Objective: The aims of this study were to examine: (i) baseline pressure pain thresholds in patients with chronic fatigue syndrome and those with chronic low back pain compared with healthy subjects; (ii) the change in mean pain threshold in response to exercise; and (iii) associations with exerciseinduced increase in nitric oxide. Participants: Twenty-six patients with chronic fatigue syndrome suffering of chronic pain, 21 patients with chronic low back pain and 31 healthy subjects. Methods: Participants underwent a submaximal aerobic exercise protocol on a bicycle ergometer, preceded and followed by venous blood sampling (nitric oxide) and algometry (hand, arm, calf, low back). Results: Patients with chronic fatigue syndrome presented overall lower pain thresholds compared with healthy subjects and patients with chronic low back pain (p < 0.05). No significant differences were found between healthy subjects and patients with chronic low back pain. After submaximal aerobic exercise, mean pain thresholds decreased in patients with chronic fatigue syndrome, and increased in the others (p < 0.01). At baseline, nitric oxide levels were significantly higher in the chronic low back pain group. After controlling for body mass index, no significant differences were seen between the groups at baseline or in response to exercise. Nitric oxide was not related to pain thresholds in either group. Conclusion: The results suggest hyperalgesia and abnormal central pain processing during submaximal aerobic exercise in chronic fatigue syndrome, but not in chronic low back pain. Nitric oxide appeared to be unrelated to pain processing.

It tempting to speculate that ongoing nociception is associated with cortical and subcortical reorganization and may play an important role in the process of the chronification of LBP. Future prospective research should explore to what extent these changes are reversible and if this reversibility is associated with improved functioning of patients.

This section focuses on combining pharmacotherapy with multimodal rehabilitation for balancing the deleterious and therapeutic effects of BNDF treatment in chronic pain patients, as well as accounting for the complex and biopsychosocial nature of chronic pain.

OBJECTIVE. The objective of this study was to evaluate the effectiveness of an activity pacing self-management (APSM) intervention in improving performance of daily life activities in women with chronic fatigue syndrome (CFS). METHOD. A total of 33 women with CFS (age 41.1 ± 11.2 yr) were randomly allocated to APSM (experimental group; n = 16) or relaxation (control group; n = 17). Main outcome measures included the Canadian Occupational Performance Measure (COPM; primary) and Checklist Individual Strength (CIS). RESULTS. COPM scores changed significantly over time in both groups (p = .03). The change in Satisfaction scores showed a significant difference in favor only of APSM (effect size = 0.74 [0.11, 1.4]). CIS scores decreased significantly in the experimental group only (p &lt; .01). CONCLUSION. APSM was found to be feasible and effective in optimizing participation in desired daily life activities in women with CFS. Replication in a larger sample with long-term follow-up is required.

The objective of this prospective study is to investigate possible scapular related risk factors for developing shoulder pain. Therefore, a 2-year follow-up study in a general community sports centre setting was conducted. A sample of convenience of 113 recreational overhead athletes (59 women and 54 men) with a mean age of 34 (17-64; SD 12) years were recruited. At baseline, visual observation for scapular dyskinesis, measured scapular protraction, upward scapular rotation and dynamic scapular control were evaluated. 22% (n=25) of all athletes developed shoulder pain during the 24 months following baseline assessment. The Mean Shoulder Disability Questionnaire (SDQ) score for the painful shoulders was 34.8 (6.3-62.5; SD 17.4). None of the scapular characteristics predicted the development of shoulder pain. However, the athletes that developed shoulder pain demonstrated significantly less upward scapular rotation at 45° (p=0.010) and 90° (p=0.016) of shoulder abduction in the frontal plane at baseline in comparison to the athletes that remained pain-free. In conclusion, although these scapular characteristics are not of predictive value for the development of shoulder pain, this study increases our understanding of the importance of a scapular upward rotation assessment among recreational overhead athletes.

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 nontraumatic 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. Key words: Shoulder pain, prognostic factors, systematic review, prognosis, assessment

Objective To assess the effect of different dosages of pain neuroscience education (PNE) programs on central nociceptive processing in patients with fibromyalgia. Second, to compare the effects of different dosages of PNE programs on numerical pain rating scale (NPRS), disability, and psychological variables. Design Single-blind randomized controlled trial. Setting Three fibromyalgia centers in Spain (Valencia, Alcorcón, Alcalá de Henares). Subjects Seventy-seven patients with fibromyalgia. Methods Participants were randomized to four groups of PNE: 1) high-dose PNE (N = 20), 2) low–concentrated dose PNE (N = 20), 3) diluted low-dose PNE (N = 20), and (4) control treatment (N = 17), conducted in two 30–50-minute sessions in groups of four to six participants. Conditioned pain modulation (CPM), temporal summation (TS), and pressure pain thresholds (PPTs) were assessed at baseline and at three-month follow-up. Secondary outcome measures were the Fibromyalgia Impact Questionnaire, Pain Catastrophizing Scale, and Pain Anxiety Symptoms Scale. Results There were significant between-group differences for NPRS in favor of the groups receiving high-dose PNE, with a large effect size at three-month follow-up (P &lt; 0.01, η2p = 0.170), but there were no significant differences between groups for the remaining variables (P &gt; 0.05). All groups improved for central nociceptive processing, psychological variables, disability, and pain intensity (NPRS). Conclusions In patients with fibromyalgia, higher dosages of PNE produced a larger improvement in pain severity at three-month follow-up than other dosages of PNE and biomedical education. However, PNE was not superior to biomedical education in the central nociceptive processing, disability, or psychological variables in patients with fibromyalgia.

Background: Conditioned pain modulation (CPM) methods are experimental procedures to assess presumed descending nociceptive modulatory pathways. Various CPM-methods are currently used, making the comparison of results difficult. The aim of this study was to compare five conditioning stimuli and to evaluate the influencing effects of personal factors on CPM-efficacy. Methods: 101 healthy pain-free adults (50 males, 51 females) participated in this cross-sectional study with repeated measures design. The CPM-method consisted of hot water immersion (46°C, HWI), cold pressor test (12°C, CPT), cold pack application, and single and double ischemic occlusion as conditioning stimuli in randomized order. Pressure pain threshold was used as test stimulus at the mm. trapezius and quadriceps for all CPM-protocols. Results: All CPM-protocols resulted in effective CPM, although cold pack application revealed smaller CPM-magnitudes compared to all other methods at both muscles, except single ischemic occlusion at the m. quadriceps. A smaller CPM-effect at the m. trapezius was shown when CPM was provoked by single ischemic occlusion compared to the CPT. Chronic stress, gender, attentional focus, age, physical activity and perceived pain are all influencing factors, in various conditioning stimuli at the mm. trapezius and quadriceps. Conclusions: CPT and HWI seem to be the most appropriate conditioned pain modulation paradigms for research settings, while single and double ischemic occlusion seem to be more useful for clinical settings. Influencing factors to be considered are gender, age, stress, physical activity, perceived pain and attentional focus to the conditioning stimulus, but depend on the test site and exerted method. Significance: Hot water immersion, cold pressor test, and single and double ischemic occlusion result in comparable CPM-effects at the mm. trapezius and quadriceps. Anti-nociceptive effects of the cold pack are mainly a result of attention towards the cold pack. Chronic stress, attentional focus towards the conditioning stimulus and perceived pain of the conditioning stimulus influenced the anti-nociceptive effects at the m. trapezius. Gender and level of physical activity influenced the anti-nociceptive effects with the other methods at the m. quadriceps.