Influence of shoulder pain on muscle function: implications for the assessment and therapy of shoulder disorders

Shoulder pain is often a challenging clinical phenomenon because of the potential mismatch between pathology and the perception of pain. Current evidence clearly emphasizes an incomplete understanding of the nature of shoulder pain. Indeed, the effective diagnosis and treatment of shoulder pain should not only rely upon a detailed knowledge of the peripheral pathologies that may be present in the shoulder, but also on current knowledge of pain neurophysiology. To assess and treat shoulder pain, a comprehensive understanding of the way in which pain is processed is essential. This review reflects modern pain neurophysiology to the shoulder and aims to answer the following questions: why does my shoulder hurt? What is the impact of shoulder pain on muscle function? What are the implications for the clinical examination of the shoulder? And finally, what are the clinical implications for therapy? Despite the increasing amount of research in this area, an in-depth understanding of the bidirectional nociception-motor interaction is still far from being achieved. Many questions remain, especially related to the treatment of nociception-motor interactions

A multivariable prediction model for the chronification of non-traumatic shoulder pain : a systematic review

Background: Shoulder pain is the third most common musculoskeletal complaint and many patients have an unfavorable outcome with long-term disability. Only 50% of all new episodes of shoulder pain show complete recovery within 6 months. Little is known about factors that contribute to chronicity of shoulder pain, although such information is needed for the management of patients with acute and sub-acute shoulder pain. Objective: To systematically review the literature for prognostic factors which are potential predictors for either recovery or chronification in patients with acute and sub-acute non-traumatic shoulder pain. Study Design: Systematic review. Setting: This systematic review examined all studies involving the prognosis of shoulder pain patients. Methods: This systematic review was reported following the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Two reviewers independently scored the methodological quality of the selected studies. Due to heterogeneity of studies, a best-evidence synthesis of the available prognostic factors was provided. Results: Nine studies met our inclusion criteria and were included in this systematic review. There is strong evidence that high scores on the Shoulder Pain and Disability Index (SPADI), high scores on shoulder pain severity, and a long duration of complaints are factors that contribute to the chronification of shoulder pain. Moderate evidence was found supportive for other prognostic factors that enhance chronification, like being male, being over 55 years of age, having poor general health, having a gradual onset of complaints, a large amount of sick leave, the perception of high job demand, the perception of low social support, and the amount of visits to a health care professional. Also moderate evidence exists regarding factors that contributed to a reduced possibility of chronification: an active treatment policy and not taking medication on regular basis. Limitations: The large variability in definitions of shoulder pain, and patient selection bias. In addition, there is a paucity of strong longitudinal prospective studies. Conclusion: This systematic review found evidence that high scores on the SPADI questionnaire, more shoulder pain, and a longer duration of complaints are associated with chronification of shoulder pain. In order to reduce chronification, clinicians can use the International Classification of Functioning based model presented here that could aid their decision-making

Efficacy of combined strategies of physical activity, diet and sleep disorders as treatment in patients with chronic shoulder pain. A systematic review

Introduction: The objective of this systematic review was to analyze the existing scientific evidence on the influence of dietary strategies, exercise, and sleep disorders on the symptomatology of patients with chronic shoulder pain, as well as to assess the methodological quality of the literature collected. Methods: The selection criteria were as follows: we included randomized controlled clinical trials written in English that investigated the effects of such interventions in patients with chronic shoulder pain and excluded studies where pre-operative rehabilitation or rehabilitation combined with corticosteroid injections was performed. We searched six databases Pubmed, Cochrane Library, Web of Science, CINAHL, Sportdiscus and Scopus, using the keywords “shoulder pain,” “fasting,” “physical therapy modalities,” “rehabilitation,” “exercise,” “circadian clocks,” and “chronic pain” to select randomized controlled clinical trials conducted in humans and written in English. The last search was conducted on 24/01/2023. (PROSPERO:CRD42023379925). Results: We used the tool proposed by the Cochrane Handbook to assess the risk of bias in the included studies of the 17 studies included, nine had a high risk of bias, two studies had an unclear risk of bias, and the remaining six studies had a low risk of bias. A total of 17 articles were selected, including 10 studies that showed a positive influences of exercise on chronic shoulder pain and five studies that showed a negative influence of sleep disorders on this patient profile. The remaining two articles analyzed the influence of nutritional strategies and metabolic problems in patients with chronic shoulder pain. The total sample size of the 17 included articles amounted to 9,991 individuals. Discussion: Studies confirm that exercise generates a hypoalgesic effect that improves chronic shoulder pain, functionality, and quality of life. Although dietary strategies and sleep disorders are known to influence chronic shoulder pain, there is a lack of studies that conduct interventions on these problems to assess how chronic shoulder pain varies.University Chair in Clinical Psychoneuroimmunology (University of Granada and PNI Europe

Does acetaminophen activate endogenous pain inhibition in chronic fatigue syndrome/fibromyalgia and rheumatoid arthritis? : a double-blind randomized controlled cross-over trial

Background: Although enhanced temporal summation (TS) and conditioned pain modulation (CPM), as characteristic for central sensitization, has been proved to be impaired in different chronic pain populations, the exact nature is still unknown. Objectives: We examined differences in TS and CPM in 2 chronic pain populations, patients with both chronic fatigue syndrome (CFS) and comorbid fibromyalgia (FM) and patients with rheumatoid arthritis (RA), and in sedentary, healthy controls, and evaluated whether activation of serotonergic descending pathways by acetaminophen improves central pain processing. Study Design: Double-blind randomized controlled trial with cross-over design. Methods: Fifty-three women (19 CFS/FM patients, 16 RA patients, and 18 healthy women) were randomly allocated to the experimental group (1 g acetaminophen) or the placebo group (1 g dextrose). Participants underwent an assessment of endogenous pain inhibition, consisting of an evaluation of temporal summation with and without conditioned pain modulation (CPM). Seven days later groups were crossed-over. Patients and assessors were blinded for the allocation. Results: After intake of acetaminophen, pain thresholds increased slightly in CFS/FM patients, and decreased in the RA and the control group. Temporal summation was reduced in the 3 groups and CPM at the shoulder was better overall, however only statistically significant for the RA group. Healthy controls showed improved CPM for both finger and shoulder after acetaminophen, although not significant. Limitations: The influence of acetaminophen on pain processing is inconsistent, especially in the patient groups examined. Conclusion: This is the first study comparing the influence of acetaminophen on central pain processing in healthy controls and patients with CFS/FM and RA. It seems that CFS/ FM patients present more central pain processing abnormalities than RA patients, and that acetaminophen may have a limited positive effect on central pain inhibition, but other contributors have to be identified and evaluated

Influence of psychological factors on the prognosis of chronic shoulder pain : protocol for a prospective cohort study

Introduction: Shoulder pain is a highly prevalent condition. Psychological factors could play an essential role in the prognosis of chronic shoulder pain (CSP). The aims of the study will be to analyse the level of association between psychological factors and pain-disability at baseline and prospectively to assess their prognostic role; to evaluate the association of pain catastrophising and kinesiophobia at baseline and prospectively in the relationship between pain intensity and disability, or between self-efficacy and disability in patients with CSP; to explore the association of self-efficacy at baseline and prospectively in the relationship between pain intensity and disability, in comparison with kinesiophobia and pain catastrophising. Methods and analysis: The study is a longitudinal, prospective cohort study with a 12-month follow-up. It will be conducted in 4 primary-care centres and one hospital of the province of Malaga, Spain. 307 participants aged between 18 and 70 years suffering from CSP (3 months or more) will be included. Primary outcomes will include pain, disability and self-efficacy, whereas kinesiophobia, pain-related fear, pain catastrophising, anxiety, depression, patient expectations of recovery, age, gender, duration/intensity of symptoms, educational level and other factors will be predictive measures. Follow-up: baseline, 3, 6 and 12 months. Ethics and dissemination: The local ethics committee (The Costa del Sol Ethics Committee, Malaga, 28042016) has approved this protocol. Dissemination will occur through presentations at National and International conferences and publications in international peer-reviewed journals

The result of acute induced psychosocial stress on pain sensitivity and modulation in healthy people

Background: Pain can be influenced by several factors, including stress. Stress can have various reactions on pain. These reactions are influenced by several internal factors such as gender, age, and experience with stress or pain. Objectives: To determine the effect of acute stress on mechanical hyperalgesia (with pressure pain thresholds [PPT]), endogenous pain facilitation (measured by temporal summation [TS]), and inhibition (measured by conditioned pain modulation [CPM]) in healthy people and to determine which factors are responsible for this stress result. Study Design: Pre-posttest design. Setting: Healthy volunteers from Belgium. Methods: One hundred and one healthy pain-free patients underwent a modified Trier Social Stress Test. Prior and following the stress manipulation, PPT, TS, and CPM efficacy were determined in the mm. trapezius and quadriceps and overall. Furthermore, possible explanatory factors, such as fear of pain, pain catastrophizing, pain hypervigilance, and daily activity levels, were assessed using questionnaires. Results: We found a significant stress result on widespread pain sensitivity, with an increase of PPT (P 0.05), and a decrease in CPM efficacy (P < 0.001). Factors associated with the stress result were age, previous surgery, attentional focus on the conditioning stimulus during CPM, fear of pain, and daily activity levels. Limitations: The efficacy of the stress manipulation was not examined, and the lack of a control group prevented to examine a real stress-effect. Furthermore, no physiologic parameters were measured as possibly influencing internal factors for the stress-result. Conclusions: The increase in PPT was not a clinically significant change, whereas the decrease in CPM was meaningful. None of the factors predicted the stress result in all experimental pain measurements, and the predictions that were observed only explained a small proportion of the observed effects

Differences in scapular upward rotation, pectoralis minor and levator scapulae muscle length between the symptomatic, the contralateral asymptomatic shoulder and control subjects: a cross-sectional study in a Spanish primary care setting

Objective To determine the potential differences in both scapular positioning and scapular movement between the symptomatic and asymptomatic contralateral shoulder, in patients with unilateral subacromial pain syndrome (SAPS), and when compared with participants free of shoulder pain. Setting Three different primary care centres. Participants A sample of 73 patients with SAPS in their dominant arm was recruited, with a final sample size of 54 participants. Primary outcome measures The scapular upward rotation (SUR), the pectoralis minor and the levator scapulae muscles length tests were carried out. Results When symptomatic shoulders and controls were compared, an increased SUR at all positions (45°, 90° and 135°) was obtained in symptomatic shoulders (2/3,98/8,96°, respectively). These differences in SUR surpassed the minimal detectable change (MDC95) (0,91/1,55/2,83° at 45/90/135° of shoulder elevation). No differences were found in SUR between symptomatic and contralateral shoulders. No differences were found in either pectoralis minor or levator scapulae muscle length in all groups. Conclusions SUR was greater in patients with chronic SAPS compared with controls at different angles of shoulder elevation

An update of systematic reviews examining the effectiveness of conservative physical therapy interventions for subacromial shoulder pain

OBJECTIVE: To update a systematic review published in 2013 that focused on evaluating the effectiveness of interventions within the scope of physical therapy, including exercise, manual therapy, electrotherapy, and combined or multimodal approaches to managing shoulder pain. U DESIGN: Umbrella review. U LITERATURE SEARCH: An electronic search of PubMed, Web of Science, and CINAHL was undertaken. Methodological quality was assessed using the AMSTAR (A MeaSurement Tool to Assess systematic Reviews) checklist for systematic reviews. • STUDY SELECTION CRITERIA: Nonsurgical treatments for subacromial shoulder pain. • DATA SYNTHESIS: Sixteen systematic reviews were retrieved. Results were summarized qualitatively. • RESULTS: A strong recommendation can be made for exercise therapy as the first-line treatment to improve pain, mobility, and function in patients with subacromial shoulder pain. Manual therapy may be integrated, with a strong recommendation, as additional therapy. There was moderate evidence of no effect for other commonly prescribed interventions, such as laser therapy, extracorporeal shockwave therapy, pulsed electromagnetic energy, and ultrasound. • CONCLUSION: There is a growing body of evidence to support exercise therapy as an intervention for subacromial shoulder pain. Ongoing research is required to provide guidance on exercise type, dose, duration, and expected outcomes. A strong recommendation may be made regarding the inclusion of manual therapy in the initial treatment phase

Efficacy of combined strategies of physical activity, diet and sleep disorders as treatment in patients with chronic shoulder pain. A systematic review

Introduction: The objective of this systematic review was to analyze the existing scientific evidence on the influence of dietary strategies, exercise, and sleep disorders on the symptomatology of patients with chronic shoulder pain, as well as to assess the methodological quality of the literature collected.Methods: The selection criteria were as follows: we included randomized controlled clinical trials written in English that investigated the effects of such interventions in patients with chronic shoulder pain and excluded studies where pre-operative rehabilitation or rehabilitation combined with corticosteroid injections was performed. We searched six databases Pubmed, Cochrane Library, Web of Science, CINAHL, Sportdiscus and Scopus, using the keywords “shoulder pain,” “fasting,” “physical therapy modalities,” “rehabilitation,” “exercise,” “circadian clocks,” and “chronic pain” to select randomized controlled clinical trials conducted in humans and written in English. The last search was conducted on 24/01/2023. (PROSPERO:CRD42023379925).Results: We used the tool proposed by the Cochrane Handbook to assess the risk of bias in the included studies of the 17 studies included, nine had a high risk of bias, two studies had an unclear risk of bias, and the remaining six studies had a low risk of bias. A total of 17 articles were selected, including 10 studies that showed a positive influences of exercise on chronic shoulder pain and five studies that showed a negative influence of sleep disorders on this patient profile. The remaining two articles analyzed the influence of nutritional strategies and metabolic problems in patients with chronic shoulder pain. The total sample size of the 17 included articles amounted to 9,991 individuals.Discussion: Studies confirm that exercise generates a hypoalgesic effect that improves chronic shoulder pain, functionality, and quality of life. Although dietary strategies and sleep disorders are known to influence chronic shoulder pain, there is a lack of studies that conduct interventions on these problems to assess how chronic shoulder pain varies