Volume 18, Issue 2

Background and aims: Central neuraxial blocks (CNB: epidural, spinal and their combinations) and other spinal pain procedures can cause serious harm to the spinal cord in patients on antihaemostatic drugs or who have other risk-factors for bleeding in the spinal canal. The purpose of this narrative review is to provide a practise advisory on how to reduce risk of spinal cord injury from spinal haematoma (SH) during CNBs and other spinal pain procedures. Scandinavian guidelines from 2010 are part of the background for this practise advisory. Methods: We searched recent guidelines, PubMed (MEDLINE), SCOPUS and EMBASE for new and relevant randomised controlled trials (RCT), case-reports and original articles concerning benefits of neuraxial blocks, risks of SH due to anti-haemostatic drugs, patient-related risk factors, especially renal impairment with delayed excretion of antihaemostatic drugs, and specific risk factors related to the neuraxial pain procedures. Results and recommendations: Epidural and spinal analgesic techniques, as well as their combination provide superior analgesia and reduce the risk of postoperative and obstetric morbidity and mortality. Spinal pain procedure can be highly effective for cancer patients, less so for chronic non-cancer patients. We did not identify any RCT with SH as outcome. We evaluated risks and recommend precautions for SH when patients are treated with antiplatelet, anticoagulant, or fibrinolytic drugs, when patients’ comorbidities may increase risks, and when procedure-specific risk factors are present. Inserting and withdrawing epidural catheters appear to have similar risks for initiating a SH. Invasive neuraxial pain procedures, e.g. spinal cord stimulation, have higher risks of bleeding than traditional neuraxial blocks. We recommend robust monitoring routines and treatment protocol to ensure early diagnosis and effective treatment of SH should this rare but potentially serious complication occur. Conclusions: When neuraxial analgesia is considered for a patient on anti-haemostatic medication, with patient-related, or procedure-related risk factors, the balance of benefits against risks of bleeding is decisive; when CNB are offered exclusively to patients who will have a reduction of postoperative morbidity and mortality, then a higher risk of bleeding may be accepted. Robust routines should ensure appropriate discontinuation of anti-haemostatic drugs and early detection and treatment of SH. Implications: There is an on-going development of drugs for prevention of thromboembolic events following surgery and childbirth. The present practise advisory provides up-to-date knowledge and experts’ experiences so that patients who will greatly benefit from neuraxial pain procedures and have increased risk of bleeding can safely benefit from these procedures. There are always individual factors for the clinician to evaluate and consider. Increasingly it is necessary for the anaesthesia and analgesia provider to collaborate with specialists in haemostasis. Surgeons and obstetricians must be equally well prepared to collaborate for the best outcome for their patients suffering from acute or chronic pain. Optimal pain management is a prerequisite for enhanced recovery after surgery, but there is a multitude of additional concerns, such as early mobilisation, early oral feeding and ileus prevention that surgeons and anaesthesia providers need to optimise for the best outcome and least risk of complications.

Background and aims: This double-blind (DB), randomized, placebo-controlled, sequential-group, multiple-ascending dose, phase 1 study evaluated safety, pharmacokinetics and pharmacodynamics of JNJ-39439335 in healthy men (part 1), and in participants with knee osteoarthritis (part 2). Methods: Both parts 1 and 2 consisted of screening (upto 21 days), 21-day DB treatment phase [eight participants/group: JNJ-39439335 (part 1: 2–50 mg; part 2: 10–50 mg): n =6; placebo: n =2] and follow-up (total study duration ~10 weeks). Results: Plasma concentrations and systemic exposure of JNJ-39439335 increased in slightly higher than dose-proportional fashion (steady-state reached by day 14). Renal excretion of JNJ-39439335 was negligible. Marked dose-related increases in pharmacodynamic heat pain assessments were observed in JNJ-39439335-treated participants, which persisted throughout the treatment with no signs of tolerance with repeated dosing. No effect on pharmacodynamic cold pain or mechanical pain assessments were seen. Effects on pharmacodynamic capsaicin-induced flare assessments in JNJ-39439335-treated participants versus placebo were consistent with effects observed with single-dose, and did not demonstrate tolerance with multiple dosing. In participants with knee osteoarthritis, significant improvements versus placebo were observed in a stair-climbing-induced pain model. All JNJ-39439335-treated participants reported ≥1 treatment-emergent adverse events (TEAE); most common (≥50% incidence) TEAEs in part 1 were feeling hot (79%), thermohypoesthesia (71%), paresthesia (58%) and feeling cold (50%), and in part 2, were minor thermal burns (50%). Conclusions: JNJ-39439335 (doses 2–50 mg) was well-tolerated, and associated with acceptable multiple-dose pharmacokinetic profile. JNJ-39439335 demonstrated sustained pharmacodynamic effects (heat pain perception, heat pain latency, capsaicin-induced flare), and an efficacy signal in participants with osteoarthritis pain. Implications: Given the efficacy signal observed and the unique safety profile, larger phase 2 studies are needed to better understand the potential of JNJ-39439335 in the treatment of chronic pain. Analgesic efficacy of lower doses administered over a longer period of time and improved patient counseling techniques to reduce the minor thermal burns can be explored to minimize the adverse events.

Background and aims: Pain assessment in intensive care is challenging, especially when the patients are sedated. Sedated patients who cannot communicate verbally are at risk of suffering from pain that remains unnoticed without careful pain assessment. Some tools have been developed for use with sedated patients. The Behavioral Pain Scale (BPS), the Critical-Care Pain Observation Tool (CPOT) and the Nonverbal Adult Pain Assessment Scale (NVPS) have shown promising psychometric qualities. We translated and culturally adapted these three tools for the Finnish intensive care environment. The objective of this feasibility study was to test the reliability of the three pain assessment tools translated into Finnish for use with sedated intensive care patients. Methods: Six sedated intensive care patients were videorecorded while they underwent two procedures: an endotracheal suctioning was the nociceptive procedure, and the non-nociceptive treatment was creaming of the feet. Eight experts assessed the patients’ pain by observing video recordings. They assessed the pain using four instruments: the BPS, the CPOT and the NVPS, and the Numeric Rating Scale (NRS) served as a control instrument. Each expert assessed the patients’ pain at five measurement points: (1) right before the procedure, (2) during the endotracheal suctioning, (3) during rest (4) during the creaming of the feet, and (5) after 20 min of rest. Internal consistency and inter-rater reliability of the tools were evaluated. After 6 months, the video recordings were evaluated for testing the test-retest reliability. Results: Using the BPS, the CPOT, the NVPS and the NRS, 960 assessments were obtained. Internal consistency with Cronbach’s alpha coefficient varied greatly with all the instruments. The lowest values were seen at those measurement points where the pain scores were 0. The highest scores were achieved after the endotracheal suctioning at rest: for the BPS, the score was 0.86; for the CPOT, 0.96; and for the NVPS, 0.90. The inter-rater reliability using the Shrout-Fleiss intraclass correlation coefficient (ICC) tests showed the best results after the painful procedure and during the creaming. The scores were slightly lower for the BPS compared to the CPOT and the NVPS. The test-retest results using the Bland-Altman plots show that all instruments gave similar results. Conclusions: To our knowledge, this is the first time all three behavioral pain assessment tools have been evaluated in the same study in a language other than English or French. All three tools had good internal consistency, but it was better for the CPOT and the NVPS compared to the BPS. The inter-rater reliability was best for the NVPS. The test-retest reliability was strongest for the CPOT. The three tools proved to be reliable for further testing in clinical use. Implications: There is a need for feasible, valid and reliable pain assessment tools for pain assessment of sedated ICU patients in Finland. This was the first time the psychometric properties of these tools were tested in Finnish use. Based on the results, all three instruments could be tested further in clinical use for sedated ICU patients in Finland.

Background and aims: Whiplash-Associated Disorders (WAD) are characterized by great variability in long-term symptoms. Patients with central neck and movement-induced stabbing pain participated in a randomized study comparing cervical fusion and multimodal rehabilitation. As reported in our previous paper, more patients treated by cervical fusion than by rehabilitation experienced pain relief. Although patient reported outcome measures are a core component of outcome evaluation, independent examiner has been recommended. Because of the heterogeneity of WAD complaints the patients in our study were examined at baseline and follow-up by four experts representing neurology, orthopedics, psychology and physical medicine. The aim was to compare the professional assessments of change both regarding the possible impact of the different examiners’ perspectives on individual patient’s outcome, and also on the analysis of possible outcome differences between the treatment groups. Methods: WAD patients with long-term neck pain as the predominant symptom after a traffic accident were eligible. The neck pain origin should be in the midline and perceived as dull and aching, with sudden movement inducing midline stabbing pain. Of the 1,052 patients in contact with our team, 49 were eligible. The overall treatment effect was evaluated on a global outcome transitional scale. The criteria for the scale categories were defined by each expert’s professional perspective on change in the whiplash complaints. Statistical methods that take account of the non-metric properties of ordered categorical data were used. Observed inter-expert disagreement was evaluated by the Svensson method that identifies and measures systematic group-related disagreement separately from disagreement caused by individual variation. Possible differences in the distributions of assessments on the expert-specific outcome scales between the treatment groups were analyzed by the Kruskal-Wallis test. Results: The per-protocol evaluation showed that a majority of the 18 patients who underwent fusion surgery were assessed as somewhat or much better, ranging from 67% to 78% depending on the expert. Corresponding proportions of improvement in the 17 patients treated by multimodal rehabilitation ranged from 29% to 53%. The statistical analyses confirmed better outcomes in the patients treated by fusion surgery, with p -values ranging from 0.003 to 0.04. The experts’ assessments of intra-patient change disagreed more or less for all patients. The analyses of the paired comparisons confirmed that these disagreements could most probably be explained by the different profession-specific operational definitions of the outcome scales rather than by individual variations in data. Conclusions: The multi-dimensional complexity of WAD-related complaints was comprehensively demonstrated by the inter-disciplinary disagreements in assessing intra-patient outcomes. The superiority of positive treatment effects in patients who underwent cervical fusion compared with multimodal rehabilitation was evident to all experts. Implications: The results strengthen our previous opinion that neck pain in this subgroup of WAD patients has a somatic origin. More than one examiner is recommended for multi-dimensional outcome assessments.

Background and aims: Chronic widespread pain (CWP) is associated with poor quality of sleep, but the detailed underlying mechanisms are still not fully understood. In this study we investigated the influence of CWP on morning cortisol and fasting glucose concentrations as well as sleep disordered breathing. Methods: In this case-control study, subjects with CWP ( n =31) and a control group without CWP ( n =23) were randomly selected from a population-based cohort of women. Current pain intensity, sleep quality, excessive daytime sleepiness [Epworth sleepiness scale (ESS)], psychiatric comorbidity and occurrence of restless legs syndrome (RLS) were assessed. Overnight polygraphy was applied to quantify sleep apnoea, airflow limitation and attenuations of finger pulse wave amplitude (>50%) as a surrogate marker for increased skin sympathetic activity. Morning cortisol and fasting glucose concentrations were determined. Generalised linear models were used for multivariate analyses. Results: CWP was associated with higher cortisol (464±141 vs. 366±111 nmol/L, p =0.011) and fasting glucose (6.0±0.8 vs. 5.4±0.7 mmol/L, p =0.007) compared with controls. The significance remained after adjustment for age, body mass index, RLS and anxiety status (β=122±47 nmol/L and 0.89±0.28 mmol/L, p =0.009 and 0.001, respectively). The duration of flow limitation in sleep was longer (35±22 vs. 21±34 min, p =0.022), and pulse wave attenuation was more frequent (11±8 vs. 6±2 events/h, p =0.048) in CWP subjects compared with controls. RLS was associated with higher ESS independent of CWP (β=3.1±1.3, p =0.018). Conclusions: Elevated morning cortisol, impaired fasting glucose concentration and increased skin sympathetic activity during sleep suggested an activated adrenal medullary system in subjects with CWP, which was not influenced by comorbid RLS. Implications: CWP is associated with activated stress markers that may deteriorate sleep.

Background and aims: Chronic pain is the frequent and significantly challenging complications in persons with spinal cord injury (SCI). Socio-cultural background may lead people perceive and manage pain differently. The study aims to describe the chronic pain experience and pain management of SCI persons in Nepal. Methods: A descriptive cross sectional study was conducted among purposively selected sample of 120 SCI persons with chronic pain living in the eight districts of Bagmati Zone of Nepal. The data were collected using the International Spinal Cord Injury Pain Basic Data Set Version 2 (ISCIPBDS-2) and Open-ended Pain Management Questionnaire. The data were analyzed using descriptive statistics and content analysis method. Results: The back ( n =84), lower legs/feet ( n =63) and buttocks/hips ( n =51) was found as the common pain locations. In common, the onset of pain was found within the first 6 month of the injury. Overall pain intensity and pain interference were found to be at the moderate level. The SCI persons used pain medications and non-pharmacological pain management. Ibuprofen was the commonly used pain medication and commonly used non-pharmacological pain management methods included physical support (e.g. massage, exercise), relaxation (e.g. distraction, substance abuse), coping (e.g. acceptance, praying), and traditional herbs. Conclusions: SCI persons had chronic pain experience which interfered with their daily living. They used pain medications and non-pharmacological pain management methods based on their beliefs, knowledge, and community resources in Nepal. Implications: This study provides some evidence to help the team of rehabilitation professional to plan and help SCI persons with chronic pain. Based on these findings, chronic pain management intervention for SCI persons should be developed and supported continuously from hospital to home based community context of Nepal.

Background and aims: Nonspecific chronic low back pain is a multifactorial biopsychosocial health problem where accurate assessments of pain, function and movement are vital. There are few reliable and valid assessment tools evaluating movement quality, hence the aim was to investigate nonspecific chronic low back pain patients’ movement patterns with the Standardised Mensendieck Test. Methods: Twenty patients (mean age=41, SD=9.02) with nonspecific chronic low back pain were examined with the Standardised Mensendieck Test whilst being videotaped and compared with 20 healthy controls. A physiotherapist, blinded to participant’s group belonging, scored Standardised Mensendieck Test videos according to the standardised manual. Associations between movement quality, fear of movement and re(injury) i.e. kinesiophobia and pain intensity were also investigated. Results: Patients scored significantly poorer than the controls in all 5 Standardised Mensendieck Test domains ( p <0.001). The biggest difference was observed with regard to movement pattern domain. In women we also found a difference in the respiration pattern domain. Conclusions: The Standardised Mensendieck Test was able to detect significant differences in quality of movement between patients and healthy controls. These results indicate that the Standardised Mensendieck Test may be a valuable examination tool in assessment and treatment of nonspecific chronic low back pain patients. Further, longitudinal studies should investigate whether poor movement and respiration patterns are important factors in nonspecific chronic low back pain, e.g. as predictors and/or mediators of therapeutic effects.

Background and aims: Chronic pain affects an estimated 1 in 10 adults globally regardless of age, gender, ethnicity, income or geography. Chronic pain, a multifactorial problem requires multiple interventions. One intervention which demonstrates promising results to patient reported outcomes is pain education. However, patient perspective on pain education and its impact remains fairly unknown. A cross-sectional study involving individuals with chronic pain examined their perspectives on pain education; did it change their understanding about their pain and self-management and did it have any impact on their perceived pain intensity and recovery. Methods: The study complied with CHERRIES guidelines and the protocol was locked prior to data collection. Primary outcomes were pain intensity and participants’ expectation of recovery. Univariate and multiple logistic regressions were used to analyze the data. Results: Five hundred and seventy three people participated; full data sets were available for 465. Participants who observed changes in their pain cognition and self-management following pain education reported lower pain intensity and greater expectation of recovery than participants who did not observe changes to cognition and management. Conclusions: The results suggest that individuals who observed changes to pain cognition and self-management on receiving pain education reported lower pain intensity and higher expectations of recovery than their counterparts who did not perceive any changes to pain cognition and self-management. Implications: Pain intensity and expectations about recovery are primary considerations for people in pain. What influences these factors is not fully understood, but education about pain is potentially important. The results suggest that individuals who observed changes to pain cognition and self-management on receiving pain education reported lower pain intensity and higher expectations of recovery than their counterparts who did not perceive any changes to pain cognition and self-management. The results from this study highlight the importance of effective pain education focused on reconceptualization of pain and its management.

Background and aims: Provoked vestibulodynia (PVD) represent a longstanding pain syndrome that affects large numbers of women worldwide. However, no standardized guidelines for PVD treatment exist. In a cross-sectional pilot study we examined 30 PVD patients on multidimensional parameters including pain, psychological distress and quality of movement, in order to obtain a broader understanding of the somatic and psychological symptoms in PVD, and for the future to develop better interventions. Additionally, we compare the findings to previously published results regarding the same parameters in women with chronic pelvic pain (CPP). Methods: Thirty women with PVD recruited from a tertiary care university clinic of gynecology were assessed for demographic data, pain intensity (VAS), psychological distress (GHQ-30 and Tampa scale of Kinesophobia) and quality of movement (standardized Mensendieck test, SMT). Results: Average age of the PVD women was 24.7±3.60 years, 60% of them were in permanent relationships, all were nulliparous, none had been subjected to surgical procedures, 100% were working full or part time and 90% were educated to at least undergraduate level. Mean VAS score was 7.77±1.97 (mean±SD), kinesiophobia 24.4±3.95 and anxiety domain of GHQ-30 9.73±4.06. SMT scores were particularly low for the domains of respiration and gait (less than 50% of optimal scores). Conclusions: PVD women display reduced quality of movement, especially for gait and respiration patterns, increased level of anxiety and high average pain scores. These findings are similar to what we have previously reported in CPP patients. However, in contrast to CPP group, PVD women are on average younger, have higher work participation, higher education level and have not been subjected to surgical procedures. Implications: Since PVD women display similar, although somewhat less severe, symptom profile than CPP, we suggest that a multidimensional approach to treatment, such as “somatocognitive therapy” should be investigated in this group as it has previously been shown to be promising in treatment of CPP.

Background and aims: Pressure pain threshold (PPT) and PPT maps are commonly used to quantify and visualize mechanical pain sensitivity. Although PPT’s have frequently been reported from patients with knee osteoarthritis (KOA), the absolute and relative reliability of PPT assessments remain to be determined. Thus, the purpose of this study was to evaluate the test-retest relative and absolute reliability of PPT in KOA. For that purpose, intra- and interclass correlation coefficient (ICC) as well as the standard error of measurement (SEM) and the minimal detectable change (MDC) values within eight anatomical locations covering the most painful knee of KOA patients was measured. Methods: Twenty KOA patients participated in two sessions with a period of 2 weeks±3 days apart. PPT’s were assessed over eight anatomical locations covering the knee and two remote locations over tibialis anterior and brachioradialis. The patients rated their maximum pain intensity during the past 24 h and prior to the recordings on a visual analog scale (VAS), and completed The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and PainDetect surveys. The ICC, SEM and MDC between the sessions were assessed. The ICC for the individual variability was expressed with coefficient of variance (CV). Bland-Altman plots were used to assess potential bias in the dataset. Results: The ICC ranged from 0.85 to 0.96 for all the anatomical locations which is considered “almost perfect”. CV was lowest in session 1 and ranged from 44.2 to 57.6%. SEM for comparison ranged between 34 and 71 kPa and MDC ranged between 93 and 197 kPa with a mean PPT ranged from 273.5 to 367.7 kPa in session 1 and 268.1–331.3 kPa in session 2. The analysis of Bland-Altman plot showed no systematic bias. PPT maps showed that the patients had lower thresholds in session 2, but no significant difference was observed for the comparison between the sessions for PPT or VAS. No correlations were seen between PainDetect and PPT and PainDetect and WOMAC. Conclusions: Almost perfect relative and absolute reliabilities were found for the assessment of PPT’s for KOA patients. Implications: The present investigation implicates that PPT’s is reliable for assessing pain sensitivity and sensitization in KOA patients.

Background and aims: Approximately 20% of patients having total knee arthroplasty (TKA) will experience chronic postoperative pain. Recently, preoperative pain facilitation has been associated with chronic pain after TKA, and gabapentin has been shown to decrease pain facilitation. The current study is a secondary follow-up of a primary RCT investigating the effect of gabapentin on acute postoperative pain after TKA and exploring the effect of pre- and perioperative administration of gabapentin on chronic postoperative pain and psychological state 3–4 years after TKA. Methods: Patients scheduled for TKA were randomized to either gabapentin 1,300 mg/day, gabapentin 900 mg/day, or placebo daily from 2-h before and 6 days after operation. Pre- and 3–4 years postoperatively pain scores related to pain while walking, at rest, when flexing the hip or the knee were collected. At the same time, the pain catastrophizing scale (PCS) and hospital anxiety and depression scale subscales for anxiety (HADS-A) and depression (HADS-D) were collected. Results: Lower postoperative pain while walking, flexing the hip, and at rest were found compared with preoperative scores ( p <0.03), but these were not associated with gabapentin treatment ( p >0.19). Significantly lower postoperative PCS and HADS-A scores were seen compared with preoperative scores ( p <0.001), but these were not associated with gabapentin treatment ( p >0.55). Conclusions: The current study found that pre- and perioperative administrations of gabapentin do not influence the pain or psychological state 3–4 years after TKA. Implications: The current study does not support that short-term pre- and perioperative use of gabapentin can reduce the development of chronic postoperative pain after TKA.

Background and aims: Pain caused by infiltrating pancreatic cancer is complex in nature and may therefore be difficult to treat. In addition to conventional analgesics, neurolytic blockade of the coeliac plexus is often recommended. However, different techniques are advocated, and procedures vary, and the results may therefore be difficult to compare. Therefore strong evidence for the effect of this treatment is still lacking, and more studies are encouraged. Our aim was to describe our technique and procedures using a Computer Tomograph (CT) guided procedure with a dorsal approach and present the results. Methods: The procedures were performed in collaboration between a radiologist and an anaesthesiologist. All patients had advanced pancreatic cancer. The patients were placed in prone position on pillows, awake and monitored. Optimal placement of injection needles was guided by CT, and the radiologist injected a small dose of contrast as a control. When optimal needle position, the anaesthesiologist took over and completed the procedure. At first 40 mg methylprednisolone was injected to prevent inflammation. Thereafter a mixture of 99% ethanol diluted to 50% by ropivacaine 7.5 mg/mL to a total amount of 20–30 mL per needle was slowly injected. Repeated aspiration was performed during injection to avoid intravasal injection. Pain treatment and pain score was recorded and compared before and after the treatment. Results: Eleven procedures in 10 patients were performed. Age 49–75, mean 59 years. Median rest life time was 36 days (11–140). Significant reduction of analgesics was observed 1 week after the procedure, and most patients also reported reduction of pain. No serious side effects were observed. Conclusions: CT guided neurolytic celiac plexus blockade is a safe and effective treatment for intractable pain caused by advanced pancreatic cancer. Not all patients experience a significant effect, but the side effects are minor, and the procedure should therefore be offered patients experiencing intractable cancer related pain.

Background and aims: Excessive opioid prescribing can lead to adverse consequences including stockpiling, misuse, dependency, diversion and mortality. Increased prescriptions to post-operative inpatients as part of their discharge planning may be a significant contributor. Primary aims included comparing the amount of opioids prescribed, consumed, left unused and their relationship with pain and functionality. Methods: A total of 132 consecutive patients who underwent elective orthopaedic surgery were prospectively audited. Daily oral morphine equivalent (DME) of opioids prescribed was compared with opioids consumed and amount left unused 7–10 days after discharge. For analysis, patients were split into three groups: total knee replacement (TKR), hand surgery (Hands), and miscellaneous (Misc). Results: The mean dose of opioid prescribed per patient was 108.5 mg DME. TKR consumed 33–35% more opioids than Misc ( p =0.0283) and Hands ( p =0.0975). Age was a significant independent factor for opioid consumption in the 50th and 75th percentiles of Hands ( p ≤0.05). An average of 36 mg DME per patient was left unused with Hands having the highest median DME (37 mg) unused. In the total cohort, 26% of patients were discharged with more DME than their last 24 h as an inpatient and had at least 50% of their tablets left unused at follow-up. Conclusions: Over-prescription of opioids occurs at discharge which can increase the risk of harm. New intervention is needed to optimise prescribing practises. Implications: Changes to prescribing habits and workplace culture are required to minimise unnecessary opioid prescribing but will be challenging to implement. A multi-layered approach of electronic prescribing, opioid stewardship and targeted educational awareness programmes is recommended.

Background and aims: Patellofemoral pain (PFP) is a prevalent and debilitating musculoskeletal condition, considered to have a mechanical aetiology. As such, the physical impairments associated with PFP are well documented and have helped characterise different physical phenotypes. But little is known about the relationship between PFP and psychological well-being. In this study, we aimed to: (1) compare psychological profiles between groups with and without PFP; (2) compare psychological profiles and condition severity between PFP subgroups; and (3) explore relationships between psychological factors and their contribution to disability. We expected to find higher levels of psychological impairment, especially kinesiophobia and catastrophizing in the PFP group. We also expected to identify a sub-group for who worsening levels of disability correspond with worsening psychological well-being. Methods: One hundred participants with PFP (72 females, mean±SD age 27±5 years, BMI 25.3±4.8 kg/m 2 ) completed measures of pain, disability, and psychological features (kinesiophobia, catastrophizing, anxiety and depression). Fifty controls, matched by sex, age and activity level (36 females, age 27±5 years, BMI 22.9±4.5 kg/m 2 ) also completed psychological measures. The Knee injury and Osteoarthritis Outcome Score (KOOS) was used to cluster PFP participants (K-means cluster analysis) into more and less severe sub-groups. Differences between the control and PFP groups were analysed using t -tests, analysis of variance, Mann-Whitney U -tests or χ 2 tests as appropriate ( p <0.05). Pearson correlations were used to explore relationships between psychological measures. Backward stepwise regression ( p out >0.05) evaluated how the psychological factors potentially relate to disability. Results: Psychological features did not differ between PFP and pain-free groups. But differences were apparent when the PFP cohort was subgrouped. Compared to controls, the more-severe group had significantly higher levels of depression (MD 1.8, 95% CI 0.8–2.8; p ≤0.001) and catastrophizing (MD 5.7, 95% CI 2.4–9; p ≤0.001). When compared to less-severe cases, the more-severe group also demonstrated significantly higher levels of kinesiophobia (MD 4.3, 95% CI 2.1–6.5; p ≤0.001), depression (MD 1.5 95% CI 0.5–2.6; p =0.01) and catastrophizing (MD 4.9, 95% CI 1–8.8; p =0.01). The weakest relationship between psychological factors was found between kinesiophobia and anxiety ( r =0.29; p =0.02). While the strongest relationship existed between depression and anxiety ( r =0.52; p ≤0.001). Both kinesiophobia (β −0.27, 95% CI −0.265 to −0.274) and depression (β −0.22, 95% CI −0.211 to −0.228) were associated with disability as defined by the KOOS in the regression model ( R 2 =0.17, p ≤0.001). Conclusions: Those with more-severe PFP-related disability have higher levels of psychological impairment than less-severe cases. Kinesiophobia seems to stand as an important factor in the experience of PFP, because it was elevated in the PFP group, significantly differed between the PFP sub-groups and contributed to explaining disability. Contrary to our hypothesis, levels of catastrophizing in the PFP group and severe sub-group were low and seemingly not important. Implications: These findings draw attention to psychological factors to which clinicians assessing PFP should show vigilance. They also highlight psychological impairments that might be worthwhile targets in optimising PFP management.

Background and aims: Non-specific musculoskeletal pain symptoms are common in adolescents and may differ between the sexes, and be related to age and daily activities. It is critical to examine the prevalence and frequency of symptoms in adolescent students who tend to have pain which interferes with their routine activities. This study aimed to explore the prevalence and frequency of self-reported musculoskeletal pain symptoms by age and sex, and we also examined the association of symptoms with routine activities of school-age adolescents by area of pain. Methods: A cross-sectional survey was conducted among Thai students aged 10–19 years. All 2,750 students were asked to report previous 7-day and/or 12-month pain using the Standardized Nordic Questionnaire (Thai version) in 10 body areas. Multivariable logistic regression adjusted for age and sex was used to analyze the association between daily activity and musculoskeletal pain symptoms. Results: A total of 76.1% ( n =2,093) of students reported experiencing pain in the previous 7 days, 73.0% ( n =2,007) reported in the previous 12-month period and 83.8% ( n =2,304) reported pain in both 7-day and 12-month periods. The most common pain area was from a headache, with other areas being neck and shoulders, in that order, for both periods of time. The prevalence of musculoskeletal pain was especially higher in older groups and females. Participants reported frequency of pain as “sometimes in different areas” ranging from 78.4% to 88% and severity of pain at 3.82±2.06 out of 10 (95% CI 3.74–3.91). Routine daily activities associated with symptoms of headache, neck, shoulders, and ankles or feet pain were computer use (head, OR=2.22), school bag carrying (neck, OR=2.05), school bag carrying (shoulder, OR=3.09), and playing sports (ankle or foot, OR=2.68). Conclusions: The prevalence of musculoskeletal pain symptoms was high in both the previous 7-day and 12-month periods, especially in females and older adolescents, although most of them sometimes experienced pain. Computer use and school bag carrying were associated with headache, neck and shoulder pain, while playing sports was related to symptoms of the foot and ankle. Implications: The prevalence of pain was high, particularly in the older and female groups. Although they experienced mild symptoms sometimes, the related daily activities leading to these symptoms should be closely noticed.

Background and aims: Some low back pain (LBP) patients recover after every pain episode whereas others develop chronicity. Research indicates that the amount of atrophy and fat infiltration differs between patients with LBP. Also enhanced pain sensitivity is present only in a subgroup of LBP patients. The relationship between pain sensitivity and muscular deformations in LBP, is however unexplored. This study examined the association between pressure pain sensitivity and the structural characteristics of the lumbar muscles in three different groups of non-specific LBP patients. Methods: This cross-sectional study examined the total cross-sectional area (CSA), fat CSA, muscle CSA and muscle fat index (MFI) of the lumbar multifidus (MF) and erector spinae (ES) at level L4 by magnetic resonance imaging in 54 patients with non-specific LBP (23 recurrent LBP, 15 non-continuous chronic LBP and 16 continuous chronic LBP). Pressure pain thresholds were measured at four locations (lower back, neck, hand and leg) by a manual pressure algometer and combined into one “pain sensitivity” variable. As a primary outcome measure, the association between pain sensitivity and muscle structure characteristics was investigated by multiple independent general linear regression models. Secondly, the influence of body mass index (BMI) and age on muscle characteristics was examined. Results: A positive association was found between pain sensitivity and the total CSA of the MF ( p =0.006) and ES ( p =0.001), and the muscle CSA of the MF ( p =0.003) and ES ( p =0.001), irrespective of the LBP group. No association was found between pain sensitivity and fat CSA or MFI ( p >0.01). Furthermore, a positive association was found between BMI and the fat CSA of the MF ( p =0.004) and ES ( p =0.006), and the MFI of the MF ( p <0.01) and ES ( p =0.003). Finally, a positive association was found between age with the fat CSA of the MF ( p =0.008) but not with the fat CSA of the ES ( p >0.01), nor the MFI of the MF ( p >0.01) and ES ( p >0.01). Conclusions: A higher pain sensitivity is associated with a smaller total and muscle CSA in the lumbar MF and ES, and vice versa, but results are independent from the LBP subgroup. On the other hand, the amount of fat infiltration in the lumbar muscles is not associated with pain sensitivity. Instead, a higher BMI is associated with more lumbar fat infiltration. Finally, older patients with LBP are associated with higher fat infiltration in the MF but not in the ES muscle. Implications: These results imply that reconditioning muscular tissues might possibly decrease the pain sensitivity of LBP patients. Vice versa, therapy focusing on enhancement of pain sensitivity might also positively influence the CSA and that way contribute to the recovery of LBP. Furthermore, the amount of lumbar muscle fat seems not susceptible to pain sensitivity or vice versa, but instead a decrease in BMI might decrease the fat infiltration in the lumbar muscles and therefore improve the muscle structure quality in LBP. These hypothesis apply for all non-specific LBP patients, despite the type of LBP.

Background and aims: This study investigated whether young university students with neck pain (NP) have postural control deficits when compared to sex and age-matched asymptomatic subjects. Methods: Centre of pressure (COP) sway area, velocity, anterior-posterior and mediolateral distances were measured in participants with ( n =27) and without ( n =27) neck pain for different combinations of static standing (narrow stance, tandem stance and single leg stance) and measurement time (90, 60, 30 and 15 s) with eyes closed using a force plate. Additionally, static and dynamic clinical tests of postural control were used. Results: No significant between group differences were found for the COP measurements ( p >0.05). However, individuals with subclinical NP were more likely to fail the 90 s tandem test ( p <0.05) in the force plate and univariate comparisons revealed significant between group differences in the tandem and single leg stance clinical test measurements. Conclusions: Taken together, the inconsistent results might suggest an emerging postural control deficit in university students with low disability and low intensity chronic idiopathic NP.

Background and aims: Exercise-induced hypoalgesia (EIH) is a well-established phenomenon in pain-free individuals that describes a decrease in pain sensitivity after an acute bout of exercise. The EIH response has been demonstrated to be sub-optimal in the presence of persisting pain. Menstrual pain is a common recurrent painful problem with many women experiencing high levels of pain each cycle. However, the EIH response has not been examined in a cohort of women with high levels of menstrual pain. This research aimed to examine whether EIH manifests differently in women with varying levels of menstrual pain. The primary hypothesis was that women with high levels of menstrual pain would demonstrate compromised EIH. Secondary aims were to explore relationships between EIH and emotional state, sleep quality, body mass index (BMI) or physical activity levels. Methods: Pressure pain thresholds (PPT) were measured in 64 participants using a digital handheld algometer before and after a submaximal isometric-handgrip exercise. EIH index was compared between low (VAS 0–3), moderate (VAS 4–7) and high (VAS 8–10) pain groups, using a linear mixed model analysis with participant as a random effect, and site, menstrual pain category and the interaction between the two, as fixed effects. Results: EIH was consistently induced in all groups. However, there was no statistically significant difference between the pain groups for EIH index ( p =0.835) or for any co-variates ( p >0.05). Conclusions: EIH was not found to differ between women who report regular low, moderate or high levels of menstrual pain, when measured at a point in their menstrual cycle when they are pain free. Implications: This study provides insight that EIH does not vary in women with differing levels of menstrual pain when they are not currently experiencing pain. The current findings indicate that, although menstrual pain can involve regular episodes of high pain levels, it may not be associated with the same central nervous system dysfunctions as seen in sustained chronic pain conditions.

Background and aims: Exercise-induced hypoalgesia (EIH) and conditioned pain modulation (CPM) are assumed to reflect descending pain inhibition. Potential interactions between EIH and CPM may be important in the therapy of chronic pain, as reduced CPM and increased pain after exercise are frequently observed. This study compared the EIH response after CPM was activated using a cold pressor task with the EIH response after a control condition. Methods: Thirty-one participants (age: 27.7±9.8; 15 female) completed two sessions: a cold pressor task (CPT) session, i.e. testing EIH with preceding CPM activation induced using a 2 min CPT at approximately 2°C, and a control session, i.e. testing EIH after a control condition (2 min of quiet rest). EIH was induced using a 15 min bicycling exercise at a target heart rate corresponding to 75% VO2 max. Repeated measures ANOVAs on pressure pain thresholds (PPTs) at the hand, back and leg were used to determine the effects of exercise after the cold pressor test and control condition. Furthermore, correlations between CPM and EIH, in the CPT session as well as control session, were calculated at each assessment site. Results: A significant time x condition interaction (F(1, 30)=43.61, p <0.001, partial η 2 =0.59), with Bonferroni-corrected post-hoc t -tests showed that PPTs increased after exercise in the control session ( p <0.001), but not in the CPT session ( p =0.125). Furthermore, there was a small positive correlation of EIH in the control session and CPM at the hand (r=0.37, p =0.043). There was a moderate negative correlation of EIH in the CPT session and CPM at the hand (r=−0.50, p =0.004), and smaller negative correlations at the back (r=−0.37, p =0.036) and at the leg (r=−0.35, p =0.054). Conclusions: Attenuated EIH after the CPM activation in comparison to a control condition suggests that EIH and CPM may share underlying pain inhibitory mechanisms on a systemic level. This assumption is further supported by the finding of small to moderate significant correlations between EIH and CPM at the hand. The attenuated EIH response furthermore suggests that these mechanisms are exhaustible, i.e. that its effects decline after a certain amount of inhibition. Implications: In patients with chronic pain, assessing the current capacity of the descending pain inhibitory system – as indicated by the CPM response – may aid to make better predictions about how patients will respond to exercise with respect to acute pain reduction.

Background and aims: Non-specific neck pain (NsNP) constitutes a burden to the bearers and a management challenge to physiotherapists globally. Effectiveness of neck stabilisation and dynamic exercises in the management of NsNP has been documented, but it is not clear which exercise regimen is more effective in alleviating its associated pain, depression and anxiety. This study was carried out to compare the effectiveness of neck stabilisation and/or dynamic exercises on pain intensity, depression and anxiety among patients with NsNP. Methods: Eighty-nine consenting individuals with NsNP participated in this single-blind, randomised controlled trial. They were recruited from the outpatient physiotherapy clinics of the National Orthopaedic Hospital in Dala, Kano State, Nigeria. Participants were randomly assigned into one of three intervention groups: neck stabilisation exercise group (NSEG; n =30), neck dynamic exercise group (NDEG; n =28) and neck stabilisation and dynamic exercise group (NSDEG; n =31). Treatment was administered thrice weekly for 8 consecutive weeks. Variables were assessed at baseline, at the end of the fourth and eighth weeks. Pain intensity was assessed through the use of a visual analogue scale, while depression and anxiety were evaluated using both the Beck Depression Inventory and Beck Anxiety Inventory. The data was analysed using descriptive statistics, multivariate analysis of variance (MANOVA) and post hoc tests with Bonferroni adjustment at the p =0.05 significant level. Results: Ages of participants in NSEG (46.8±12.4 years), NDEG (48.6±11.6 years) and NSDEG (45.1±13.4 years) were comparable. The comparison for NSEG, NSDEG and NDEG within groups revealed that there was significant difference in pain intensity, depression and anxiety scores from baseline, in the fourth and eighth weeks of the study – (F=62.40, p =0.001, F=13.91, p =0.001 and F=20.93, p =0.001); (F=11.92, p =0.001, F=8.75, p =0.004 and F=9.70, p =0.001) and (F=36.63, p =0.001, F=11.99, p =0.001 and F=6.59, p =0.001), respectively. A group comparison of the pain intensity, depression and anxiety scores of participants in the NSEG, NSDEG and NDEG at the baseline of the study revealed that there were no significant differences in the pain intensity and depression and anxiety scores among the three groups: p =0.159, 0.58 and 0.179, respectively. At week 4 of the study, however, a significant difference in pain intensity and anxiety scores across the three groups was recorded – p =0.018, p =0.011, respectively, but no significant difference was noted in depression scores ( p =0.93). At week 8 of the study, it was determined that there were significant differences in pain intensity and depression scores p =0.001 and p =0.041, but no significant dissimilarities in the anxiety scores. Post hoc revealed that only pain was significant and lay with NSEG. Conclusions: The study concluded that the stabilisation, dynamic and stabilisation, plus dynamic exercises were effective in relieving pain and reducing depression and anxiety in patients with NsNP. However, stabilisation showed a more marked effect than the combination exercises of stabilisation plus dynamic exercises, and dynamic exercises in reducing pain intensity in patients with NsNP. Implications: It is recommended that stabilisation exercises be chosen over stabilisation plus dynamic exercises, or dynamic exercise, while treating patients with NsNP. However, both are effective.