correlation between SF-36 and anxiety and depression variables.

CONCLUSIONS

Our findings show that patients with CH have lower PPT levels at cranial and extracranial points, suggesting, as in other primary headaches, the presence of CS. We have also found a high prevalence of psychiatric comorbidities that correlate with the length and frequency of attacks. These findings highlight the importance of a multidisciplinary approach to the treatment of patients with CH.

Is hypovitaminosis D associated with fibromyalgia? A systematic review

CONTEXT

Recent findings have suggested a high prevalence of vitamin D deficiency or insufficiency in fibromyalgia (FM) patients despite the lack of clinical and pathophysiological evidence.

OBJECTIVE

A systematic review was conducted to examine the association between vitamin D status and FM, including the effect of vitamin D supplementation.

DATA SOURCE

PubMed, LILACS, Scopus, SciELO, Cochrane, and EMBASE were searched, from January 2000 to July 2018, using the descriptors "Fibromyalgia" and "Vitamin D."

STUDY SELECTION

Trials including FM patients in whom vitamin D levels were assessed were eligible for inclusion.

DATA EXTRACTION

Data comprised age, gender, country, aims, bias, diagnosis criteria, cutoff point, and status of vitamin D, together with FM symptoms and vitamin D supplementation protocol.

RESULTS

A total of 26 articles were selected. Most of the studies were found to present unreliable control groups and small samples. Experimental data on vitamin D supplementation indicated improvement in certain FM symptoms.

CONCLUSION

Prevalence of hypovitaminosis D in the FM population and the cause-effect relationship were inconclusive. Nevertheless, vitamin D supplementation may be considered as a co-adjuvant in FM therapy.

Acupuncture for primary fibromyalgia: Study protocol of a randomized controlled trial

Background

Acupuncture is well recognized for its unique therapeutic effect for many diseases as a nonpharmacological therapy in traditional Chinese medicine (TCM). However, whether acupuncture can effectively treat fibromyalgia is currently unclear. Therefore, we aim to design a study protocol of a randomized controlled clinical trial and assess the effectiveness of acupuncture for patients with fibromyalgia, which may lead to alleviation of clinical symptoms and improvement of patients’ quality of life.

Methods

The study is designed as a randomized, blinded, placebo-controlled trial of two cohorts conducted at Guang’anmen Hospital of China Academy of Chinese Medical Sciences and Shenzhen Traditional Chinese Medicine Hospital, respectively. A total of 68 patients with primary fibromyalgia, diagnosed with the American College of Rheumatology criteria, are randomly allocated with a 1:1 ratio to acupuncture or sham acupuncture groups. All subjects will receive acupuncture intervention for 8 weeks with follow-up assessments every 4 weeks for 16 weeks. The primary outcome will be evaluated using the visual analogue scale (VAS) and revised fibromyalgia impact questionnaire (FIQR) for pain intensity. The secondary outcome measures will include: Multidimensional Assessment of Fatigue scale (MAF), Short Form-36 (SF-36), Beck Depression Inventory (BDI), Pittsburgh Sleep Quality Index (PSQI), Chinese perceived stress scales (pss-14), changes in the number of 18 tender points, patient satisfaction for the treatment and adverse events. The mentioned outcome measurements will be assessed every 4 weeks for 6 months.

Discussion

This clinical trial will use advanced research methods to evaluate the efficacy and safety of acupuncture on fibromyalgia. The results of this trial may provide clinical evidence on the beneficial effects of acupuncture in treating fibromyalgia.

Trial registration

Chinese Clinical Trial Registry, ChiCTR1800016826: AMCTR-IOR-18000184. Registered 27 June 2018, http://www.acmctr.org/listbycreater.aspx

The effect of alexithymia and depressive feelings on pain perception in somatoform pain disorder

OBJECTIVE

To investigate the relationship between alexithymia and depression and their influence on the subjective versus experimental pain perception in somatoform pain disorder.

METHODS

Three groups consisting of 40 patients with somatoform pain disorder, 40 patients with depression, and 40 healthy controls were matched. They completed questionnaires regarding alexithymia (TAS26) and depressive feelings (BDI-II). In addition, pain patients rated their subjective pain intensity (NRS). Quantitative sensory testings were conducted in all participants examining temperature (CPT, HPT) and mechanical (MPT, PPT) thresholds.

RESULTS

Analysis of variance showed that alexithymia was significantly increased in both patient groups compared to healthy controls, but with the highest amount in somatoform pain. Regression analyses confirmed that this finding was in part due to a high comorbidity of depressive feelings in both patient groups. We found a discrepancy between increased clinical pain ratings and elevated pressure pain thresholds, indicating a less intense mechanical pain perception in somatoform pain. Correlation analyses demonstrated a significant connection of subjective pain ratings and pressure pain thresholds with depressive feelings.

CONCLUSION

Contrary to the results of other experimental pain studies on chronic muskuloskeletal pain syndromes, we could not confirm central sensitization in somatoform pain disorder. Our findings place the somatoform pain disorder more in the direction of affective disorder such as depression. These findings may improve a better understanding of the disease and also have direct therapeutic implications. The high occurrence of alexithymia and depressive feelings in somatoform pain should be considered in diagnostic and therapeutic regimens of these patients.

[Undetected coccyx fracture in a woman with fibromyalgia]

This article presents the case of a 46-year-old woman with fibromyalgia with an undetected fracture of the coccyx. The heterogeneity of the symptoms of patients suffering from fibromyalgia including chronic widespread pain, vegetative and functional disorders, mental and physical exhaustion as well as sleep disorders can cause accidentally undetected comorbidities, especially if these are rare and predominantly present with pain as the main symptom. In the present case the reason for symptoms was detected only after 14 months of ineffective therapies and diagnostic procedures. The coccygeal pain was eliminated through a coccygectomy as ultima ratio. It should be nevertheless emphasized that patients with fibromyalgia suffer from a central pain-processing disorder. Indications for operative treatment must be very carefully considered. Surgery should only be considered in consultation with the patient and after failed conservative therapy.

Blood pressure-related pain modulation in fibromyalgia: Differentiating between static versus dynamic pain indicators

INTRODUCTION

Resting blood pressure (BP) has been found to be inversely associated with evoked pain responsiveness in healthy populations. However, some reports suggest that BP-related pain modulation may be dysfunctional in chronic pain patients. This study examined whether BP-related pain modulation, indexed by both static and dynamic evoked pain responses, is altered in fibromyalgia (FM) patients compared to pain-free individuals.

METHOD

Pain threshold and tolerance as static evoked pain measures and slowly repeated evoked pain (SREP) as a dynamic evoked pain index were measured in 30 FM patients and 27 healthy controls. BP was continuously recorded throughout a 5 minute pre-pain rest period.

RESULTS

SREP sensitization was observed only in the FM group. Higher BP predicted elevated pain threshold and tolerance in healthy individuals, but not in FM. Conversely, BP was inversely associated with SREP sensitization in FM whereas no association was found in healthy controls.

CONCLUSIONS

Static evoked pain measures suggested BP-related pain inhibitory dysfunction in FM. In contrast, for pain sensitization as indexed by SREP, FM displayed the expected BP-related inhibitory effects. BP-related pain modulation is manifested in FM differentially for static versus dynamic pain indicators. Use of both types of evoked pain measures may be valuable in the study of mechanisms underlying altered pain modulatory systems in FM.

The effectiveness of greater occipital nerve blockade in treating acute migraine-related headaches in emergency departments

OBJECTIVE

This study aimed to evaluate the effectiveness of a greater occipital nerve (GON) blockade against a placebo and classical treatments (non-steroidal anti-inflammatory drugs + metoclopramide) among patients who were admitted to the emergency department (ED) with acute migraine headaches.

METHOD

This prospective-randomized controlled study was conducted on patients with acute migraine headaches. The patients were randomly assigned to 3 treatment groups: the GON blockade group (nerve blockade with bupivacaine), the placebo group (injection of normal saline into the GON area), and the intravenous (IV) treatment group (IV dexketoprofen and metoclopramide). Sixty acute migraine attack patients were assigned to 3 groups of 20 patients each. The pain severity was assessed at 5, 15, 30, and 45 minutes with a 10-point pain scale score (PSS).

RESULTS

The mean decreases in the 5-, 15-, 30-, and 45-minutes PSS scores were greater in the GON blockade group than in the dexketoprofen and placebo groups. When comparing the 30- and 45-minutes PSS changes, a statistically significant difference was found among the 3 groups (P = .03 and P = .03, respectively).

CONCLUSION

A GON blockade was as effective as an IV dexketoprofen + metoclopramide treatment and superior to a placebo in patients with acute migraine headaches. Despite being an invasive procedure, a GON blockade might be an effective option for acute migraine treatment in the ED due to its rapid, easy, and safe application.

Abdominal skeletal muscle activity precedes spontaneous menstrual cramping pain in primary dysmenorrhea

BACKGROUND

Dysmenorrhea is a pervasive pain condition that affects 20-50% of reproductive-aged women. Distension of a visceral organ, such as the uterus, could elicit a visceromotor reflex, resulting in involuntary skeletal muscle activity and referred pain. Although referred abdominal pain mechanisms can contribute to visceral pain, the role of abdominal muscle activity has not yet been investigated within the context of menstrual pain.

OBJECTIVE

The goal of this study was to determine whether involuntary abdominal muscle activity precedes spontaneous episodes of menstrual cramping pain in dysmenorrheic women and whether naproxen administration affects abdominal muscle activity.

STUDY DESIGN

Abdominal electromyography activity was recorded from women with severe dysmenorrhea (n = 38) and healthy controls (n = 10) during menses. Simultaneously, pain was measured in real time using a squeeze bulb or visual analog rheostat. Ninety minutes after naproxen administration, abdominal electromyography activity and menstrual pain were reassessed. As an additional control, women were also recorded off menses, and data were analyzed in relation to random bulb squeezes. Because it is unknown whether mechanisms of menstrual cramps are different in primary or secondary dysmenorrhea/chronic pelvic pain, the relationship between medical history and abdominal muscle activity was examined. To further examine differences in nociceptive mechanisms, pressure pain thresholds were also measured to evaluate changes in widespread pain sensitivity.

RESULTS

Abdominal muscle activity related to random-bulb squeezing was rarely observed in healthy controls on menses (0.9 ± 0.6 episodes/hour) and in dysmenorrhea participants off menses (2.3 ± 0.6 episodes/hour). In dysmenorrheic participants during menses, abdominal muscle activity frequently preceded bulb squeezing indicative of menstrual cramping pain (10.8 ± 3.0 episodes/hour; P < .004). Whereas 45% of the women with dysmenorrhea (17 of 38) had episodes of abdominal muscle activity associated pain, only 13% (5 of 38) had episodes after naproxen (P = .011). Women with the abdominal muscle activity-associated pain were less likely to have a diagnosis for secondary dysmenorrhea or chronic pelvic pain (2 of 17) than women without this pain phenotype (10 of 21; P = .034). Similarly, women with the abdominal muscle activity-associated pain phenotype had less nonmenstrual pain days per month (0.6 ± 0.5) than women without the phenotype (12.4 ± 0.3; P = .002). Women with abdominal muscle activity-associated pain had pressure pain thresholds (22.4 ± 3.0 N) comparable with healthy controls (22.2 ± 3.0 N; P = .967). In contrast, women without abdominal muscle activity-associated pain had lower pressure pain thresholds (16.1 ± 1.9 N; P = .039).

CONCLUSION

Abdominal muscle activity may contribute to cramping pain in primary dysmenorrhea but is resolvable with naproxen. Dysmenorrheic patients without cramp-associated abdominal muscle activity exhibit widespread pain sensitivity (lower pressure pain thresholds) and are more likely to also have a chronic pain diagnosis, suggesting their cramps are linked to changes in central pain processes. This preliminary study suggests new tools to phenotype menstrual pain and supports the hypothesis that multiple distinct mechanisms may contribute to dysmenorrhea.

Cluster subgroups based on overall pressure pain sensitivity and psychosocial factors in chronic musculoskeletal pain: Differences in clinical outcomes

Objective: We aimed to empirically derive psychosocial and pain sensitivity subgroups using cluster analysis within a sample of individuals with chronic musculoskeletal pain (CMP) and to investigate derived subgroups for differences in pain and disability outcomes. Methods: Eighty female participants with CMP answered psychosocial and disability scales and were assessed for pressure pain sensitivity. A cluster analysis was used to derive subgroups, and analysis of variance (ANOVA) was used to investigate differences between subgroups. Results: Psychosocial factors (kinesiophobia, pain catastrophizing, anxiety, and depression) and overall pressure pain threshold (PPT) were entered into the cluster analysis. Three subgroups were empirically derived: cluster 1 (high pain sensitivity and high psychosocial distress; n = 12) characterized by low overall PPT and high psychosocial scores; cluster 2 (high pain sensitivity and intermediate psychosocial distress; n = 39) characterized by low overall PPT and intermediate psychosocial scores; and cluster 3 (low pain sensitivity and low psychosocial distress; n = 29) characterized by high overall PPT and low psychosocial scores compared to the other subgroups. Cluster 1 showed higher values for mean pain intensity (F_(2,77) = 10.58, p < 0.001) compared with cluster 3, and cluster 1 showed higher values for disability (F_(2,77) = 3.81, p = 0.03) compared with both clusters 2 and 3. Conclusions: Only cluster 1 was distinct from cluster 3 according to both pain and disability outcomes. Pain catastrophizing, depression, and anxiety were the psychosocial variables that best differentiated the subgroups. Overall, these results call attention to the importance of considering pain sensitivity and psychosocial variables to obtain a more comprehensive characterization of CMP patients' subtypes.

Effect of physical exercise on musculoskeletal pain in multiple body regions among healthcare workers: Secondary analysis of a cluster randomized controlled trial

BACKGROUND

While physical exercise is beneficial for back and neck-shoulder pain, only few intervention studies have evaluated effects on pain in multiple body regions. Furthermore, direct measurement of pain threshold can provide additional information to self-reported pain intensity.

OBJECTIVES

To evaluate the effect of workplace versus home-based physical exercise on pressure pain threshold (PPT) and musculoskeletal pain intensity in multiple body regions.

STUDY DESIGN

Secondary analysis of an examiner-blinded, cluster randomized controlled trial with allocation concealment.

METHOD

Two-hundred female healthcare workers from 18 departments at three hospitals were cluster-randomized to 10 weeks of: 1) home-based physical exercise (HOME) performed alone during leisure time for 5 × 10 min per week or 2) workplace physical exercise (WORK) performed in groups during working hours for 5 × 10 min per week and up to 5 motivational coaching sessions. PPT (neck, lower back, lower leg) and perceived pain intensity in multiple body regions (feet, knee, hips, lower and upper back, elbow, hand, shoulder, neck, and head) were measured at baseline and 10-week follow-up.

RESULTS

In some of the body regions, PPT and pain intensity improved more following WORK than HOME. Between-group differences at follow-up (WORK vs. HOME) were 41 kPA [95% CI 13-70, effect size (ES): 0.22] for PPT in the lower back, and -0.7 [95% CI -1.0-0.3, ES: 0.26] and -0.6 points [95% CI -0.9--0.2, ES: 0.23] for pain intensity in the lower back and feet, respectively. HOME did not improve more than WORK for any of the measurements.

CONCLUSION

Physical exercise recommendations for healthcare workers should consider the setting, i.e. performing supervised group-based exercise at work and motivational coaching sessions is more effective than exercising alone at home.

Are the ACR 2010 diagnostic criteria for fibromyalgia better than the 1990 criteria?

Fibromyalgia (FM) is difficult to diagnose and manage chronic pain condition whose symptoms have no clear pathophysiological cause, although it is thought that patient hypersensitivity to a range of stimuli may give rise to mechanical hyperalgesia as a result of altered central nociceptive processing. The 1990 American College of Rheumatology (ACR) classification criteria, which have been widely used in clinical practice, require the existence of chronic widespread pain (CWP) for >3months, and the presence of at least 11 out of 18 specified tender points upon digital palpation, although this latter criterion has long been criticised. The newer 2010 ACR diagnostic criteria state that FM can be defined as CWP associated with somatic symptoms, and recommend the use of a widespread pain index and a scale to rate symptom severity. A modified version of the 2010 criteria removed the physician assessment of the extent of somatic symptoms and replaced it by a summary score of three self-reported symptoms, thus making it easier to use while maintaining its sensitivity. This review discusses the advantages and limitations of all of these criteria.

Hip Pain and Mobility Deficits-Hip Osteoarthritis: Revision 2017

The Orthopaedic Section of the American Physical Therapy Association (APTA) has an ongoing effort to create evidence-based practice guidelines for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). The purpose of these revised clinical practice guidelines is to review recent peer-reviewed literature and make recommendations related to hip pain and mobility deficits. J Orthop Sports Phys Ther. 2017;47(6):A1-A37. doi:10.2519/jospt.2017.0301.

[Characteristic of the normal values of the pain threshold values in the dorsal region of the young women obtained by the pressure algometry method under different condition]

The application of modern techniques for different types of massage and manual therapy is associated with the exposure of the paravetrebral points. The knowledge of pain threshold values at these points is of great practical significance.

AIM

The objective of the present study was to obtain the statistical characteristics of the individual pressure pain threshold (PPT) for the healthy women and patients presenting with minor disturbances of spinal motion segments (SMS) at the trigger points on the back. The secondary objective was to estimate the dependence of the PPT parameters on a variety of conditions.

MATERIAL AND METHODS

Two groups of female volunteers (students of the South Ural State Humanitarian Pedagogical University aged 19-21 years) were formed, one composed of the girls in the quiescent state (group 1, n=45), the other comprised of the girls in the state of emotional agitation and prepared for physical activity (group 2, n=105). Each group was split into two sub-groups depending on the presence or absence of complaints about the state of the SMS. PPT was evaluated in terms of kg/cm2 with the use of the Wagner FPX algometer (USA) at 3 paired paravertebral points localized at different levels: the second and third lumbar vertebrae (LII-LIII); the ninth-to-tenth thoracic vertebrae (DIХ-DХ), the seventh cervical, and first thoracic vertebrae (CVII-DI); as well as in pairs on the trapezius muscles in their upper parts. The height, weight, and body mass index of the participants in the study were measured.

RESULTS

The PPTs values at the selected points on the back were log-normally distributed. The minimum values were measured on the trapezoidal muscles (about 2 kg/cm2) and the maximum ones in the lumbar spineregion (up to 7 kg/cm2). Complaints about the condition of SMS in group 1 were associated with the decrease of the PPT values at the paravertebral points on the neck and the lower back. No decrease of the PPT values in connection with the complaints was documented in the patients of group 2. The PPT values determined in the women of group 2 were statistically higher than in those of group 1 at all points studied and in all the subgroups; the differences ranged from 20% to 40%. The PPTs values at different points of the back correlated significantly between each other (Spearman correlation coefficient 0.6-0.9, p<0.001). In all the groups statistically significant asymmetry of the PPT values was documented (Kruskal-Wallis test, p<0.05); the right-side PPT values were lower than the left-side ones, with the difference amounting to 2-8%.

CONCLUSION

The conditions of PPT measurements at the paravertebral points have a significant impact on the resultant values, being higher when the subject is ready for performing the physical exercises. The complaints about the state of the SMS are associated with the decrease in the PPT values that are lower on the right side of the body than on its left side.

Gender Differences in Symptoms, Health-Related Quality of Life, Sleep Quality, Mental Health, Cognitive Performance, Pain-Cognition, and Positive Health in Spanish Fibromyalgia Individuals: The Al-Ándalus Project

Objective. To test the gender differences in tenderness, impact of fibromyalgia, health-related quality of life, fatigue, sleep quality, mental health, cognitive performance, pain-cognition, and positive health in Spanish fibromyalgia patients and in age-matched nonfibromyalgia individuals from the same region. To test the optimal cut-off score of the different tender points for women and men. Methods. A total of 405 (384 women) fibromyalgia versus 247 (195 women) nonfibromyalgia control participants from southern Spain (Andalusia) took part in this cross-sectional study. The outcomes studied were assessed by means of several tests. Results. In the fibromyalgia group, men showed better working memory than women (all, P < 0.01), whereas sleep latency was lower in women compared to men (P = 0.013). In the nonfibromyalgia group, men showed higher pain threshold in all the tender points (all, P < 0.01), except in right and left lateral epicondyle. Furthermore, men showed better working memory than women (all, P < 0.01), whereas memory performance was better in women compared to men (all, P ≤ 0.01). Conclusion. The results of the present study do not support consistent evidence of gender differences in fibromyalgia-related symptoms. However, it seems that detriment of some symptoms (especially pain) in fibromyalgia men compared with their nonfibromyalgia counterparts is greater than those of fibromyalgia women compared with their nonfibromyalgia peers.

Pain Threshold Tests in Patients With Heel Pain Syndrome

BACKGROUND

Pressure pain threshold (PPT) is a useful tool for evaluating mechanical sensitivity in patients suffering from various musculoskeletal disorders. However, no previous study has investigated PPT in the heel of patients experiencing plantar heel pain syndrome (PHPS). The aim of this study was to compare PPT levels and topographic presentation of sensitivity in the heel of patients with PHPS and in healthy controls.

METHODS

The reliability of PPT testing in patients with PHPS was assessed for intra- and interrater recordings. The PPT levels of 40 feet in each group were then assessed on 5 predetermined sites in the heel using a standardized measurement protocol. Patient functional status (FS) as measured by the Foot & Ankle Computerized Adaptive Test was employed as an external reference.

RESULTS

Multivariate analysis of covariance revealed no group differences for PPTs at all sites (P = .406). Age (P = .099) or BMI (P = .510) did not affect PPT values, although there was an effect on gender (P = .006). The analysis revealed significant differences between sites (P < .001) demonstrating a diverse topographic distribution. In the PHPS group, PPT levels at the anterior/medial, posterior/medial and central sites were significantly lower than at the posterior/lateral and anterior/lateral sites (P < .05). For the control group, PPT levels at the anterior/medial site were significantly lower than all other sites (P < .001).

CONCLUSION

No significant differences were found between PPT of the PHPS patients and controls, therefore, PPT cannot be recommended as an assessment tool for these patients. The topographic distribution indicated low PPT levels at the anterior/medial area of the heel in patients with PHPS and controls.

LEVEL OF EVIDENCE

Level II, comparative study.

Effect of somatosensory amplification and trait anxiety on experimentally induced orthodontic pain

The perception of pain varies considerably across individuals and is affected by psychological traits. This study aimed to investigate the combined effects of somatosensory amplification and trait anxiety on orthodontic pain. Five-hundred and five adults completed the State Trait Anxiety Inventory (STAI) and the Somatosensory Amplification Scale (SSAS). Individuals with combined STAI and SSAS scores below the 20th percentile (LASA group: five men and 12 women; mean age ± SD = 22.4 ± 1.3 yr) or above the 80th percentile (HASA group: 13 men and seven women; mean age ± SD = 23.7 ± 1.0 yr) were selected and filled in the Oral Behaviors Checklist (OBC). Orthodontic separators were placed for 5 d in order to induce experimental pain. Visual analog scales (VAS) were administered to collect ratings for occlusal discomfort, pain, and perceived stress. Pressure pain thresholds (PPT) were measured. A mixed regression model was used to evaluate pain and discomfort ratings over the 5-d duration of the study. At baseline, the LASA group had statistically significantly higher PPT values for the masseter muscle than did the HASA group. During the experimental procedure, the HASA group had statistically significantly higher discomfort and pain. A significant difference in pain ratings during the 5 d of the study was found for subjects in the HASA group. Higher OBC values were statistically significantly positively associated with pain. Somatosensory amplification and trait anxiety substantially affect experimentally induced orthodontic pain.

Measuring mechanical pain: the refinement and standardization of pressure pain threshold measurements

Pain thresholds are widely used in behavioral research, but unlike other pain modalities, a standardized assessment of pressure pain remains a challenge. In this research, we describe the application of an automatic pressure algometer with a linear increase in force. Ergonomically designed fixation devices were developed to increase the accuracy and to shorten the time of each measurement. Ten healthy volunteers were included in a pilot study to test the algometry method. Pressure pain thresholds (PPTs) were investigated over 2 experimental days in three nonconsecutive runs at 29 measurement sites. During the experiment, subjects reported their subjective sleepiness, level of state-anxiety, psychological status and the perceived pain intensity of each measurement. Pain intensity ratings indicate that instructions were followed. State-anxiety and subjective sleepiness levels were low throughout the experiment. The method has proven to be suitable for standardized PPT measurements across the body in an ergonomic, safe, and user-friendly fashion.

Association of cardiorespiratory fitness with pressure pain sensitivity and clinical pain in women with fibromyalgia

The aim of the present study was to assess the association of cardiorespiratory fitness (CRF) with pressure pain sensitivity and clinical pain in women with fibromyalgia (FM). Thirty-one women with FM were included in the study. Pressure pain sensitivity was assessed with an electronic pressure dolorimeter. The average pressure pain threshold (PPT) from the 18 FM-related tender points and the tender points count (TPC) were recorded. Clinical pain was assessed on a 10-cm visual analog scale (VAS; from the FM impact questionnaire). The patients performed an incremental treadmill test, which consisted in six increasing workloads. Gas exchange was continuously monitored, and peak oxygen uptake (as measure of CRF) was recorded. Pairwise correlation and multiple linear regression were used to examine the association of CRF with PPT and VAS, and binary logistic regression assessed the odds of having <18 positive tender points as a function of CRF. The correlations of CRF with the average PPT and VAS were 0.355, (P < 0.001) and 0.058 (P > 0.05), respectively. Regression analyses revealed that CRF was associated with the PPT (B = 0.093; 95 % CI 0.064-0.122; P < 0.001; R (2) = 0.306) and TPC (OR 1.51; 95 % CI 1.30-1.75; P < 0.001) but not with VAS (B = 0.068; 95 % CI -0.061-0.197; P > 0.05). The findings of this study suggest that CRF is associated with pressure pain sensitivity but not with clinical pain in women with FM. Further longitudinal and intervention studies are needed to determine whether CRF could be involved in some mechanisms of pain processing.

Effects of Temperature on Chronic Trapezius Myofascial Pain Syndrome during Dry Needling Therapy

The purpose of this study was to investigate the effects of temperature on chronic trapezius myofascial pain syndrome during dry needling therapy. Sixty patients were randomized into two groups of dry needling (DN) alone (group A) and DN combined with heat therapy group (group B). Each patient was treated once and the therapeutic effect was assessed by the visual analogue scale (VAS), pressure pain threshold (PPT), and the 36-item short form health survey (SF-36) at seven days, one month, and three months after treatment. Evaluation based on VAS and PPT showed that the pain of patients in groups A and B was significantly (P < 0.05) relieved at seven days, one month, and three months after treatment Compared to before treatment. There was significantly (P < 0.05) less pain in group B than group A at one and three months after treatment. The SF-36 evaluation demonstrated that the physical condition of patients in both groups showed significant (P < 0.05) improvement at one month and three months after treatment than before treatment. Our study suggests that both DN and DN heating therapy were effective in the treatment of trapezius MPS, and that DN heating therapy had better long-term effects than DN therapy.

An insight into the gastrointestinal component of fibromyalgia: clinical manifestations and potential underlying mechanisms

Fibromyalgia syndrome is characterized by chronic generalized pain accompanied by a broad symptomatologic spectrum. Besides chronic fatigue, sleep disturbances, headaches and cognitive dysfunction that are extensively described in the literature, a considerable proportion of patients with fibromyalgia experience gastrointestinal symptoms that are commonly overlooked in the studies that are not specifically dedicated to evaluate these manifestations. Nevertheless, various attempts were undertaken to explore the gastrointestinal dimension of fibromyalgia. Several studies have demonstrated an elevated comorbidity of irritable bowel syndrome (IBS) among patients with fibromyalgia. Other studies have investigated the frequency of presentation of gastrointestinal symptoms in fibromyalgia in a nonspecific approach describing several gastrointestinal complaints frequently reported by these patients such as abdominal pain, dyspepsia and bowel changes, among others. Several underlying mechanisms that require further investigation could serve as potential explanatory hypotheses for the appearance of such manifestations. These include sensitivity to dietary constituents such as gluten, lactose or FODMAPs or alterations in the brain-gut axis as a result of small intestinal bacterial overgrowth or subclinical enteric infections such as giardiasis. The gastrointestinal component of fibromyalgia constitutes a relevant element of the multidisciplinary pathophysiologic mechanisms underlying fibromyalgia that need to be unveiled, as this would contribute to the adequate designation of relevant treatment alternatives corresponding to these manifestations.

Do comorbid fibromyalgia diagnoses change after a functional restoration program in patients with chronic disabling occupational musculoskeletal disorders?

STUDY DESIGN

A retrospective study of prospectively collected data.

OBJECTIVE

To determine whether comorbid fibromyalgia, identified in patients with chronic disabling occupational musculoskeletal disorders (CDOMDs), resolves with a functional restoration program (FRP).

SUMMARY OF BACKGROUND DATA

Fibromyalgia involves widespread bodily pain and tenderness to palpation. In recent studies, 23% to 41% of patients with CDOMDs entering an FRP had comorbid fibromyalgia, compared with population averages of 2% to 5%. Few studies have examined whether fibromyalgia diagnoses resolve with any treatment, and none have investigated diagnosis responsiveness to an FRP.

METHODS

A consecutive cohort of patients with CDOMDs (82% with spinal disorders and all reporting chronic spinal pain) and comorbid fibromyalgia (N = 117) completed an FRP, which included quantitatively directed exercise progression and multimodal disability management. Diagnosis responsiveness, evaluated at discharge, created 2 groups: those who retained fibromyalgia and those who did not. These groups were compared with chronic regional lumbar pain only patients (LO group, n = 87), lacking widespread pain and fibromyalgia.

RESULTS

Of the patients with comorbid fibromyalgia, 59% (n = 69) retained the fibromyalgia diagnosis (RFM group) and 41% (n = 48) lost the fibromyalgia diagnosis (LFM group) at discharge. Although all 3 groups reported decreased pain intensity, disability, and depressive symptoms from admission to discharge, RFM patients reported higher symptom levels than the LFM and LO groups at discharge. The LFM and LO groups were statistically similar. At 1-year follow-up, LO patients demonstrated higher work retention than both fibromyalgia groups (P < 0.03).

CONCLUSION

Despite a significant comorbid fibromyalgia prevalence in a cohort of patients with CDOMDs entering an FRP, 41% of patients with an initial fibromyalgia diagnosis no longer met diagnostic criteria for fibromyalgia at discharge and were indistinguishable from LO patients on pain, disability, and depression symptoms. However, both fibromyalgia groups (LFM and RFM) had lower work retention than LO patients 1 year later, suggesting that an FRP may suppress symptoms of fibromyalgia in a subset of patients, but prolonged fibromyalgia-related disability may be more difficult to overcome.

LEVEL OF EVIDENCE

2.

Association between Neck/Shoulder Pain and Trapezius Muscle Tenderness in Office Workers

Background. Neck/shoulder pain is a common musculoskeletal disorder among adults. The pain is often assumed to be related to muscular tenderness rather than serious chronic disease. Aim. To determine the association between neck/shoulder pain intensity and trapezius muscle tenderness in office workers. Methods. 653 employees from two large office workplaces in Copenhagen, Denmark, replied to a questionnaire on health and working conditions (mean: age 43 years, body mass index 24 kg·m⁻², computer use 90% of work time, 73% women). Respondents rated intensity of neck/shoulder pain during the previous three months on a scale of 0–10 and palpable tenderness of the upper trapezius muscle on a scale of “no tenderness,” “some tenderness,” or “severe tenderness.” Odds ratios for tenderness as a function of neck/shoulder pain intensity were determined using cumulative logistic regression controlled for age, gender, and chronic disease. Results. The prevalence of “no,” “some,” and “severe” tenderness of the trapezius muscle was 18%, 59%, and 23% in women and 51%, 42%, and 7% in men, respectively (chi-square, P < 0.0001). Participants with “no,” “some,” and “severe” tenderness of the trapezius muscle, respectively, rated their neck/shoulder pain intensity to 1.5 (SD 1.6), 3.8 (SD 2.0), and 5.7 (SD 1.9) for women and 1.4 (SD 1.4), 3.1 (SD 2.2), and 5.1 (SD 1.7) for men. For every unit increase in neck/shoulder pain intensity, the OR for one unit increase in trapezius tenderness was 1.86 (95% confidence interval 1.70 to 2.04). Conclusion. In office workers, a strong association between perceived neck/shoulder pain intensity and trapezius muscle tenderness exists. The present study provides reference values of pain intensity among office workers with no, some, and severe tenderness of the trapezius muscle.