Digital pain extent is associated with pain intensity but not with pain-related cognitions and disability in people with chronic musculoskeletal pain: a cross-sectional study.

BACKGROUND: To evaluate whether digital pain extent is associated with an array of psychological factors such as optimism, pessimism, expectations of recovery, pain acceptance, and pain self-efficacy beliefs as well as to analyse the association between digital pain extent and pain intensity and pain-related disability in people with chronic musculoskeletal pain. METHODS: A descriptive cross-sectional study conducted in a primary health care setting was carried out including 186 individuals with chronic musculoskeletal pain. Patient-reported outcomes were used to assess psychological factors, pain intensity, and pain-related disability. Digital pain extent was obtained from pain drawings shaded using a tablet and analysed using novel customized software. Multiple linear regression models were conducted to evaluate the association between digital pain extent and the aforementioned variables. RESULTS: Digital pain extent was statistically significantly associated with pain intensity. However, digital pain extent was not associated with any psychological measure nor with pain-related disability. DISCUSSION: The results did not support an association between digital pain extent and psychological measures.

Increased resistance towards fatigability in patients with facioscapulohumeral muscular dystrophy.

PURPOSE: In facioscapulohumeral muscular dystrophy (FSHD) fatigue is a major complaint. We aimed to investigate whether during isometric sustained elbow flexions, performance fatigability indexes differ in patients with FSHD with respect to healthy controls. METHODS: Seventeen patients with FSHD and seventeen healthy controls performed two isometric flexions of the dominant biceps brachii at 20% of their maximal voluntary contraction (MVC) for 2 min and then at 60% MVC until exhaustion. Muscle weakness was characterized as a percentage of predicted values. Maximal voluntary strength, endurance time and performance fatigability indices (mean frequency of the power spectrum (MNF), muscle fiber conduction velocity (CV) and fractal dimension (FD)), extracted from the surface electromyogram signal (sEMG) were compared between the two groups. RESULTS: In patients with FSHD, maximal voluntary strength was 68.7% of predicted value (p < 0.01). Compared to healthy controls, FSHD patients showed reduced MVC (p < 0.001; r = 0.62) and lower levels of performance fatigability, characterized by reduced rate of changes in MNF (p < 0.01; r = 0.56), CV (p < 0.05; 0.37) and FD (p < 0.001; r = 0.51) and increased endurance time (p < 0.001; r = 0.63), during the isometric contraction at 60% MVC. CONCLUSION: A decreased reduction in the slopes of all the considered sEMG parameters during sustained isometric elbow flexions suggests that patients with FSHD experience lower levels of performance fatigability compared to healthy controls.

Assessment of neuropathic pain after spinal cord injury using quantitative pain drawings.

STUDY DESIGN: Clinimetric cross-sectional cohort study in adults with paraplegic spinal cord injury (SCI) and neuropathic pain (NP). OBJECTIVE: To assess the reliability of standardized quantitative pain drawings in patients with NP following SCI. SETTING: Hospital-based research facility at the Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland. METHODS: Twenty individuals with chronic thoracic spinal cord injury and neuropathic pain were recruited from a national and local SCI registry. A thorough clinical examination and pain assessments were performed. Pain drawings were acquired at subsequent timepoints, 13 days (IQR 7.8-14.8) apart, in order to assess test-retest reliability. RESULTS: The average extent [%] and intensity [NRS 0-10] of spontaneous NP were 11.3% (IQR 4.9-35.8) and 5 (IQR 3-7), respectively. Pain extent showed excellent inter-session reliability (intraclass correlation coefficient 0.96). Sensory loss quantified by light touch and pinprick sensation was associated with larger pain extent (rpinprick = -0.47, p = 0.04; rlight touch = -0.64, p < 0.01). CONCLUSION: Assessing pain extent using quantitative pain drawings is readily feasible and reliable in human SCI. Relating information of sensory deficits to the presence of pain may provide distinct insights into the interaction of sensory deafferentation and the development of neuropathic pain after SCI.

Patterns of pain location in music students: a cluster analysis.

BACKGROUND: According to existing literature, musicians experience high rates of musculoskeletal (MSK) disorders involving different anatomical areas. The aim of the study was to identify patterns of pain location in a sample of music students enrolled in different pan-European music institutions. A further goal was to explore the association between the identified pain patterns and students' characteristics. METHODS: A total of 340 music students (mean age 23.3 years, 66.2% female) with current MSK pain completed a web-based questionnaire including both background information (i.e. lifestyle and physical activity, practice habits) and clinical features (i.e. pain characteristics, disability, pain self-efficacy, psychological distress, perfectionism and fatigue). RESULTS: Five patterns of pain location were identified by hierarchical cluster analysis: wrist pain (WP) representing 22.6% of the total sample, widespread pain (WSP) (16.9%), right shoulder pain (RSP) (18.5%), both shoulders pain - left concentrated (LSP) (23.2%), neck and back pain (NBP) (18.8%). Amongst the identified patterns of pain location, bivariate analysis identified the WSP cluster as containing the largest number of associated variables. Participants in this cluster reported a higher percentage of women (p < .05), a higher perceived exertion (p < .01) and psychological distress (p < .001), as well as a lower level of self-efficacy (p < .01). Similarly, a higher percentage of participants included in the WSP cluster perceived their musical activity as the main cause of their MSK pain (p < .01). Additionally, a higher level of disability in relation to playing-related activity was reported by participants included in the WP and WSP clusters (p < .001). The RSP cluster was characterised by a higher percentage of participants playing an instrument in a neutral position (p < .001) and lower levels of socially prescribed perfectionism (p < .01). A higher percentage of participants playing an instrument with both arms elevated in the left quadrant position were included in the LSP cluster and a higher percentage of singers were included in the NBP cluster (p < .001). CONCLUSIONS: Five distinct patterns of pain location were identified and their associations with the students' characteristics were explored. These findings may be helpful in the exploration of different aetiologies of MSK pain among musicians and in the development of targeted preventive strategies and treatments.

Dorsal Root Ganglion Stimulation for the Management of Intractable Painful Polyneuropathy: A Prospective Pilot Study.

OBJECTIVES: Dorsal root ganglion stimulation (DRGS) is a promising neurostimulation modality in the treatment of painful polyneuropathy. The aim of this prospective pilot study was to investigate the effect of DRGS on pain intensity in patients with intractable painful polyneuropathy. MATERIALS AND METHODS: Nine patients with chronic, intractable painful polyneuropathy in the lower limbs were recruited. In each subject, between two and four DRGS leads were placed at the level of the L5 and S1 dorsal root ganglion. If trial stimulation was successful, a definitive implantable pulse generator (IPG) was implanted. Pain intensity was scored using an 11-point numeric rating scale (NRS) and reported as median and interquartile range (IQR), and compared to baseline values using the Wilcoxon signed-rank test. Additionally, patients' global impression of change (PGIC), pain extent, presence of neuropathic pain, physical functioning, quality of life, and mood were assessed. RESULTS: Eight out of nine patients had a successful trial phase, of which seven received an IPG. Daytime pain decreased from a median (IQR) NRS score of 7.0 (5.9-8.3) to 2.0 (1.0-3.5) and 3.0 (1.6-4.9) in the first week and at six months after implantation, respectively. Similar effects were observed for night time and peak pain scores. CONCLUSIONS: The results of this study suggest that DRGS significantly reduces both pain intensity and PGIC in patients with intractable painful polyneuropathy in the lower extremities. Large-scale clinical trials are needed to prove the efficacy of DRGS in intractable painful polyneuropathy.

Digital pain drawings are a useful and reliable tool for assessing patients with temporomandibular disorders.

BACKGROUND: Temporomandibular disorders (TMD) are characterised by complex symptomatology and their assessment can be enhanced using pain drawings (PD). OBJECTIVES: To evaluate the location and extent of pain in people TMD using digital PD, and to explore their association with clinical features. Reliability of pain extent and pain location using PD was also assessed. METHODS: Forty volunteers with TMD completed two consecutive digital PDs. Clinical features were captured from self-reported questionnaire. Additionally, secondary hyperalgesia was measured using the pressure pain threshold (PPT). The correlation between pain extent and clinical features was investigated using Spearman rank correlation coefficients. Reliability of pain extent was evaluated using intraclass correlation coefficient (ICC) and Bland-Altman plots. The Jaccard index was computed to assess the reliability of pain location. RESULTS: Analysis of the PDs indicated that people with TMD commonly experience pain in other body regions including the neck, the shoulder and the low back. Except for PPT and pain catastrophising, all other clinical features were significantly correlated with pain extent. The ICCs of pain extent for all body charts were very high (ICCs 95% CI from 0.73 to 0.96), and Bland-Altman plots showed mean biases close to zero with narrow limits of agreement. The reliability of pain location was also supported by Jaccard index mean scores above 0.68. CONCLUSIONS: People with TMD showed widespread pain, and pain extent was associated with pain intensity, neck and headache-related disability, depression, anxiety, hyperventilation and central sensitivity. The reliability of measuring pain extent and pain location was confirmed.

Profiling the Extent and Location of Pain in Migraine and Cervicogenic Headache: A Cross-sectional Single-Site Observational Study.

OBJECTIVES: The primary aim was to quantify and compare the location and extent of pain in people with either episodic migraine, chronic migraine, or cervicogenic headache. A secondary aim was to examine the associations between pain extent and headache features, quality of life, and psychological distress for each headache type. DESIGN: A cross-sectional, single-site, observational study. SETTING: Headache outpatient clinic. SUBJECTS: From a sample of 390 patients, 114 patients with migraine or cervicogenic headache (48 episodic migraine, 30 chronic migraine, 36 cervicogenic headache) were eligible for the study. METHODS: Pain location and extent were determined using a novel approach for digital pain drawing acquisition and analysis. Headache features included intensity and history duration. Quality of life was measured using the SF-36 and psychological distress using the Hospital Anxiety and Depression Scale. RESULTS: Overall, pain was most frequently reported in the frontal and temporal regions in patients with either episodic or chronic migraine, whereas pain was most frequent in the suboccipital region in patients with cervicogenic headache. A larger pain extent was moderately correlated with higher headache intensity (rs = 0.53, P = 0.003) and poorer quality of life (rs ranged from -0.36 to -0.40, P < 0.05) in patients with chronic migraine, whereas pain extent was associated with longer headache duration in those with cervicogenic headache (rs = 0.35, P = 0.04). No correlation was found between pain extent and psychological features for any headache type (P > 0.05). CONCLUSIONS: Despite some differences, there was a large symptomatic overlap between headache types, highlighting the limitations of using pain location in the differential diagnosis of headache.

The Extent of Pain Is Associated With Signs of Central Sensitization in Patients With Hip Osteoarthritis.

BACKGROUND: Central sensitization may be present in some patients with hip osteoarthritis (OA), often reflected as widespread pain. We examine the association between pain extent with signs of central sensitization and other clinical and psychological features in patients with hip OA. METHODS: Thirty patients with hip OA were recruited for this cross-sectional observational study. Participants completed pain drawings on a digital tablet, which displayed frontal and dorsal views of the body. The pain extent (%) for each participant was determined by combining the frontal and dorsal pixels shaded and dividing by the total pixels of the body chart area. Participants completed patient-reported outcome measures to assess for signs and symptoms of central sensitization and psychosocial factors. Quantitative sensory testing including pain pressure thresholds (PPTs) and thermal pressure thresholds was performed at points anatomically local and distant from the hip. RESULTS: Women had significantly greater pain extent (6.71%) than men (2.65%) (z = -2.76, P < 0.01). Across all participants, increased pain extent was significantly associated with higher scores on the Widespread Pain Index (r2  = 0.426, P < 0.05), painDETECT questionnaire (r2  = 0.394, P < 0.05), and Pain Catastrophizing Scale (r2  = 0.413, P < 0.05), and with lower PPTs at the thenar eminence (r2  = -0.410, P < 0.05), vastus lateralis (r2  = -0.530, P < 0.01), vastus medialis (r2  = 0.363, P < 0.05), and greater trochanter (r2  = -0.373, P < 0.05). CONCLUSIONS: Greater pain extent was associated with several measures of signs and symptoms of central sensitization in patients with hip OA. These results support the utility of the pain drawing for identifying signs of central sensitization in patients with hip OA.

Perceived Pain Extent Is Not Associated with Physical, Psychological, or Psychophysical Outcomes in Women with Carpal Tunnel Syndrome.

OBJECTIVE: Our aims were 1) to investigate whether perceived pain extent, assessed from the pain drawing, relates to clinical, psychological, and psychophysical outcomes in women with carpal tunnel syndrome (CTS); 2) to assess differences in pain extent depending on the presence of median or extramedian symptoms; and 3) to investigate differences in pain extent according to severity (minimal, moderate, or severe) or laterality (unilateral or bilateral) of CTS. METHODS: One hundred forty (N = 140) women with CTS completed pain drawings, which were subsequently digitized, allowing pain extent to be calculated. Clinical features including pain intensity (numerical pain rating scale, 0-10) and disability (Boston Carpal Tunnel Questionnaire), psychological features including depression (Beck Depression Inventory), and psychophysical variables (pressure pain and thermal pain thresholds) were assessed. Spearman rho correlation coefficients were used to reveal the correlations between pain extent and other outcomes. Differences in pain extent according to severity (minimal, moderate, severe) or laterality (unilateral, bilateral) and the presence of extramedian symptoms were also evaluated. RESULTS: No significant associations were identified between pain extent and clinical, psychological, or psychophysical outcomes. Women with extramedian symptoms (88%) exhibited a larger (P < 0.001) pain extent (total: 24.2% ± 13.5%) than women with median symptoms (12%; total: 12.2% ± 6.9%). Pain extent was not significantly different depending on the severity or laterality of the symptoms. CONCLUSIONS: Pain extent in the upper extremity was not associated with clinical, psychological, or psychophysical variables and was not related to the severity or laterality of the symptoms in women with CTS.

A longitudinal investigation of the factors associated with increased RISk of playing-related musculoskeletal disorders in MUsic students (RISMUS): a study protocol.

BACKGROUND: The achievement and improvement of skills in musical techniques to reach the highest levels of performance may expose music students to a wide range of playing-related musculoskeletal disorders (PRMDs). In order to establish effective solutions for PRMDs and to develop future preventive measures, it is fundamental to firstly identify the main risk factors that play a significant role in the development of musculoskeletal conditions and symptoms. The aim of the study is to identify those factors associated with increased risk of PRMDs among music students. A further goal is to characterise this population and describe the clinical features of PRMDs, as well as to determine the evolving course of PRMDs in music students during their training. METHODS: One hundred and ninety schools have been invited to participate in this study, sixty of which have already confirmed officially their support for the investigation's recruitment procedures, by means of a subsequent distribution of the link to a web-based questionnaire to their student groups (total potential student numbers available: n = 12,000 [based on ~ 200 students per school on average, and 60 volunteering schools]; expected number of students: n = 3000 [based on a 25% response rate from the 12,000 students attending the 60 volunteering schools]). The web-based questionnaire includes questions about any PRMD that students have experienced during their training, and different potential risk factors (i.e. lifestyle and physical activity, practice habits, behaviour toward prevention and health history, level of stress, perfectionism, fatigue and disability). Overall recurrence or new onsets of PRMDs will be assessed at 6 and 12 months after the first data collection to investigate and record the development of new incidents within a period of a year and to enable characterisation of the nature and the evolving course of PRMDs. DISCUSSION: To the best of our knowledge, no other longitudinal studies on risk factors for PRMDs among music students have been conducted so far. Therefore, this study can be considered as an opportunity to begin filling the gaps within current research in this field and to generate new knowledge within musical contexts in education and employment. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT03622190 ), registration date 09/08/2018.

Proteins and Signaling Pathways Response to Dry Needling Combined with Static Stretching Treatment for Chronic Myofascial Pain in a RAT Model: An Explorative Proteomic Study.

A quantitative proteomic analysis of the response to dry needling combined with static stretching treatment was performed in a rat model of active myofascial trigger points (MTrPs). 36 rats were divided into a model group (MG), a stretching group (SG) and a dry needling combined with stretching group (SDG). We performed three biological replicates to compare large-scale differential protein expression between groups by tandem mass tag (TMT) labeling technology based on nanoscale liquid chromatography mass spectrometry analysis (LC⁻MS/MS). Hierarchical clustering, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment and protein-protein interaction network analyses were performed for the general characterization of overall enriched proteins. For validation of the results of TMT, the candidate proteins were verified by parallel reaction monitoring (PRM) analysis. 285 differentially expressed proteins between groups were identified and quantified. Tight junction pathway played a dominant role in dry needling combined with static stretching treatment for the rat model of active MTrPs. Three candidate proteins, namely actinin alpha 3, calsequestrin-1 and parvalbumin alpha, were further validated, consistent with the results of LC⁻MS/MS. This is the first proteomics-based study to report the therapeutic mechanism underlying dry needling and static stretching treatment for MTrPs. Further functional verification of the potential signaling pathways and the enriched proteins is warranted.

Influence of Clinical, Psychological, and Psychophysical Variables on Long-term Treatment Outcomes in Carpal Tunnel Syndrome: Evidence From a Randomized Clinical Trial.

OBJECTIVE: To assess the influence of clinical, psychological, and psychophysical variables on long-term clinical outcomes after the application of either physical therapy or surgery in women presenting with carpal tunnel syndrome (CTS). METHODS: A secondary analysis of a randomized trial investigating the efficacy of manual therapy including desensitization maneuvers of the central nervous system against surgery in 120 women with CTS was performed. Clinical outcomes including pain intensity, function, or symptom severity were assessed at 6 and 12 months post-intervention. Participants completed at baseline several clinical (pain intensity, function, and symptom severity), psychological (depression), and psychophysical (pressure pain thresholds and pain extent) variables, which were included as predictors. Multiple regression analyses were conducted to assess the relationship between baseline variables and clinical outcomes at 6 and 12 months post-intervention. RESULTS: The regression models indicated that higher scores of each clinical outcome (ie, intensity of pain or symptom severity) at baseline predicted better outcomes at 6 and 12 months post-intervention (from 15% to 65% of variance) in both groups. Lower pressure pain thresholds over the carpal tunnel at baseline predicted poorer clinical outcomes at 6 and 12 months post-intervention (from 5% to 20% of variance) in the physical therapy group, whereas higher depressive symptoms at baseline contributed to poorer outcomes at 6 and 12 months post-intervention (from 5% to 15% of the variance) within the surgery group. CONCLUSION: This study found that baseline localized pressure pain sensitivity and depression were predictive of long-term clinical outcomes in women with CTS following physical therapy or surgery, respectively.

Effects of local treatment with and without sensorimotor and balance exercise in individuals with neck pain: protocol for a randomized controlled trial.

BACKGROUND: Impaired cervical joint position sense and balance are associated with neck pain. Specific therapeutic exercise and manual therapy are effective for improving neck pain and functional ability but their effects on joint position sense and balance impairments remain uncertain. Changes in the joint position sense and balance may need to be addressed specifically. The primary objective is to investigate the most effective interventions to improve impaired cervical joint position sense and balance in individuals with neck pain. The secondary objective is to assess the effectiveness of the interventions on pain intensity and disability, pain location, dizziness symptoms, cervical range of motion, gait speed, functional ability, treatment satisfaction and quality of life. METHODS: A 2 × 2 factorial, single blind RCT with immediate, short- and long-term follow-ups. One hundred and sixty eight participants with neck pain with impaired joint position sense and balance will be recruited into the trial. Participants will be randomly allocated to one of four intervention groups: i) local neck treatment, ii) local treatment plus tailored sensorimotor exercises, iii) local treatment plus balance exercises, and iv) local treatment plus sensorimotor and balance exercises. Participants receive two treatments for 6 weeks. Primary outcomes are postural sway and cervical joint position error. Secondary outcomes include gait speed, dizziness intensity, neck pain intensity, neck disability, pain extent and location, cervical range of motion, functional ability, perceived benefit, and quality of life. Assessment will be measured at baseline, immediately after treatment and at 3, 6, 12 month-follow ups. DISCUSSION: Neck pain is one of the major causes of disability. Effective treatment must address not only the symptoms but the dysfunctions associated with neck pain. This trial will evaluate the effectiveness of interventions for individuals with neck pain with impaired cervical joint position sense and balance. This trial will impact on clinical practice by providing evidence towards optimal and efficient management. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT03149302 ). May 10, 2017.

Profiling the Location and Extent of Musicians' Pain Using Digital Pain Drawings.

BACKGROUND AND AIMS: According to existing literature, musicians are at risk of experiencing a range of painful musculoskeletal conditions. Recently, a novel digital technology was developed to investigate pain location and pain extent. The aim of this study was to describe pain location and pain extent in musicians using a digital method for pain drawing (PD) analysis. Additionally, the association between PD variables and clinical features were explored in musicians with pain. METHODS: One hundred and fifty-eight musicians (90 women and 68 men; aged 22.4 ± 3.6 years) were recruited from Swiss and U.K. conservatories. Participants were asked to complete a survey including both background musical information and clinical features, the QuickDASH (QD) questionnaire, and the digital PDs. RESULTS: Of the 158 participants, 126 musicians (79.7%) reported having pain, with higher prevalence in the areas of the neck and shoulders, the lower back, and the right arm. The mean percentage of pain extent was 3.1% ± 6.5%. The mean QD score was higher for musicians with pain than for those without pain. Additionally, the results indicated a positive correlation between the QD score and pain extent, and there were significant correlations between age and pain intensity, as well as between pain extent and pain intensity. CONCLUSIONS: The high prevalence of pain among musicians has been confirmed using a digital technique for PD acquisition and analysis. In addition, positive correlations between pain extent and upper limb disability have been demonstrated. Our findings highlight the need for effective prevention and treatment strategies for musicians.

Pain Extent Is Associated with the Emotional and Physical Burdens of Chronic Tension-Type Headache, but Not with Depression or Anxiety.

OBJECTIVE: Earlier studies suggest that pain extent, extracted from the patients' pain drawings, can help clinicians to identify people with central sensitization or worse clinical features. Our aim was to investigate possible associations between perceived pain extent and clinical pain features, burden of headache, psychological outcomes, and pressure sensitivity in people with chronic tension-type headache (CTTH). METHODS: Ninety-nine people (27% men) with CTTH reported their pain on four different body charts representing the head and neck. Pain extent and frequency maps were obtained using customized software. Clinical features of headache, burden related to headache (Headache Disability Inventory [HDI]), anxiety and depression (Hospital Anxiety-Depression Scale [HADS]), and anxiety state/trait (State-Trait Anxiety Inventory [STAI]) levels were assessed. Pressure pain thresholds (PPT) were assessed over the temporalis muscle (trigeminal area), the cervical spine (extratrigeminal area), and the tibialis anterior muscle (distant pain-free area) to determine widespread pressure sensitivity. Associations between pain extent and all outcomes were analyzed. RESULTS: Pain extent showed significant positive associations with age (r = 0.221, P = 0.029) and burden of the headache (emotional: r = 0.213, P = 0.030; physical: r = 0.208, P = 0.039), but no other significant association was found. CONCLUSIONS: Pain extent weakly correlated with older age as well as with higher emotional and physical burden of the headache in CTTH. In this population, there was no relationship between pain extent and PPT, indicating that larger pain areas were not associated with signs of central sensitization. Pain drawings can complement other clinical pain features for better characterization of CTTH, but further studies are needed.

Test-retest reliability of echo intensity parameters in healthy Achilles tendons using a semi-automatic tracing procedure.

OBJECTIVE: To evaluate the test-retest reliability of the ultrasound echo intensity parameters on healthy Achilles tendon using a semi-automatic tracing procedure. MATERIALS AND METHODS: Eighteen healthy volunteers participated. B-mode images were acquired in the transverse plane (mid-tendon; insertion) and used to analyze tendon echogenicity. Grayscale distribution of the pixels within the selected ROIs was represented as a histogram. Descriptive statistics of the grayscale distribution (mean, variance, skewness, kurtosis, and entropy) and parameters from the co-occurrence matrix (contrast, energy, and homogeneity) were calculated. RESULTS: Reliability of echo intensity parameters of the mid-Achilles tendon ranged from high to very high with an ICC2.k of 0.94 for echogenicity, 0.87 for variance, 0.80 for skewness, 0.72 for kurtosis, 0.89 for entropy, 0.90 for contrast, 0.91 for energy, and 0.93 for homogeneity, while for tendon insertion they ranged from moderate to high with an ICC2.k of 0.74 for echogenicity, 0.88 for variance, 0.75 for skewness, 0.55 for kurtosis, 0.87 for entropy, 0.70 for contrast, 0.77 for energy, and 0.56 for homogeneity. CONCLUSION: Ultrasound echo intensity is a reliable technique to characterize the internal structure of the Achilles tendon.

Test-retest Reliability in Reporting the Pain Induced by a Pain Provocation Test: Further Validation of a Novel Approach for Pain Drawing Acquisition and Analysis.

BACKGROUND: Pain drawings (PD) are frequently used in research to illustrate the pain response to pain provocation tests. However, there is a lack of data on the reliability in defining the extent and location of pain. We investigated the test-retest reliability in reporting an acute painful sensation induced by a pain provocation test using a novel approach for PD acquisition and analysis in healthy volunteers. METHODS: Forty healthy volunteers participated. Each participant underwent 2 upper limb neurodynamic tests 1 (ULNT1), once to the point of pain onset (PO) and once until the point of submaximal pain (SP). After each ULNT1, participants completed 2 consecutive PD with an interval of 1 minute. Custom software was used to quantify the pain extent and analyze the pain overlap. The test-retest reliability of pain extent was examined using Intraclass Correlation Coefficient (ICC 2,1 ) and Bland-Altman plots. Pain location reliability was examined using the Jaccard similarity coefficient (JSC). RESULTS: The ICC values for PO and SP were 0.98 (95% CI: 0.96-0.99) and 0.97 (95% CI: 0.95-0.98), respectively. The mean difference and 95% limits of agreement (± 1.96 SD) in the Bland-Altman plots were 14 pixels (-1080;1110) for PO, and 145 (-1610;1900) for SP. The median JSCs (Q1;Q3) were 0.73 (0.64;0.80) for PO and 0.76 (0.65;0.79) for SP. CONCLUSIONS: Pain drawings is a reliable instrument to investigate pain extent and pain location in healthy individuals experiencing an acute painful sensation induced by a pain provocation test.

Prevalence of Myofascial Trigger Points in Spinal Disorders: A Systematic Review and Meta-Analysis.

OBJECTIVE: To retrieve, appraise, and synthesize the results of studies on the prevalence of active and latent myofascial trigger points (MTrPs) in subjects with spinal pain disorders. DATA SOURCES: The databases PubMed, Embase, and CINAHL were searched, with no date or language restrictions. Search terms included controlled and free-text terms for spinal disorders and MTrPs. Further searches were conducted in Google Scholar and by contacting 3 experts in the field. Citation tracking of eligible studies was performed. STUDY SELECTION: Two reviewers independently selected observational studies assessing the prevalence of active and/or latent MTrPs in at least 1 group of adults with a spinal disorder. Twelve studies met the eligibility criteria. DATA EXTRACTION: Methodologic quality was assessed by 2 reviewers independently using a modified version of the Downs and Black checklist. Two reviewers also used a customized form to extract studies and subjects' characteristics and the proportions of subjects with active and/or latent MTrPs in each muscle assessed. DATA SYNTHESIS: A meta-analysis was performed when there was sufficient clinical homogeneity in at least 2 studies for the same spinal disorder. The Grading of Recommendations Assessment, Development and Evaluation approach was used to rate the body of evidence in each meta-analysis. A qualitative description of the results of single studies was provided. Low-quality evidence underpinned pooled estimates of MTrPs in the upper-body muscles of subjects with chronic neck pain. The point prevalence of MTrPs in different muscles of other disorders (eg, whiplash-associated disorders, nonspecific low back pain) was extracted from single studies with low methodologic quality and small samples. Active MTrPs were found to be present in all assessed muscles of subjects diagnosed with different spinal pain disorders. Latent MTrPs were not consistently more prevalent in subjects with a spinal disorder than in healthy controls. CONCLUSIONS: The MTrPs point prevalence estimates in this review should be viewed with caution because future studies with large samples and high methodologic quality are likely to change them substantially.

Real-time sonoelastography using an external reference material: test-retest reliability of healthy Achilles tendons.

OBJECTIVE: To establish the test-retest reliability of sonoelastography (SE) on healthy Achilles tendons in contracted and relaxed states using an external reference system. MATERIALS AND METHODS: Forty-eight Achilles tendons from 24 healthy volunteers were assessed using ultrasound and real-time SE with an external reference material. Tendons were analyzed under relaxed and contracted conditions. Strain ratios between the tendons and the reference material were calculated. The intraclass correlation coefficient (ICC2.k) and Bland-Altman plot were used to assess test-retest reliability. RESULTS: The reliability of SE measurements under relaxed conditions ranged from high to very high, with an ICC2.k of 0.84 (95 % CI: 0.64-0.92) for reference material, 0.91 (95 % CI: 0.83-0.95) for Achilles tendons and 0.95 (95 % CI: 0.91-0.97) for Kager fat pads (KFP). The ICC2.k value for skin was 0.30 (95 % CI: -0.26 to 0.61). Reliability for measurements in the contracted state ranged from high to very high, with an ICC2.k of 0.93 (95 % CI: 0.87-0.96) for reference material, 0.72 (95 % CI: 0.50-0.84) for skin, 0.93 (95 % CI: 0.87-0.96) for Achilles tendons, and 0.81 (95 % CI: 0.66-0.89) for KFP. Reliability of the strain ratio (tendon/reference) under relaxed conditions was high with an ICC2.k of 0.87 (95 % CI: 0.75-0.93), and in the contracted state, it was very high with an ICC2.k of 0.94 (95 % CI: 0.90-0.97). CONCLUSION: Sonoelastography using an external reference material is a reliable and simple technique for the assessment of the elasticity of healthy Achilles tendons. The use of an external material as a reference, along with strain ratios, could provide a quantitative measure of elasticity.