Central Pain Processing in Patients with Shoulder Pain: A Review of the Literature

The association between conditioned pain modulation and psychological factors in people with chronic spinal pain: A systematic review

Chronic spinal pain has negative effects on physical and mental well-being. Psychological factors can influence pain tolerance. However, whether these factors influence descending modulatory control mechanisms measured by conditioned pain modulation (CPM) in people with chronic spinal pain is unclear. This systematic review investigated the association between CPM response and psychological factors in people with chronic spinal pain. Published and unpublished literature databases were searched from inception to 23rd October 2023 included MEDLINE, EMBASE, CINAHL, and PubMed. Studies assessing the association between CPM response and psychological factors in people with chronic spinal pain were eligible. Data were pooled through meta-analysis. Methodological quality was assessed using the AXIS tool and the certainty of evidence measured through GRADE. From 2172 records, seven studies (n = 598) were eligible. Quality of included studies was moderate. There was very low certainty of evidence that depression (r = 0.01 [95% CI -0.10 to 0.12], I2 = 0%), and anxiety (r = -0.20 [95% CI -0.56 to 0.16], I2 = 84%), fear avoidance (r = -0.10 [95% CI -0.30 to 0.10], I2 = 70%) had no statistical associations with CPM responder status. Higher pain catastrophising was associated with CPM non-responder status (r = -0.19; 95% CI: -0.37 to -0.02; n = 545; I2: 76%) based on a very low certainty of evidence measured by GRADE. There is currently limited available evidence demonstrating an association between CPM response and psychological factors for people with chronic pain. Managing an individual's chronic pain symptoms irrespective of comorbid psychological distress, should continue until evidence offer insights that more targeted interventions are needed.

Psychosocial Factors, Sleep, and Central Pain Processing for Making a Prognosis About Recovery of Pain, Function, and Quality of Life After Rotator Cuff Repair: An Exploratory Longitudinal Study

OBJECTIVE: To explore modifiable psychosocial factors, sleep-related variables, indices of central pain processing and patients' characteristics as potential prognostic factors for pain, shoulder function, and quality of life (QoL) 1 year after rotator cuff repair. DESIGN: This observational longitudinal study included 142 patients who were undergoing rotator cuff repair. All measures took place pre-rotator cuff repair (T0), and 12 weeks (T1) and 12 months (T2) after rotator cuff repair. METHODS: Mixed-effects linear regression modeled relationships between the Western Ontario Rotator Cuff Index (WORC, model A), the Subjective Shoulder Value (SSV, model B), and EuroQol's EQ-5D-5L for QoL (model C), and potential prognostic factors over time. Factors included psychosocial variables, sleep-related indices, and proxies of central pain processing. Patients' age, sex, and body mass index complemented the analyses. RESULTS: At follow-up (T2), data from 124 participants were available for analysis. Five prognostic factors were identified for the 1-year outcome. Better expectations for symptom reduction (P<.0001, -1.4 mm) and an increase in Douleur Neuropathique 4 score (P = .0481, -0.9 mm) affected the evolution of WORC over time (model A). An increase in injury perception subscale consequence (P = .0035, 0.04%) influenced the SSV trajectory (model B). In addition, when sleep quality (P = .0011, -0.13%) and sleep efficiency (P = .0002, 0.005%) improved, the EQ-5D-5L slope was affected (model C). CONCLUSION: Addressing cognitions, pain mechanisms and sleep behavior prior to rotator cuff repair can identify people who are at risk of a poor outcome after surgery. J Orthop Sports Phys Ther 2024;54(8):530-540. Epub 4 July 2024. doi:10.2519/jospt.2024.12398.

Evaluation of the segmental distribution of pain sensitivity among patients with central sensitization associated with chronic subacromial pain syndrome: A cross-sectional study

INTRODUCTION

Pain sensitivity is the main finding of central sensitization (CS) and can occur in patients with chronic shoulder pain. However, there is limited evidence concerning the distribution of pain sensitivity in shoulders, forearms, and legs in patients with CS associated with chronic shoulder pain. The present study aimed to determine the distribution of pain sensitivity in patients with CS associated with chronic subacromial pain syndrome (SPS).

METHOD

This cross-sectional study included 58 patients with chronic SPS and CS (patient group) and 58 healthy participants (control group). The presence of CS was determined using the Central Sensitization Inventory (CSI). To determine the distribution of pain sensitivity, pressure pain threshold (PPT) measurements were performed from the shoulders, forearms, and legs.

RESULTS

There was no significant difference between the two groups in terms of sociodemographic data (p > 0.05). The patient group had a significantly higher CSI score (p < 0.001) and lower PPTs in all regions (p < 0.05) than the control group. Unlike the control group, the patient group had lower PPTs on the affected side for the shoulder [mean difference (MD) 95% confidence interval (CI): 1.2 (-1.7 to -0.6)], forearm [MD 95% CI: 1.1 (-1.7 to -0.6)], and leg [MD 95% CI: 0.9 (-1.4 to -0.3)] compared with the contralateral side (p < 0.001).

CONCLUSION

Pain sensitivity is more pronounced in the affected shoulder and the forearm and leg located on this side than in those on the contralateral side in patients with CS associated with chronic SPS.

Effectiveness of specific scapular therapeutic exercises in patients with shoulder pain: a systematic review with meta-analysis

Background

Therapeutic exercise has been considered a useful tool to rehabilitate shoulder pain, namely through its influence on scapular dynamics. Accordingly, the effectiveness of scapular therapeutic exercise needs to be explored. The present study aims to evaluate the effectiveness of scapular therapeutic exercises in shoulder pain and to identify the most effective exercise type (focal or multijoint) and ways of delivering them (as dose and progression).

Methods

Search was conducted at EMBASE, Cochrane Library, MEDLINE via PubMed, Web of Science, PEDro (Physiotherapy Evidence Database), and trial registration databases. The meta-analysis considered randomized controlled/crossover trials that compared the effect of scapular exercises against other types of intervention in the shoulder pain, shoulder function, scapular motion, and/or muscular activity. The risk of bias was assessed through the PEDro scale.

Results

From the 8318 records identified, 8 (high to low risk of bias- scoring from 4 to 8 on the PEDro scale) were included. The overall data, before sensitivity analysis, indicated that the scapular therapeutic exercises are: a) more effective than comparators in improving shoulder function (standardized mean difference [SMD] = 0.52 [95% Cl: 0.05, 0.99], P = .03, I2 = 76%); and b) as effective as comparators in reducing shoulder pain (SMD = 0.32 [95% Cl: -0.09, 0.73], P = .13, I2 = 70%). Subgroup analysis revealed that scapular exercises are more effective in improving shoulder function when the program duration is equal to or higher than 6 weeks (SMD = 0.43 [95% Cl: 0.09, 0.76] P = .01, I2 = 21%) and/or when the maximum number of exercise repetitions per session is lower than 30 (SMD = 0.79 [95% Cl: 0.15, 1.42], P = .01, I2 = 77%). Only 1 study considered scapular motion as an outcome measure, revealing therapeutic exercise effectiveness to improve scapular range of motion.

Conclusions

Intervention programs involving scapular therapeutic exercises are effective in improving shoulder function, presenting benefits when performed for 6 or more weeks and/or when used up to a maximum of 30 repetitions per exercise, per session.

Nitrous oxide provided during intensive physiotherapy for shoulder adhesive capsulitis does not improve function: A randomised controlled trial

BACKGROUND

There is no consensus on treatment for adhesive capsulitis of the shoulder. Physiotherapy is often used to increase range of motion but individuals may experience pain during mobilisation.

OBJECTIVES

The objective of this study was to determine whether rehabilitation under N2O for shoulder AC improved pain and function more than rehabilitation alone (with placebo gas).

METHOD

A randomised, 1:1 parallel arm, double-blind study in 4 university hospital outpatient centres. Adults with adhesive capsulitis for at least 3 months with intact cartilage were included. Participants were randomised in blocks of 4 and stratified by centre to receive 20 sessions of intensive physiotherapy over 10 days; the 10 morning sessions were performed with either nitrous oxide (intervention) or sham gas (placebo).

PRIMARY OUTCOME

improvement in shoulder function at day 14 (D14) (Constant-Murley score).

RESULTS

Seventy-five participants were included, and data from 69 were analysed: 37 in the placebo group and 32 in the intervention group. Improvements occurred in both groups after the intervention. No significant difference in the Constant-Murley score was found between groups at D14 (median score increase of 12.0, IQR 5.6; 19.5 points in placebo group vs. 13.7, 5.2; 18.2 in the N20 group, p = 0.78). Pain score during sessions reduced in the intervention group from the first to final session (-11.6, p = 0.053) but not for the placebo group (-4.2, p = 0.414). Seven serious adverse events were recorded, 4 in the intervention group and 3 in the placebo group, with 11 minor adverse events only in the intervention group (mostly shortness of breath).

CONCLUSION

Nitrous oxide gas associated with intensive physiotherapy for shoulder adhesive capsulitis did not improve function, pain or quality of life more than physiotherapy alone. zHowever, pain experienced during physiotherapy sessions appeared lower.

TRIAL REGISTRATION

Clinical Trial registration number NCT01087229.

Translation, cross-cultural adaptation, and measurement properties of the Arabic version of the pain sensitivity questionnaire

Background

The Pain Sensitivity Questionnaire (PSQ) is a reliable and valid self-reported tool for the assessment of pain sensitivity in clinical practice. The PSQ has been translated, validated, and cross-culturally adapted into multiple languages. However, a validated Arabic version of the PSQ is not available. Thus, this study aims to translate, validate, and cross-culturally adapt the English version of the PSQ into the Arabic language.

Methods and materials

The English version of the PSQ was translated and culturally adapted into Arabic following international guidelines. The psychometric properties of the final version of the PSQ-Arabic (PSQ-A) were tested among 119 patients with different persistent musculoskeletal (MSK) pain.

Findings

The Cronbach's α for the PSQ-A-total, PSQ-A-moderate, and PSQ-C-minor were 0.81, 0.79, and 0.76, respectively. The means for the PSQ-A-total, PSQ-A-moderate, and PSQ-C-minor scores were 5.07 (±1.28), 5.64 (±2.07), and 4.50 (±0.50). The test-retest reliability measured with the interclass correlation coefficient for 68 subjects was 0.80 for the PSQ-A-total, 0.74 for the PSQ-A-moderate, and 0.77 for the PSQ-A-minor. The PSQ-A-total and the PSQ-A-minor showed positive significant correlations with pain catastrophizing scale (PCS) (r = 0.15, 0.17); P ≤ 0.05), respectively. The PSQ-A-total, PSQ-A-moderate, and PSQ-A-minor showed positive significant correlations with the Brief Pain Inventory (BPI)-pain scores (r = 0.47, 0.43, 0.45; P ≤ 0.01), respectively and with the BPI-pain interference scores (r = 0.37, 0.33, 0.34; P ≤ 0.01), respectively.

Conclusions

This study shows that the PSQ-A is a reliable and valid tool to assess individuals with pain sensitivity in Arabic populations. Further studies are recommended to examine the concurrent validity of the PSQ-A against experimental pain sensitivity measures.

Hemiplegic shoulder pain affects ipsilesional aiming movements after stroke: a cross-sectional study

BACKGROUND

Hemiplegic shoulder pain (HSP) is common after stroke. The pain perception may exacerbate changes in the motor behavior of the ipsi-lesional upper limb, contributing to the functional decline of an individual's motor performance.

OBJECTIVE

This study evaluates the influence of pain perception on the aiming movements performed with the ipsilesional upper limb in individuals with unilateral chronic stroke.

METHODS

A cross-sectional study was conducted with 41 participants divided into three groups: 1) stroke with contralesional shoulder pain ≥ 3 by the Visual Numerical Pain Scale (SPSG; n = 13); 2) stroke no shoulder pain (nSPSG; n = 14); and 3) healthy control (CTG; n = 14) matched by sex and age. Individuals with stroke were matched for the severity of sensorimotor impairment by the Fugl-Meyer upper limb subscale and the injured hemisphere side. Stroke groups performed aiming movements with the ipsilesional upper limb and the CTG with the corresponding limb using a pen tip on the sensitive surface of a digitizing tablet. Performance across groups was compared by one-way analysis of variance, considering the time since injury as a covariate. The planning and execution variables of the movement trajectory were analyzed, and the significance was set at 5%.

RESULTS

Trajectories of the SPSG were slower (p = .010; η2 = 0.22), were less smooth (p = .002; η2 = 0.30), had more directional error (p = .002; η2 = 0.28), and were less accurate (p = .034; η2 = 0.17) than the CTG. The nSPSG and CTG showed similar performance.

CONCLUSIONS

The perception of pain impairs aiming movements performed with the ipsilesional upper limb in individuals with unilateral chronic stroke.

A retrospective examination of pain in acute stroke at hospital discharge

OBJECTIVES

Pain is an overlooked sequela of stroke. Persistent pain after stroke is an underrecognized experience and significantly impacts survivors' function, ability to participate in rehabilitation, and quality of life. The aim of this retrospective, observational study is to examine the incidence of pain at the acute hospitalization period immediately after stroke, to identify the characteristics of those reporting pain at discharge, and to compare pain reporting between stroke and non-stroke hospital controls.

MATERIALS AND METHODS

Using discharge diagnosis, this retrospective review examined self- reports of pain during acute hospitalization for stroke compared to those with COPD (control group) admitted during the same time in the same facilities. Variables of interest included age, gender, body mass index (BMI), length of stay, pain assessment score (numeric rating scale [NRS], behavior pain scale [BPS], and medication administration record pain score total [MAR]), smoking history, prevalence of hypertension and race. 821 subjects were included from a total of three campuses from one large hospital system. 772 subjects were included in the comparative analysis with COPD patients from the same facilities during the same time.

RESULTS

43% of patients diagnosed with stroke reported pain at discharge. For stroke survivors reporting pain at discharge, the average BMI was higher (p=0.009), average arrival NIHSS was higher (p=0.044), and mean hospital length of stay was longer (p<0.001).

CONCLUSIONS

The evidence demonstrated in this study highlights the critical need for the implementation of targeted objective pain assessment and effective pain interventions for stroke survivors beginning at initial hospitalization.

Exploration of the clinical course and longitudinal correlations in frozen shoulder: The role of autonomic function, central pain processing, and psychological variables. A longitudinal multicenter prospective observational study

BACKGROUND

Altered central pain processing (CPP) and dysautonomia might play a role in the clinical course of frozen shoulder and psychological factors, like pain catastrophizing and hypervigilance, might influence clinical variables in frozen shoulder.

OBJECTIVES

To explore the clinical course of frozen shoulder regarding CPP, dysautonomia, pain catastrophizing, and hypervigilance and to explore whether longitudinal correlations between these outcomes and pain intensity were present.

DESIGN

prospective longitudinal observational study.

METHOD

Participants with frozen shoulder were recruited at hospitals and general practitioner practices and followed for 9 months. They completed six questionnaires (about demographics, shoulder pain and disability, pain intensity, pain catastrophizing, pain hypervigilance, and autonomic symptoms) and underwent tactile sensitivity (allodynia), pressure pain thresholds (hyperalgesia), temporal summation, and conditioned pain modulation during four timeframes (3-month intervals).

RESULTS

Initially, 149 participants with frozen shoulder were recruited and 88 completed all the measurements. An improvement from baseline to at least one follow-up measurement was found for shoulder pain and disability, pain intensity, pain catastrophizing, hypervigilance, and dysautonomia. A fair longitudinal correlation was found between pain intensity and catastrophizing and hypervigilance (r = 0.301-0.397). Poor longitudinal correlations were found between pain intensity and allodynia and hyperalgesia (r = -0.180-0.193), between pain catastrophizing and dysautonomia (r = 0.209) and between hypervigilance and hyperalgesia (r = -0.159).

CONCLUSION

Patients with frozen shoulder showed an early improvement that flattened with time in several pain and psychological variables over the course of 9 months. However, autonomic symptoms rather showed a late improvement over 9 months.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Are clinical outcomes associated with baseline sensory profiles in people with musculoskeletal shoulder pain? Protocol for a prospective longitudinal observational study

BACKGROUND

Musculoskeletal shoulder pain is a common problem and its symptoms often become persistent. The experience of pain is multidimensional, and therefore, a range of patient characteristics may influence treatment response. An altered sensory processing has been associated with persistent musculoskeletal pain states and may contribute to outcomes in patients with musculoskeletal shoulder pain. The presence and potential impact of altered sensory processing in this patient cohort is not currently known. The aim of this prospective longitudinal cohort study is to investigate if baseline sensory characteristics are associated with clinical outcomes in patients presenting to a tertiary hospital with persistent musculoskeletal shoulder pain. If found, a relationship between sensory characteristics and outcome may lead to the creation of more effective treatment strategies and improvements in risk adjustment and prognosis.

METHODS

This is a single-centre prospective cohort study with 6-, 12- and 24-month follow-up. A total of 120 participants aged ≥18 years with persistent musculoskeletal shoulder pain (≥3 months) will be recruited from an Australian public tertiary hospital orthopaedic department. Baseline assessments, including quantitative sensory tests and a standardised physical examination, will be performed. In addition, information will be obtained from patient interviews, self-report questionnaires and medical records. Follow-up outcome measures will comprise information from the Shoulder Pain and Disability Index and a six-point Global Rating of Change scale.

ANALYSIS

Descriptive statistics will be used to report baseline characteristics and outcome measures over time. Change in outcome measures at the primary endpoint of six months from baseline will be calculated using paired t-tests. Associations between baseline characteristics and outcomes at a 6-month follow-up will be reported using multivariable linear and logistic regression models.

DISCUSSION

Understanding the relationship between sensory profile and the variable response to treatment in people with persistent musculoskeletal shoulder pain may enhance our understanding of the mechanisms contributing to the presentation. In addition, through better understanding of the contributing factors, the results of this study may contribute to the development of an individualised, patient-centred approach to treatment for people with this highly prevalent and debilitating condition.

Central sensitization syndrome in patients with rotator cuff tear: prevalence and associated factors

INTRODUCTION

A significant number of rotator cuff tear (RCT) patients developed chronic shoulder pain that did not correspond to physiological changes. Central sensitization syndrome (CSS) is a neurophysiological adaptation process that can result in hypersensitivity to peripheral stimuli. Although there is evidence of an association between CSS and musculoskeletal problems, no studies have focused on the association between CSS and RCT. The primary purpose of this study was to examine the prevalence of CSS in patients with RCT. The secondary purpose was to document the associated conditions and comorbidity that were associated with the CSS.

METHODS

This was a cross-sectional study of patients with RCT who completed the Central Sensitization Inventory (CSI). Patients with score of ≥ 40/100 were considered positive for CSS. Demographic and clinical data and CSI results were collected to analyze the prevalence and associated factors of CSS in RCT patients.

RESULTS

A total of 404 RCT patients were included, and the CSS prevalence was 39.4%. Compared to the non-CSS group, the CSS group had an odds ratio of 4.13 (95% CI, 2.70-6.32; p＜0.001) for ages 51-60, 3.07 (95% CI, 2.00-4.69; p＜0.001) for symptoms lasting more than 6 months, 6.08 (95% CI, 3.90-9.47; p＜0.001) for nonphysical laborers, 3.69 (95%CI, 2.42-5.61; p＜0.001) for long head of biceps (LHB) abnormality, 2.93 (95% CI, 1.93-4.45; p＜0.001) for concurrent shoulder stiffness, 4.82 (95% CI, 2.55-9.10; p＜0.001) for anxiety or panic episodes, and 2.11 (95% CI, 1.12, 4.00; p＜0.001) for depression.

CONCLUSIONS

The prevalence of CSS in patients with RCT was relatively high at 39.4%. The CSS was associated with higher age, female gender, and clinical findings of symptoms lasting over six months, nonphysical laborers, abnormal LHB, concurrent shoulder stiffness, anxiety, and depression.

Finite element study of the biomechanical effects on the rotator cuff under load

Rotator cuff injuries account for 50% of shoulder disorders that can cause shoulder pain and reduced mobility. The occurrence of rotator cuff injury is related to the variation in shoulder load, but the mechanical changes in the rotator cuff caused by load remain unclear. Therefore, the mechanical results of the rotator cuff tissue during glenohumeral abduction and adduction were analyzed based on a finite element shoulder model under non-load (0 kg) and load (7.5 kg) conditions. The results showed that the maximum von Mises stress on the supraspinatus muscle was larger than that on the subscapularis, infraspinatus, and teres minor muscles during glenohumeral abduction. Compared with the non-load condition, the maximum von Mises stress on the supraspinatus muscle increased by 75% under the load condition at 30° abduction. Under the load condition, the supraspinatus joint side exhibited an average stress that was 32% greater than that observed on the bursal side. The von Mises stress on the infraspinatus muscle was higher than that in other rotator cuff tissues during adduction. The stress on the infraspinatus muscle increased by 36% in the load condition compared to the non-load condition at 30° adduction. In summary, the increased load changed the mechanical distribution of rotator cuff tissue and increased the stress differential between the joint aspect and the bursal aspect of the supraspinatus tendon.

Exercise for rotator cuff tendinopathy: Proposed mechanisms of recovery

Rotator cuff (RC) tendinopathy is a common recurrent cause of shoulder pain, and resistance exercise is the first-line recommended intervention. Proposed causal mechanisms of resistance exercise for patients with RC tendinopathy consist of four domains: tendon structure, neuromuscular factors, pain and sensorimotor processing, and psychosocial factors. Tendon structure plays a role in RC tendinopathy, with decreased stiffness, increased thickness, and collagen disorganization. Neuromuscular performance deficits of altered kinematics, muscle activation, and force are present in RC tendinopathy, but advanced methods of assessing muscle performance are needed to fully assess these factors. Psychological factors of depression, anxiety, pain catastrophizing, treatment expectations, and self-efficacy are present and predict patient-reported outcomes. Central nervous system dysfunctions also exist, specifically altered pain and sensorimotor processing. Resisted exercise may normalize these factors, but limited evidence exists to explain the relationship of the four proposed domains to trajectory of recovery and defining persistent deficits limiting outcomes. Clinicians and researchers can use this model to understand how exercise mediates change in patient outcomes, develop subgroups to deliver patient-specific approach for treatment and define metrics to track recovery over time. Supporting evidence is limited, indicating the need for future studies characterizing mechanisms of recovery with exercise for RC tendinopathy.

The Neurophysiological Lesion: A Scoping Review

Objective

The purpose of this study was to examine the extent of the literature on the neurophysiological lesion as referenced in functional neurology.

Methods

A literature search was performed within the period from 2010 to March 2021. Search terms included central sensitization, central sensitivity syndrome, nociplastic pain, cold hyperalgesia, heat hyperalgesia, mechanical hyperalgesia, dynamic mechanical allodynia, temporal summation, spatial summation, and descending inhibition. A qualitative synthesis summarized the research findings, including clinical conditions and effect of spinal manipulation.

Results

There were 30 studies, which included 7 high-level studies (meta-analysis or systematic reviews), 22 randomized controlled studies, and 1 scoping review. The findings suggest the existence of the changes in the central integrated state of a population of neurons with various disorders, experimentally induced stimulation, and treatment. The current literature suggests plasticity of the central integrative state (CIS) with the onset of pathologies and the changes in the CIS with different conservative nonpharmacologic treatments.

Conclusions

This review suggests changes in the resting state of the CIS of a population of neurons that exist in the physiologic lesion may change in response to various therapies, including manipulative therapy. The findings from this review provide support of the hypothesis that nonpharmacologic conservative care may affect the neurophysiological lesion. However, studies were heterogeneous and evidence was lacking in the translation of targeting the therapies to distinct neuronal areas for clinical outcomes to treat specific disease states.

Sensitivity to movement-evoked pain, central sensitivity symptoms, and pro-nociceptive profiles in people with chronic shoulder pain: A parallel-group cross-sectional investigation

OBJECTIVE

To investigate whether sensitivity to movement-evoked pain (SMEP), central sensitivity symptom burden, and quantitative sensory testing (QST) outcomes differ between healthy controls and people with chronic shoulder pain.

METHODS

People with chronic shoulder pain (n = 39) and healthy controls (n = 26) completed validated questionnaires measuring demographic, pain characteristics, psychological factors, social support, sleep quality, central sensitivity inventory (CSI), and physical activity levels. A blinded assessor administered QST measuring pressure pain threshold, temporal summation, conditioned pain modulation, and cold hyperalgesia. All participants performed repeated lifting of weighted canisters and reported severity of pain over successive lifts of the weighted canisters. Between-group differences in the QST, SMEP and CSI scores were investigated. Demographic and psychosocial variables were adjusted in the analyses.

RESULTS

Dynamic mechanical allodynia, mechanical temporal summation, movement-evoked pain scores, SMEP index, and CSI scores were significantly (p ≤ 0.05) higher in the chronic shoulder pain group than in healthy controls. A significant proportion of people with chronic shoulder pain presented with pro-nociceptive profiles and experienced higher pain severity, interference, and disability.

CONCLUSIONS

People with chronic shoulder pain displayed symptoms and signs of central sensitization. Future research should investigate the predictive role of central sensitization on clinical outcomes in shoulder pain.

Autonomic Nervous System Function and Central Pain Processing in People With Frozen Shoulder: A Case-control Study

OBJECTIVES

The pathophysiology of a frozen shoulder (FS) is thought to be related to chronic inflammation. Chronic inflammation may disturb the immune system and consequently the nervous system as part of an overarching system. The aim of this study was to determine the presence of disturbed autonomic nervous system function and altered central pain processing (CPP) in patients with FS. Secondarily, the presence of psychological variables (catastrophizing and hypervigilance) and self-reported associated symptoms of altered CPP in patients with FS were investigated.

METHODS

Patients with FS and healthy controls completed the Composite Autonomic Symptom Score (autonomic function) and underwent quantitative sensory testing to assess tactile sensitivity (ie, allodynia), pressure pain thresholds (PPTs, ie, hyperalgesia), temporal summation of pain, and Conditioned Pain Modulation (CPM). Psychological issues were explored with the Pain Catastrophizing Scale and the Pain Vigilance and Awareness Questionnaire, and self-reported symptoms associated with altered CPP were determined with the Central Sensitization Inventory.

RESULTS

Thirty-two patients with FS and 35 healthy controls were analyzed in the study. Patients with FS showed more self-reported autonomic symptoms and symptoms of altered CPP, higher levels of pain catastrophizing and hypervigilance, and are more sensitive to tactile touches and mechanical pressure compared with controls.

DISCUSSION

On the basis of the effect sizes, between-group differences in allodynia, hyperalgesia, catastrophizing, and hypervigilance were clinically relevant, but only local allodynia, hyperalgesia, catastrophizing, and hypervigilance were statistically different. Therefore, obvious altered CPP was not present at the group level in patients with FS compared with controls.

Frozen shoulder

Frozen shoulder is a common debilitating disorder characterized by shoulder pain and progressive loss of shoulder movement. Frozen shoulder is frequently associated with other systemic conditions or occurs following periods of immobilization, and has a protracted clinical course, which can be frustrating for patients as well as health-care professionals. Frozen shoulder is characterized by fibroproliferative tissue fibrosis, whereby fibroblasts, producing predominantly type I and type III collagen, transform into myofibroblasts (a smooth muscle phenotype), which is accompanied by inflammation, neoangiogenesis and neoinnervation, resulting in shoulder capsular fibrotic contractures and the associated clinical stiffness. Diagnosis is heavily based on physical examination and can be difficult depending on the stage of disease or if concomitant shoulder pathology is present. Management consists of physiotherapy, therapeutic modalities such as steroid injections, anti-inflammatory medications, hydrodilation and surgical interventions; however, their effectiveness remains unclear. Facilitating translational science should aid in development of novel therapies to improve outcomes among individuals with this debilitating condition.

Convergent Validity of the Central Sensitization Inventory in Women with Fibromyalgia: Association with Clinical, Psychological and Psychophysical Outcomes

BACKGROUND

To assess the relationship between demographic, clinical, psychological, and pressure pain sensitivity outcomes with the central sensitization inventory (CSI) in female with fibromyalgia (FMS).

METHODS

One hundred twenty-six (n=126) females with FMS completed demographic (age, body mass index, height, weight), clinical (pain history, pain intensity at rest and during daily living activities), psychological (depression/anxiety levels) outcomes and widespread pressure pain sensitivity as well as the central sensitization inventory (CSI). After conducting a multivariable correlation analysis to identify the association between variables, a multiple linear regression model was performed to identify CSI predictors.

RESULTS

The CSI was negatively associated with age (r=-0.262) and PPTs (r ranged from -0.221 to -0.372) and positively associated with anxiety (r=0.541), depression (r=0.415), mean intensity (r=0.305), worst pain (r=0.249), and pain during daily living activities (r= 0.398). The stepwise regression analysis revealed that 47.4% of CSI variance in this sample was explained by anxiety levels (27.8%), PPT at greater trochanter (10.5%), age (1.4%), years with pain (4.8%) and pain during daily living activities (2.9%).

CONCLUSION

The current study found that age, pain intensity at rest and pain during daily living activities, anxiety levels, and pressure pain sensitivity are associated with the CSI (associated sensitization symptoms) in women with FMS.

Are psychosocial variables, sleep characteristics or central pain processing prognostic factors for outcome following rotator cuff repair? A protocol for a prospective longitudinal cohort study

INTRODUCTION

Prognosis following surgical rotator cuff repair (RCR) is often established through the assessment of non-modifiable biomedical factors such as tear size. This understates the complex nature of recovery following RCR. There is a need to identify modifiable psychosocial and sleep-related variables, and to find out whether changes in central pain processing influence prognosis after RCR. This will improve our knowledge on how to optimise recovery, using a holistic rehabilitation approach.

METHODS AND ANALYSIS

This longitudinal study will analyse 141 participants undergoing usual care for first time RCR. Data will be collected 1-21 days preoperatively (T1), then 11-14 weeks (T2) and 12-14 months (T3) postoperatively. We will use mixed-effects linear regression to assess relationships between potential prognostic factors and our primary and secondary outcome measures-the Western Ontario Rotator Cuff Index; the Constant-Murley Score; the Subjective Shoulder Value; Maximal Pain (Numeric Rating Scale); and Quality of Life (European Quality of Life, 5 dimensions, 5 levels). Potential prognostic factors include: four psychosocial variables; pain catastrophising, perceived stress, injury perceptions and patients' expectations for RCR; sleep; and four factors related to central pain processing (central sensitisation inventory, temporal summation, cold hyperalgesia and pressure pain threshold). Intercorrelations will be assessed to determine the strength of relationships between all potential prognostic indicators.Our aim is to explore whether modifiable psychosocial factors, sleep-related variables and altered central pain processing are associated with outcomes pre-RCR and post-RCR and to identify them as potential prognostic factors.

ETHICS AND DISSEMINATION

The results of the study will be disseminated at conferences such as the European Pain Congress. One or more manuscripts will be published in a peer-reviewed SCI-ranked journal. Findings will be reported in accordance with the STROBE statement and PROGRESS framework. Ethical approval is granted by the Ethical commission of Canton of Zurich, Switzerland, No: ID_2018-02089 TRIAL REGISTRATION NUMBER: NCT04946149.

Post-surgical physiotherapy in frozen shoulder: A review

Despite its prevalence, the optimal management of frozen shoulder is unclear. A range of conservative measures are often undertaken with varying degrees of success. In cases of severe and persistent symptoms, release procedures which could include any combination of manipulation under anaesthetic, arthroscopic capsular release or hydrodilatation are frequently offered, none of which has been shown to offer superior outcome over the others. When surgical release is performed a period of rehabilitation is normally recommended but no best practice guidelines exist resulting in considerable variations in practice which may or may not directly affect patient outcome. During this narrative review, we hypothesise that these differing responses to treatment (both conservative and surgical options) are potentially the result of different causal mechanisms for frozen shoulder and may also suggest that post-release rehabilitation may need to take this into account.

An interexaminer agreement and reliability study on cadavers with musculoskeletal ultrasound of the shoulder performed by physiotherapists and radiologists compared with dissection

STUDY DESIGN

A cross-sectional inter-examiner agreement and reliability study on fresh frozen cadaver shoulders.

BACKGROUND

Musculoskeletal ultrasound (MSU) is frequently used by physical therapists and radiologists to improve specific diagnosis in rotator cuff related pathology. The evaluation of the rotator cable seems to be important as stabilizing structure when cuff tears occur.

OBJECTIVES

To evaluate the inter-examiner agreement and reliability of MSU of the shoulder to detect rotator cuff-pathology and the involvement of the rotator cable in comparison to "dissection".

METHODS

Physical therapists, a radiologist and an orthopedic surgeon (dissection) investigated 40 fresh frozen cadaver shoulders in order to detect shoulder pathology including rotator cable involvement. Examiners were blinded to each other's findings.

RESULTS

We found a strong and significant agreement between the raters: PTs, the radiologist and the dissector in this cadaver study for all rotator cuff, the long head of the biceps pathologies and in detecting abnormalities of the rotator cable. The kappa value was substantial to (almost) perfect agreement for all diagnostic outcome categories.

CONCLUSIONS

This study shows that among a limited group of physical therapists, one radiologist and a dissector a strong level of agreement with kappa values from substantial to (almost) perfect in finding subacromial pathology.

Investigating the effects of mobilization with movement and exercise on pain modulation processes in shoulder pain - a single cohort pilot study with short-term follow up

OBJECTIVE

To explore the association between manual therapy and exercise and pain modulation and clinical characteristics in people with musculoskeletal shoulder pain.

METHODS

This is a prospective, longitudinal, single cohort pilot study. People with shoulder pain for longer than 6 weeks underwent 4 weeks of glenohumeral mobilization with movement and shoulder exercises. Measures of pain modulation, shoulder pain, disability, range of motion and psychosocial factors were assessed at baseline and immediately after the 4-week period of treatment. Treatment effectiveness was assessed through parametric, non-parametric and multilevel modeling statistics.

RESULTS

Twenty-three individuals participatedwith no loss to follow-up. Significant and meaningful improvements in shoulder pain (NRS mean change 1.6/10, 95% CI 0.4 to 2.7), disability (SPADI mean change 20.5/100, 95% CI 13.1 to 27.9) and range of motion (mean change 33°, 95% CI 23 to 43°) were observed following treatment. Statistical but non-clinically meaningful changes were observed in temporal summation of pain (mean change 0.3/10, 95% CI 0.1 to 0.4) and anxiety (mean change 0.86/21, 95% CI 0.18 to 1.55). Significant reductions were observed in temporal summation of pain (mean change 0.3/10, 95% CI 0.1 to 0.4) and anxiety (mean change 0.86/21, 95% CI 0.18 to 1.55), however these were not considered clinically important. No association was found between clinical characteristics and sensory measures. No association was found between clinical characteristics and sensory measures.

CONCLUSION

Glenohumeral mobilization with movement and exercise did not improve pain modulation, despite improvements in pain, function and range of motion, in people with shoulder pain.

Motor alterations in the kinetic chain in individuals with chronic shoulder pain

BACKGROUND

Shoulder pain may be related to biomechanical dysfunctions in the kinetic chain.

OBJECTIVE

To compare the mobility and muscular endurance of thoracolumbar spine and hip, and the neuromuscular control of the lower extremity of individuals with and without shoulder pain and to determine the discriminative capacity between groups of these variables.

DESIGN

A cross-sectional study.

METHOD

One hundred and two individuals with and without shoulder pain were evaluated to range of motion (ROM) of the thoracolumbar spine and hips, the muscular endurance time of the thoracolumbar spine and hips muscles, and the neuromuscular control of the lower extremity, by the Star Excursion Balance Test (SEBT).

RESULTS

Individuals with shoulder pain presented lower ROM and muscular endurance time in all tests evaluated (p < 0.01-p = 0.03), greater perception of pain during all ROM and muscle endurance (p < 0.01-p = 0.04) evaluations, and less neuromuscular control of the lower extremity in the compound reach (p < 0.01-p = 0.01), anterior and posteromedial (p < 0.01-p = 0.04) directions of the SEBT on both sides. The anterior reach direction of the SEBT of the contralateral limb to the shoulder pain (AUC=0.80, cut-off point=47.7%) presented excellent capacity to discriminate individuals with shoulder pain, while the other variables showed between acceptable and small capacity (AUC=0.58-0.76).

CONCLUSION

Individuals with chronic shoulder pain presented alterations in joint mobility, muscular endurance time of the thoracolumbar spine and hips and neuromuscular control of the lower extremity. The anterior reach of the SEBT of the contralateral limb showed excellent discriminative capacity.

A Central Nervous System Focused Treatment Program for People with Frozen Shoulder: A Feasibility Study

Background: Frozen shoulder (FS) is a highly disabling pathology of poorly understood etiology, which is characterized by the presence of intense pain and progressive loss of range of motion (ROM). The aim of this study is to evaluate the feasibility and clinical impact of a CNS-focused treatment program for people with FS. Methods: 10 subjects with primary FS received a 10-week CNS-focused intervention including sensory discrimination training and graded motor imagery techniques delivered as clinic sessions (60 min) and home therapy (30 min five times per week). Measurements were taken at baseline, after a 2-week “washout” period, after treatment, and at three months follow-up. The Shoulder Pain and Disability Index (SPADI) was the primary outcome. Secondary measures were feasibility-related outcomes, self-reported shoulder pain, active and passive range of motion, two-point discrimination threshold (TPDT), left/right judgement task (LRJT), fear-avoidance (Tampa Scale for Kinesiophobia), pain catastrophization (Pain Catastrophizing Scale), and pain sensitization (Central Sensitization Inventory). A Student’s t-test was used to assess the “washout” period. A repeated measure analysis of variance (ANOVA) was used to evaluate within-subjects’ differences for all outcome measures in the different assessment periods and a pairwise analysis was used to compare between the different assessment points. Statistical significance was set at p < 0.05. Results: 70% of participants completed the treatment. No significant changes were found after “washout” period except for TPDT (p = 0.02) and SPADI (p = 0.025). Improvements in self-reported shoulder pain (p = 0.028) and active shoulder flexion (p = 0.016) were shown after treatment (p = 0.028) and follow-up (p = 0.001) and in SPADI at follow-up (p = 0.008). No significant changes were observed in TPDT, LRJT, fear-avoidance, pain catastrophization, and pain sensitization. Conclusions: a CNS-focused treatment program might be a suitable approach to improve pain and disability in FS, but further research is needed to draw firm conclusions.

Use of the painDETECT to discriminate musculoskeletal pain phenotypes

Background

Musculoskeletal pain patients present similar pain characteristics regardless of the clinical diagnosis. PainDETECT questionnaire is useful for screening neuropathic-like symptoms in many musculoskeletal conditions. However, no previous studies compared pain phenotypes of patients with musculoskeletal pain using the painDETECT. Therefore, the current study aimed to compare the pain characteristics of patients with musculoskeletal pain classified according to the painDETECT as nociceptive pain, unclear, and neuropathic-like symptoms.

Methods

A cross-sectional study was conducted in 308 participants with musculoskeletal pain. Demographic and clinical characteristics of the participants were examined. Neuropathic-like symptoms, pain intensity, pain area, Central Sensitization-related sign and symptoms, functional limitation, and conditioned pain modulation were assessed in patients with musculoskeletal pain. Independent one-way analysis of variance (ANOVA) was used to test for between-group differences for the outcome measures with continuous variables and Pearson chi-square test verified between-group differences on the efficiency of the conditioned pain modulation.

Results

Participants had a mean age of 52.21 (±15.01) years old and 220 (71.42%) were females. One hundred seventy-three (56.16%) participants present nociceptive pain, 69 (22.40%) unclear, and 66 (21.42%) neuropathic-like symptoms. A one-way ANOVA showed differences for the pain intensity [F (2,305) = 20.097; p < .001], pain area [F (2,305) = 28.525; p < .001], Central Sensitization-related sign and symptoms [F (2,305) = 54.186; p < .001], and functional limitation [F (2,256) = 8.061; p < .001]. However, conditioned pain modulation was similarly impaired among the three groups (X² = 0.333, p = 0.847).

Conclusion

Patients with neuropathic-like symptoms revealed unfavorable pain characteristics compared to their counterparts, including pain intensity, generalized pain, Central Sensitization-related sign and symptoms, and functional limitation.

Shoulder pain across more movements is not related to more rotator cuff tendon findings in people with chronic shoulder pain diagnosed with subacromial pain syndrome

Supplemental Digital Content is Available in the Text. Neither the number nor severity of rotator cuff tendons reported as abnormal was associated with the pain occurrence across clinically relevant arm movements.

Introduction:

People with chronic shoulder pain commonly report pain during arm movements in daily-life activities. Pain related to movement is commonly viewed as an accurate representation of tissue damage. Thus, when a person reports pain across a variety of movements, this is often understood as indicative of greater damage.

Objectives:

We aimed to investigate if movement-related pain that occurs across a wider variety of movements was associated with the number or severity of rotator cuff tendons reported as abnormal on a magnetic resonance imaging (MRI). To answer this question, this study was designed in 3 phases.

Methods:

We recruited 130 individuals with chronic shoulder pain diagnosed with subacromial pain syndrome. First, a list of daily functional activities commonly reported as painful by people with chronic shoulder pain was generated from 3 well-established outcome measures with 30 individuals and a measurement tool was developed with data from further 100 individuals, which demonstrated to have acceptable content validity, construct validity, internal consistency, interrater reliability, and structural validity. Multiple linear regression was then used to evaluate the hypotheses of the study. A direct acyclic graph was used to select variables for linear regression modelling.

Results:

There was no association between movement-related pain occurrence across movements and the MRI findings.

Conclusion:

Our study provides evidence that neither the number of rotator cuff tendons reported as abnormal nor the severity of each tendon imaging finding were associated with pain occurrence across movements and activities commonly perceived as painful by people with chronic shoulder pain.

Is Shoulder Pain and Disability Index a Prognostic Factor for Neuropathic Shoulder Pain?

Introduction

So far, investigations in patients with rotator cuff diseases have used pain measurement tools such as visual analog scale (VAS) for nociceptive pain as well as neuropathic pain (NeuP) specialized ones like Douleur Neuropathique 4 Question (DN4) and Pain Detect. The study’s goal was to look at the existence of NeuP in patients with chronic shoulder pain, as well as variables that may be predictive of its progression.

Methods

There were 112 outpatients in all. Current and previous pain intensity levels were documented with the numerical rating scale (NRS), the Shoulder Pain and Disability Index (SPADI) was used to assess pain and disability levels, and the S-LANSS (self-completed Leeds Assessment of Neuropathic Symptoms and Signs Pain Scale) was used to diagnose NeuP. The Pearson Chi-Square test was employed to check for any relationships between variables. The Mann-Whitney U test was also employed to check for between-group differences (with or without NeuP). To investigate factors that may be utilized as a prognostic for NeuP, logistic regression was performed, with those components (from the univariate analysis) that were statistically significant being included.

Results

According to the S-LANSS questionnaire for NeuP diagnosis, 21 patients had NeuP. According to S-LANSS, chi-square test findings revealed that NeuP is independent of sex, smoking, size, and location or rotator cuff tear. Univariate analysis with Mann-Whitney U test revealed statistically significant differences in SPADI and NRS scores between the two patient groups (p < 0.001). Α multivariate analysis using S-LANSS as the binary dependent variable and NRS currently, NRS average last month and SPADI total score as independent variables (with statistical significance) revealed that total SPADI score may be considered as an independent prognostic factor for NeuP (odds ratio = 1.189, p < 0.001).

Limitations

Due to the limited number of patients who participated in the study, the findings were deemed insufficient in terms of statistical power. In particular, the power analysis of the study (type I error probability being [a] = .05) was less than 80% (for the total SPADI score), hence relatively small. As a result, there is a limited probability of a type I error.

Conclusions

Using S-LANSS, we discovered that 18.8% of patients with rotator cuff tears had NeuP. The SPADI scores (pain and disability) in the NeuP group were substantially greater than in the nociceptive pain group. As previous studies have suggested utilizing certain levels of the VAS for pain assessment and specialized questionnaires for NeuP evaluation, we recommend that SPADI be included as a tool for emphasizing the neuropathic features of shoulder pain.

Herzratenvariabilitätsbasiertes Lifestyle-Coaching bei Patient*innen mit subakromialem Schmerzsyndrom – eine Pilotstudie

Hintergrund Mehrere Studien konnten einen Einfluss von psychologischem Stress auf Schmerzmodulation und Wundheilung aufzeigen. Die Erweiterung der physiotherapeutischen Behandlung um die psychosoziale Ebene des biopsychosozialen Modells stellt komplexe Anforderungen an die behandelnden Physioherapeut*innen.

Ziel Untersucht wurde der Einfluss von auf Herzratenvariabilität (HRV) basierendem Lifestyle-Coaching auf die Entwicklung der funktionellen Einschränkungen und das Schmerzempfinden bei Patient*innen mit subakromialem Schmerzsyndrom (SAPS). Es erfolgte zudem eine Analyse der Machbarkeit für Folgestudien.

Methode 15 Proband*innen mit SAPS wurden randomisiert in 2 Gruppen eingeteilt. Die Interventionsgruppe erhielt zusätzlich zu der in beiden Gruppen durchgeführten übungstherapeutischen Intervention ein Lifestyle-Coaching. Als Kontrollparameter wurden der SPADI-Score (SPADI), das maximale Schmerzempfinden (NRSmax) und anhand der Kurzzeit-HRV-Messung die High Frequency (HF), Low Frequency (LF), LF/HF-Ratio, Root Mean Square of Successive Difference (Rmssd) sowie die Standard Deviation NN (SdNN) erhoben. Bezüglich der Machbarkeit wurden mögliche Störfaktoren, Optimierungsmöglichkeiten und eine adäquate Stichprobengröße eruiert.

Ergebnisse Einen signifikanten Unterschied zeigten die Variablen des SPADI-Scores, SPADI (95 % CI –59,3 bis –4,6; p = 0,026; d = –1,5), NRSmax (95 % CI –5,5 bis –0,1; p = 0,042; d = –1,35) und der HRV-Messwert HF (95 % CI 505,3–1753,3; p = 0,002; d = 2,23) im Vergleich zur Kontrollgruppe.

Schlussfolgerung Das Design dieser Studie ist machbar und für Folgestudien mit größeren Stichproben geeignet. Anpassungen bei der Randomisierung sowie den verwendeten Assessments sollten dabei vorgenommen werden. Für eine gültige Aussagekraft der Ergebnisse wurde die dafür nötige Stichprobengröße mit n = 66 ermittelt. Die Auswertung der klinischen Parameter weisen auf eine Steigerung der parasympathischen Aktivität (HF) sowie einer Reduktion von SPADI und NRSmax hin. Letztere können hierbei als potentiell positive Wirkung auf die Funktion und Schmerzreduktion in der Interventionsgruppe eingeschätzt werden.

Evidence of Bilateral Localized, but Not Widespread, Pressure Pain Hypersensitivity in Patients With Upper Extremity Tendinopathy/Overuse Injury: A Systematic Review and Meta-Analysis

OBJECTIVE

The presence of altered nociceptive pain processing in patients with upper extremity tendinopathy/overuse injury is conflicting. Our aim was to compare pressure pain thresholds (PPTs) in symptomatic and distant pain-free areas between patients with upper extremity tendinopathy/overuse injury and controls.

METHODS

Five databases were searched from inception to October 15, 2020. The authors selected case-control studies comparing PPTs between individuals with upper extremity tendinopathy/overuse injury and pain-free controls. Data were extracted for population, diagnosis, sample size, outcome, and type of algometer. Results were extracted by 3 reviewers. The methodological quality/risk of bias (Newcastle-Ottawa Quality Assessment Scale) and evidence level (Grading of Recommendations Assessment, Development and Evaluation approach) were assessed. Meta-analyses of symptomatic, segment-related, and distant pain-free areas were compared.

RESULTS

The search identified 807 publications with 19 studies (6 shoulder, 13 elbow) eligible for inclusion. The methodological quality ranged from fair (48%) to good (37%). Patients exhibited lower bilateral PPTs than controls at the symptomatic area (affected side: MD = -175.89 kPa [95% CI = -220.30 to -131.48 kPa]; nonaffected side: MD = -104.50 kPa [95% CI = -142.72 to -66.28 kPa]) and the segment-related area (affected side: MD = -150.63 kPa [95% CI = -212.05 to -89.21 kPa]; nonaffected side: MD = -170.34 kPa [95% CI = - 248.43 to -92.25]) than controls. No significant differences in PPTs over distant pain-free areas were observed.

CONCLUSION

Low to moderate quality evidence suggests bilateral hypersensitivity to pressure pain at the symptomatic and contralateral/mirror areas in patients with upper extremity tendinopathies/overuse injury. Moderate quality of evidence supports bilateral pressure pain sensitivity in the segment-related area (neck) in lateral epicondylalgia, but not in subacromial impingement syndrome. No evidence of widespread pressure pain hyperalgesia was reported.

IMPACT

Early identification of people with altered pain modulation could guide clinicians in treatment strategies. This review shows that there is a complex interplay between peripheral and central pain mechanisms in upper extremity tendinopathies/overuse injuries and that there likely are different subgroups of patients with upper extremity conditions.

Central Sensitization in Chronic Musculoskeletal Pain Disorders in Different Populations: A Cross-Sectional Study

OBJECTIVE

Chronic musculoskeletal pain disorders (CMPDs) are among the leading causes of disabilities across populations, resulting in high social and financial burden. This persistent pain condition may include the central sensitization (CS) phenomenon, which implies a wide range of symptoms and that may be taken into account in CMPD treatment. CS symptoms can be measured by the Central Sensitization Inventory (CSI). The aims of the study were to describe CS symptoms in patients suffering from several CMPDs and to analyze differences due to gender, age, and body mass index (BMI).

DESIGN

This cross-sectional study recruited a total of 395 Spanish participants suffering from several CMPDs.

SETTING

CS symptoms were measured with the Spanish Version of the CSI. The total score (0-100) and a cutoff score of 40 were recorded.

SUBJECTS

A total of 395 participants were included.

RESULTS

The mean CSI total score for the whole sample was 24.6 ± 12.0 points. CSI total score had subclinical values in the whole sample, whereas participants with scores >40 were found across different CMPDs, such as low back pain (37.8%) and neck pain (32.4%); 14.6% of females and 1.7% of males presented CSI scores >40. Patients showed significant differences in CSI cutoff point by gender (P = 0.010) and CSI total score by age (P = 0.014).

CONCLUSIONS

Given the high prevalence of clinically relevant CSI scores (>40) in people with a CMPD, especially low back pain and neck pain, we recommend that clinicians supplement their assessment with the CSI for improved decision-making during treatment.

Central sensitisation in chronic pain conditions: latest discoveries and their potential for precision medicine

Chronic pain is a leading cause of disability globally and associated with enormous health-care costs. The discrepancy between the extent of tissue damage and the magnitude of pain, disability, and associated symptoms represents a diagnostic challenge for rheumatology specialists. Central sensitisation, defined as an amplification of neural signalling within the CNS that elicits pain hypersensitivity, has been investigated as a reason for this discrepancy. Features of central sensitisation have been documented in various pain conditions common in rheumatology practice, including fibromyalgia, osteoarthritis, rheumatoid arthritis, Ehlers-Danlos syndrome, upper extremity tendinopathies, headache, and spinal pain. Within individual pain conditions, there is substantial variation among patients in terms of presence and magnitude of central sensitisation, stressing the importance of individual assessment. Central sensitisation predicts poor treatment outcomes in multiple patient populations. The available evidence supports various pharmacological and non-pharmacological strategies to reduce central sensitisation and to improve patient outcomes in several conditions commonly seen in rheumatology practice. These data open up new treatment perspectives, with the possibility for precision pain medicine treatment according to pain phenotyping as a logical next step. With this view, studies suggest the possibility of matching non-pharmacological approaches, or medications, or both to the central sensitisation pain phenotypes.

The Modulatory Effect of QST in Shoulder Pain: A Systematic Review and Meta-Analysis

BACKGROUND

The underlying mechanisms for shoulder pain (SP) are still widely unknown. Previous reviews report signs of altered pain processing in SP measured using quantitative sensory testing (QST). Evidence suggests that QST might hold predictive value for SP after intervention, yet it is not known whether QST profiles can be modulated in response to different treatments. Therefore, this systematic review and meta-analysis aimed to assess if QST-parameters can be modified by interventions for patients with SP.

METHODS

Three databases were searched to identify eligible studies. Eligible studies had a prospective design, with at least one QST variable as an outcome in conjunction with an intervention measured before and after intervention. Studies that involved SP caused by spinal or brain injury and studies looking at combined chronic neck/shoulder pain were excluded.

RESULTS

19 studies investigating SP were eligible for inclusion for this review. Pressure pain threshold (PPT) was the most frequently used QST-parameter investigating local and widespread hyperalgesia. A meta-analysis was performed with data from 10 studies with a total of 16 interventions. Results demonstrated an overall acute effect (<24 hours after intervention) of interventions in favour of local decreased pain sensitivity and of remote decreased pain sensitivity comparing PPTs before and after interventions.

CONCLUSIONS

This study demonstrates that interventions such as exercise and manual therapy can modulate PPTs acutely both locally and remotely in patients with shoulder pain. Further research investigating the acute and long-term modulatory ability of these interventions on other QST-parameters is needed in patients with shoulder pain.

Diagnostic ultrasound in patients with shoulder pain: An inter-examiner agreement and reliability study among Dutch physical therapists

STUDY DESIGN

A cross-sectional inter-examiner agreement and reliability study among physical therapists in primary care.

BACKGROUND

musculoskeletal ultrasound (MSU) is frequently used by physical therapists to improve specific diagnosis in patients with shoulder pain, especially for the diagnosis rotator cuff tendinopathy (RCT) including tears.

OBJECTIVES

To estimate the inter-examiner agreement and reliability in physical therapists using MSU for patients with shoulder pain.

METHODS

Physical therapists performed diagnostic MSU in 62 patients with shoulder pain. Both physical therapists were blinded to each other's results and patients were not informed about the test results. We calculated the overall inter-examiner agreement, specific positive and negative inter-examiner agreement, and inter-examiner reliability (Cohen's Kappa's).

RESULTS

Overall agreement for detecting RC ruptures ranged from 61.7% to 85.5% and from 43.9% to 91.4% for specific positive agreement. The specific negative agreement was lower with values ranging from 44.4% to 79.1% for RC ruptures. Overall agreement for other pathology than ruptures related to SAPS, ranged from 72.6% to 93.6% and from 77.3% to 96% for specific positive agreement. The specific negative agreement was lower with values ranging from 44.4% to 79.1% for RC ruptures and 52.5%-83.3% for other pathology than ruptures related to SAPS. Reliability values varied from substantial for any thickness ruptures to moderate for partial thickness ruptures and fair for full thickness tears. Moreover, reliability was fair for cuff tendinopathy. The reliability for AC arthritis and no pathology found was fair and moderate. There was substantial agreement for the calcifying tendinopathy.

CONCLUSIONS

Physical therapists using MSU agree on the diagnosis of cuff tendinopathy and on the presence of RCT in primary care, but agree less on the absence of pathology.

Development and validation of a shoulder-specific body-perception questionnaire in people with persistent shoulder pain

Background

There is evidence that people with persistent shoulder pain exhibit findings consistent with the presence of sensorimotor dysfunction. Sensorimotor impairments can manifest in a variety of ways, and further developing our understanding of sensorimotor dysfunction in shoulder pain may improve current models of care. The Fremantle Back Awareness Questionnaire (FreBAQ) has been developed to assess disturbed body perception specific to the back. The purpose of the present study was to develop a shoulder-specific self-perception questionnaire and evaluate the questionnaire in people with persistent shoulder pain.

Methods

The Fremantle Shoulder Awareness Questionnaire (FreSHAQ-J) was developed by modifying the FreBAQ. One hundred and twelve consecutive people with persistent shoulder pain completed the FreSHAQ-J. Thirty participants completed the FreSHAQ-J again two-weeks later to assess test-retest reliability. Rasch analysis was used to assess the psychometric properties of the FreSHAQ-J. Associations between FreSHAQ-J total score and clinical status was explored using correlational analysis.

Results

The FreSHAQ-J has acceptable category order, unidimensionality, no misfitting items, and excellent test-retest reliability. The FreSHAQ-J was moderately correlated with disability and pain catastrophization.

Conclusions

The FreSHAQ-J fits the Rasch measurement model well and is suitable for use with people with shoulder pain. Given the relationship between the FreSHAQ-J score and clinical status, change in body perception may be worth assessing when managing patients with shoulder pain.

A randomized clinical trial on the effect of a lidocaine patch on shoulder pain relief in laparoscopic cholecystectomy

The incidence of laparoscopy-related shoulder pain reaches 90% in women. We evaluated the effect of lidocaine patch 5% on the shoulder pain after laparoscopic cholecystectomy (LC) in female patients. Total 63 female patients were randomly allocated to patch group (n = 31) and control group (n = 32). Patch group received lidocaine patch 5% and dressing retention tape on both shoulder, and control group received only dressing retention tape. Abdominal and shoulder pains were evaluated with rating on numeric rating scale (0 = no pain and 10 = the worst pain) at baseline and at 30 min, 6 h, 24 h, and 48 h after surgery. There were no significant differences in patient characteristics and operation details. The overall incidence of shoulder pain was significantly lower in patch group than in control group (42% vs. 78%, P = 0.005). The severity of shoulder pain also was significantly reduced in patch group compared to control group at 24 h and 48 h after surgery (P = 0.01 and P = 0.015, respectively). Complications related to lidocaine patch were not found except nausea. Lidocaine patch 5% reduced the incidence and severity of postoperative shoulder pain in female patients undergoing LC without complications.

Transcultural reliability and validity of an Italian language version of the Constant–Murley Score

Purpose:

The present study was designed to carry out an Italian translation of the Constant–Murley Score (CMS-IT) and, subsequently, evaluate its reliability and validity.

Methods:

This study included adults diagnosed with any type of clinical shoulder dysfunction who could read and respond to the questionnaires. Those individuals who underwent surgeries of any kind on the affected shoulder during the previous 12 months and individuals with shoulder instabilities were excluded. All of the participants were evaluated by two operators, and the CMS-IT, Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, and visual analog scale (VAS) were administered. The internal consistency was evaluated using Cronbach’s α, whereas the intra-rater and inter-rater reliabilities were evaluated using the intraclass correlation coefficient (ICC). The validity of the construction was evaluated using Pearson’s correlation coefficient between the scores of the administered scales.

Results:

A population of 72 individuals participated in this study. The internal consistency of the CMS-IT showed a value of 0.81. The ICC values showed that inter- and intra-rater reliability were 0.994 and 0.963, respectively. CMS-IT is inversely correlated with the VAS (−0.55) and DASH (−0.47) scales.

Conclusions:

This study revealed that the CMS-IT contained good internal consistency and good reliability. The results suggested that the CMS-IT questionnaire is a reliable and valid tool for assessing the shoulder dysfunctions of the Italian population, and it deserves broad applications in both clinical practice and research contexts. The scale can also be used as an alternative to the current “gold standard” VAS and DASH.

Biopsychosocial Aspects in Individuals with Acute and Chronic Rotator Cuff Related Shoulder Pain: Classification Based on a Decision Tree Analysis

Biopsychosocial aspects seem to influence the clinical condition of rotator cuff related shoulder pain (RCRSP). However, traditional bivariate and linear analyses may not be sufficiently robust to capture the complex relationships among these aspects. This study determined which biopsychosocial aspects would better classify individuals with acute and chronic RCRSP and described how these aspects interact to create biopsychosocial phenotypes in individuals with acute and chronic RCRSP. Individuals with acute (<six months of pain, n = 15) and chronic (≥six months of pain, n = 38) RCRSP were included. Sociodemographic data, biological data related to general clinical health status, to shoulder clinical condition and to sensory function, and psychosocial data were collected. Outcomes were compared between groups and a decision tree was used to classify the individuals with acute and chronic RCRSP into different phenotypes hierarchically organized in nodes. Only conditioned pain modulation was different between the groups. However, the tree combined six biopsychosocial aspects to identify seven distinct phenotypes in individuals with RCRSP: three phenotypes of individuals with acute, and four with chronic RCRSP. While the majority of the individuals with chronic RCRSP have no other previous painful complaint besides the shoulder pain and low efficiency of endogenous pain modulation with no signs of biomechanical related pain, individuals with acute RCRSP are more likely to have preserved endogenous pain modulation and unilateral pain with signs of kinesiophobia.

Evaluation of the Central Sensitization Inventory Score in elderly adults with musculoskeletal examination

OBJECTIVES

The present study aimed to conduct an epidemiological survey of Central Sensitization Inventory (CSI) scores in an older adult population and to investigate the association between the CSI scores, age, sex, pain intensity, site of pain, and health-related quality of life (QOL).

METHODS

Participants were 373 Japanese adults aged ≥ 50 years who underwent a health checkup in 2018. We collected demographic data and clinical characteristics along with the CSI scores, QOL questionnaire, site of pain (neck, lower back, upper limb, and lower limb) and pain severity. We performed an epidemiological survey of the CSI scores and investigated the gender difference in CSI scores and the relationship between the CSI scores, site of pain, and QOL.

RESULTS

The prevalence of low back pain was the highest (67.6%). The average CSI score was 14.2 points; 8% of volunteers had a high (> 30) CSI score. The CSI scores among women were significantly higher than those among men (p = .016). The CSI scores had a significantly moderate correlation with the numerical rating scale and QOL scores (all p < .001). Volunteers with neck pain showed the highest CSI scores (average 22.4 points).

CONCLUSIONS

The CSI total score showed sex differences and had a significant correlation with pain severity and QOL.

STUDY DESIGN

Cross-sectional study.

Psychosocial factors, disability and quality of life in chronic shoulder pain patients with central sensitization

Chronic shoulder pain is a complex and multidimensional phenomenon with multiple causative factors involved in its perpetuation. Alteration of central nervous system processing along with the central sensitization is a predominant feature in chronic pain. Reduction in physical function has an impact on the psychological well-being of an individual. The aim of the study was to compare pain, kinesiophobia, catastrophizing, disability and quality of life in chronic shoulder pain patients with and without central sensitization. Eighty chronic unilateral shoulder pain patients in the age group of 40 to 60 years were recruited. Of them, 38 were chronic shoulder pain with central sensitization and 42 without central sensitization, classified on the basis of central sensitization inventory. Pain catastrophizing was measured using the pain catastrophizing scale, kinesiophobia using Tampa scale of kinesiophobia, disability using Shoulder pain and disability index and quality of life using 36-Item Short Form Health Survey questionnaire was evaluated in both the groups. Increased pain catastrophizing (p=0.000), kinesiophobia (p=0.000) and disability (p=0.000) was observed in centrally sensitized chronic shoulder pain patients. Also, physical component summary (p=0.000) and mental component summary (p=0.000) of SF-36 quality of life were reduced in chronic shoulder pain with central sensitization as compared to without central sensitization. Hence, these components should be included during assessment which will provide a holistic and multimodal approach towards the understanding, planning and management of chronic shoulder pain patients.

Conditioned pain modulation in elite athletes: a systematic review and meta-analysis

Background and aims Elite athletes reportedly have superior pain tolerances, but it is unclear if results extend to conditioned pain modulation (CPM). The aim of our study was to synthesize existing literature in order to determine whether CPM is increased in elite athletes compared to healthy controls. Methods A systematic review and random-effects meta-analysis was conducted. Cochrane Central Register of Controlled Trials, SPORTDiscus, PsycINFO, CINAHL, Web of Science, and PubMed were searched for English-language studies that examined CPM in adult elite athlete populations. Results Seven studies were identified; all were of poor to fair methodological quality. There was no overall difference in CPM between elite athletes and controls (Hedges g = 0.37, CI95 -0.03-0.76; p = 0.07). There was heterogeneity between studies, including one that reported significantly less CPM in elite athletes compared to controls. An exploratory meta-regression indicated that a greater number of hours trained per week was associated with higher CPM. Conclusions The overall number and quality of studies was low. Despite nominally favoring higher CPM in elite athletes, aggregate results indicate no significant difference compared to healthy controls. A possible factor explaining the high degree of variability between studies is the number of hours elite athletes spent training. Implications Based on available evidence, athletes do not have remarkable endogenous pain modulation compared to controls. High quality experimental studies are needed to address the effect of hours trained per week on CPM in athletes.

Relationships Between Psychological, Sleep, and Physical Activity Measures and Somatosensory Function in People With Peripheral Joint Pain: A Systematic Review and Meta-Analysis

OBJECTIVE

Alteration in somatosensory function has been linked to pain experience in individuals with joint pain. In this systematic review we aimed to establish the level of evidence of associations between psychological, social, physical activity, and sleep measures and somatosensory function that were assessed via quantitative sensory testing (QST) among individuals with joint pain.

METHODS

A comprehensive literature search was conducted in 6 electronic databases from their inception to July 2019. Two reviewers independently assessed the methodological quality using a modified Quality in Prognostic Studies (QUIPS) tool and supplemented with recommendations from the Critical Appraisal and Data Extraction for Systematic Review of Prediction Modelling Studies (CHARMS) checklist and the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. The level of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) system. Data were pooled to evaluate the strength of the relationships of interest.

RESULTS

Seventeen studies related to joint pain were included. Pain catastrophizing, depression, anxiety, and physical activity level have been shown to have a significant (small to fair) association with several QST measures. Pressure pain threshold (PPT) is the only measure that was found to be consistently correlated with all the domains. The overall quality of evidence for all factors ranged from very low to moderate. Subgroup analysis revealed a stronger association for depression and pain catastrophizing and PPT and temporal pain summation in individuals with shoulder pain.

CONCLUSION

Psychological factors and physical activity levels are associated with somatosensory function in people with joint pain. These factors need to be adjusted when establishing predictive relationships between somatosensory function and pain outcomes in individuals with joint pain.

The challenge of the sporting shoulder: From injury prevention through sport-specific rehabilitation toward return to play

Shoulder injuries and sports-related shoulder pain are substantial burdens for athletes performing a shoulder loading sport. The burden of shoulder problems in the athletic population highlights the need for prevention strategies, effective rehabilitation programs, and a individually based return-to-play (RTP) decision. The purpose of this clinical commentary is to discuss each of these 3 challenges in the sporting shoulder, to assist the professional in: (1) preventing injury; (2) providing evidence-based practice rehabilitation and; (3) to guide the athlete toward RTP. The challenges for injury prevention may be found in the search for (the interaction between) relevant risk factors, develop valid screening tests, and implement feasible injury prevention programmes with maximal adherence from the athletes. Combined analytical and functional testing seems mandatory screening an athlete's performance. Many questions arise when rehabilitating the overhead athlete, from exercise selection, over the value of stretching, toward kinetic chain implementation and progression to high performance training. Evidence-based practice should be driven by the available research, clinical expertise and the patient's expectations. Deciding when to return to sport after a shoulder injury is complex and multifactorial. The main concern in the RTP decision is to minimize the risk of re-injury. In the absence of a "gold standard", clinicians may rely on general guidelines, based on expert opinion, regarding cutoff values for normal range of motion, strength and function, with attention to risk tolerance and load management.

Pressure pain sensitivity in patients with traumatic first-time and recurrent anterior shoulder dislocation: a cross-sectional analysis

Background and aims Traumatic anterior shoulder dislocation (ASD) is frequent in active populations and associated with a 39% higher risk of recurrent dislocation, which may cause persistent shoulder problems, pain, and impaired shoulder-related quality of life. While local and distant pressure pain sensitivity has been demonstrated in other shoulder conditions, little is known about the link between pressure pain sensitivity and ASD. The interesting aspect is whether recurrent dislocation - resulting in symptoms of longer duration - is associated with more pronounced pressure pain sensitivity, or if presence of pressure pain sensitivity may be part of the reasons why patients develop recurrent dislocation. Therefore, this study aimed at evaluating whether patients with recurrent ASD display greater pressure pain sensitivity and more painful body sites than patients with first-time ASD. Methods This was a cross-sectional analysis of baseline data from a randomized controlled trial including 34 patients with first-time ASD [82% male, mean (SD) age 26 (7) years] and 22 patients with recurrent ASD [96% male, mean (SD) age 25 (5) years]. Patients were assessed as follows: (1) assessment of local and distant pressure pain sensitivity evaluated by pressure pain thresholds (PPTs) using a handheld algometer on mm. trapezius superior, levator scapula, pectorales major, deltoideus, and tibialis anterior, (2) pain intensity at rest during the previous 24 h, (3) number of ASD, and (4) number of painful body sites on a region-divided body chart. Results The PPTs were not significantly different between first-time and recurrent ASD [mean (SD) kPa for m. trapezius superior 264 (110) vs. 261 (88), m. levator scapula 301 (157) vs. 325 (163), m. pectorales major 234 (163) vs. 269 (130), m. deltoideus 290 (166) vs. 352 (173), m. tibialis anterior 420 (202) vs. 449 (184)], two-way ANCOVA, adjusted for sex and age, F (4,263) = 0.29, p = 0.88. For both groups, the PPTs were lower at the shoulder sites than at m. tibialis anterior (difference 117-184 kPa, 95% CI range 33-267). Females had lower PPTs than males (difference 124 kPa, 95% CI 64-183). The number (SD) of painful body sites were 2.2 (1.9) for first-time ASD and 2.6 (5.4) for recurrent ASD, with no between-group differences, one-way ANCOVA, adjusted for sex and age, F (1, 52) = 0.24, p = 0.63. There was a strong correlation between PPTs at the shoulder and lower leg, r = 0.84, p < 0.01. Conclusions This study demonstrated no differences in local and distant pressure pain sensitivity or number of painful body sites between patients with first-time and recurrent ASD. Females had lower PPTs than males, and a strong correlation was found between PPTs at the shoulder and lower leg. Implications Patients with first-time and recurrent ASD seem to have similar pressure pain sensitivity, but lower PPTs compared to existing normative data, suggesting that it is relevant to evaluate the status of the pain system in these patients to prevent triggering or worsening of their symptoms. However, it remains unanswered how these changes affect the patients' ability to undergo rehabilitation, symptom response and long-term shoulder function.

Cross-cultural adaptation and validity of the Spanish fear-avoidance components scale and clinical implications in primary care

BACKGROUND

Pain-related fear-avoidance (FA) is a common problem affecting many patients with painful medical conditions. As there is great interest in the clinical importance of the relationship between FA and disability, several questionnaires have been developed to measure FA. The Fear-Avoidance Components Scale (FACS) is a recently developed patient-reported instrument that addresses critical issues not previously considered in previous FA-related questionnaires. The original English version of the FACS demonstrated good reliability, internal consistency, and construct, criterion, and predictive validity. Two factors were determined: General Fear Avoidance and Types of Activities That are Avoided. The aim of this study was to to translate the FACS into European-style Spanish (FACS-Sp), and validate its psychometric properties.

METHODS

This two-stage psychometric study included 330 subjects with various chronic musculoskeletal pain disorders. An initial translation and cross-cultural adaptation of the FACS, from English to Spanish, was performed. Then, critical psychometric properties were analysed, including internal consistency by Cronbach's α coefficients, structural validity from the Maximum Likelihood Extraction (MLE), and convergent validity by Pearson correlation with the Central Sensitization Inventory (CSI).

RESULTS

This study reports for the first time the psychometric properties of the Spanish version of the FACS. Total scores ranged from 0 to 88 points, with a mean of 30.49 (±17.18). The FACS-Sp showed a high internal consistency for factor 1 (α = 0.902) and factor 2 (α = 0.88). Factor structure was two-dimensional and supported structural validity, accounting for 48.75% of the total variance. Convergent validity analysis found a significant Pearson correlation r = 0.414.

CONCLUSION

This study reports for the first time the psychometric properties of the Spanish version of the FACS-Sp. Psychometric properties supported the validation of FACS-Sp and ensured the conceptual equivalence with the original English version. In primary care and chronic pain rehabilitation, FA assessment is crucial for clinical decision-making and treatment guidance. The FACS-Sp offers a new measure of FA in Spanish speaking populations. Future research on the FACS-Sp should evaluate test-retest reliability, treatment responsiveness and psychometric comparisons with other translated versions.

Cross-cultural adaptation and validity of the Spanish fear-avoidance components scale and clinical implications in primary care

BACKGROUND

Pain-related fear-avoidance (FA) is a common problem affecting many patients with painful medical conditions. As there is great interest in the clinical importance of the relationship between FA and disability, several questionnaires have been developed to measure FA. The Fear-Avoidance Components Scale (FACS) is a recently developed patient-reported instrument that addresses critical issues not previously considered in previous FA-related questionnaires. The original English version of the FACS demonstrated good reliability, internal consistency, and construct, criterion, and predictive validity. Two factors were determined: General Fear Avoidance and Types of Activities That are Avoided. The aim of this study was to to translate the FACS into European-style Spanish (FACS-Sp), and validate its psychometric properties.

METHODS

This two-stage psychometric study included 330 subjects with various chronic musculoskeletal pain disorders. An initial translation and cross-cultural adaptation of the FACS, from English to Spanish, was performed. Then, critical psychometric properties were analysed, including internal consistency by Cronbach's α coefficients, structural validity from the Maximum Likelihood Extraction (MLE), and convergent validity by Pearson correlation with the Central Sensitization Inventory (CSI).

RESULTS

This study reports for the first time the psychometric properties of the Spanish version of the FACS. Total scores ranged from 0 to 88 points, with a mean of 30.49 (±17.18). The FACS-Sp showed a high internal consistency for factor 1 (α = 0.902) and factor 2 (α = 0.88). Factor structure was two-dimensional and supported structural validity, accounting for 48.75% of the total variance. Convergent validity analysis found a significant Pearson correlation r = 0.414.

CONCLUSION

This study reports for the first time the psychometric properties of the Spanish version of the FACS-Sp. Psychometric properties supported the validation of FACS-Sp and ensured the conceptual equivalence with the original English version. In primary care and chronic pain rehabilitation, FA assessment is crucial for clinical decision-making and treatment guidance. The FACS-Sp offers a new measure of FA in Spanish speaking populations. Future research on the FACS-Sp should evaluate test-retest reliability, treatment responsiveness and psychometric comparisons with other translated versions.

Psychological factors are associated with local and generalized pressure pain hypersensitivity, pain intensity, and function in people with chronic shoulder pain: A cross-sectional study

OBJECTIVES

To explore the association between psychological factors and shoulder pain intensity, function, as well as local and generalized pressure pain hypersensitivity.

DESIGN

a cross-sectional study.

METHODS

90 participants with chronic shoulder pain were included. Pressure pain thresholds determined the presence of pain hypersensitivity. Pain intensity, function, pain self-efficacy, emotional distress, and pain catastrophizing were also assessed. Analyses were adjusted for gender and age.

RESULTS

The diagnosis of depression (yes/no answer) was associated with both greater local (standardized β = -0.19[95%CI -0.37 to -0.00]) and generalized (standardized β = -0.20[95%CI -0.39 to -0.01]) pressure pain hypersensitivity. Greater pain self-efficacy was associated with lower local pressure pain hypersensitivity (standardized β = 0.19[95%CI 0.04 to 0.38]). The standardized beta coefficient for the diagnosis of depression indicated that this variable showed the strongest association with pressure pain hypersensitivity. Additionally, greater pain self-efficacy was associated with lower pain intensity (standardized β = -0.34[95%CI -0.51 to -0.17]) and better function (standardized β = -0.47[95%CI -0.63 to -0.30]). Greater pain catastrophizing was associated with more pain intensity (standardized β = 0.35[95%CI 0.18 to 0.52]) and worse function (standardized β = 0.26[95%CI 0.10 to 0.43]). The standardized beta coefficients for pain catastrophizing and pain self-efficacy indicated that both variables showed the strongest association with shoulder pain intensity and function, respectively CONCLUSION: Psychological factors were associated with local and generalized pressure pain hypersensitivity, pain intensity, and function in people with chronic shoulder pain.