Facial expression overrules lumbopelvic kinematics for clinical judgements regarding low back pain intensity

Through real-time behavioral observation systems, pain behaviors are commonly used by clinicians to estimate pain intensity in patients with low back pain. However, little is known about how clinicians rely on pain-related behaviors to make their judgment. According to the Information Integration Theory (IIT) framework, this study aimed at investigating how clinicians value and integrate information from lumbopelvic kinematics (LK), a protective pain behavior, and facial expression intensity (FEI), a communicative pain behavior, to estimate pain in patients with chronic low back pain (cLBP). Methods. Twenty-one experienced clinicians and twenty-one novice clinicians were asked to estimate back pain intensity from a virtual character performing a trunk flexion-extension task. Results. Results revealed that both populations relied on facial expression and that only half of the participants in each group integrated FEI and LK to estimate cLBP intensity. Among participants who integrated the two pain behaviors, averaging rule predominated among others. Results showed that experienced clinicians relied equally on FEI and LK to estimate pain, whereas novice clinicians mostly relied on FEI. Discussion. The use of additive rule of integration does not appear to be systematic when assessing others’ pain. When assessing pain intensity, communicative and protective pain behaviors may have different relevance

Effets d’une stratégie d’acceptation sur la tolérance à l’effort, la force maximale, la perception de l’effort et de la douleur, chez des personnes souffrant de lombalgie chronique : une étude pilote = Effects of an acute Mindfulness-based intervention on exercise tolerance, maximal strength, pain and effort-related experiences in individuals with primary chronic low back pain: a pilot study

Résumé Introduction : Cette étude examine les effets aigus d’une stratégie d’acceptation basée sur la pleine conscience sur la tolérance à l’effort, la force maximale, la perception de l’effort et de la douleur, chez des personnes souffrant de lombalgie chronique. Méthode : Les participants ont été répartis aléatoirement en deux groupes. Avant et après l’intervention expérimentale ou contrôle, un test de force maximale, un test de Sorensen, et des évaluations relatives à l’effort perçu et aux douleurs ressenties ont été réalisés. La dramatisation de la douleur, l’anxiété trait, la pleine conscience dispositionnelle, et l’impulsivité ont été contrôlées. Des tests-t et modèles à effets mixtes ont été utilisés pour traiter les données. Résultats : L’effort et le caractère désagréable de la douleur ont été significativement plus élevés après l’intervention. Contrairement aux participants du groupe expérimental, les participants du groupe contrôle ont réduit significativement leur force maximale et ont tendu vers une réduction de leur tolérance à l’effort au cours du temps. Discussion : Les résultats soulignent l’intérêt d’interventions basées sur la pleine conscience dans les adaptations à l’effort chez un public souffrant de douleurs chroniques. Les résultats nécessitent d’être répliqués avec des échantillons conséquents et en contrôlant les capacités fonctionnelles des participants. Abstract Introduction: This study investigated the effects of an acute mindfulness-based intervention on exercise tolerance, maximal voluntary contraction (MVC), pain and effort-related experiences in individuals with primary chronic low back pain. Method: Participants were randomly assigned to an experimental group and a control group. Before and after the intervention, participants completed a MVC test, a modified Sorensen test and numerical rating scales about pain intensity, pain unpleasantness, perceived effort and use of coping strategies. Dispositional measures such as pain catastrophizing, trait anxiety, dispositional mindfulness and impulsivity were also assessed. T-tests and linear mixed models were performed. Results: Participants from the control group significantly decreased their MVC across time and showed a trend towards a decrease in exercise tolerance over time, which was not the case for the experimental group. For both groups, pain unpleasantness and effort were perceived higher during the second modified Sorensen test. Analyses revealed neither significant effect of time nor group on pain intensity and the use of coping strategies. Discussion: The results highlight the value of involving individuals with primary chronic pain in mindfulness-based interventions to improve adaptations to effort while targeting referred pain. Larger samples and controlling for individuals’ functional status appear necessary for further research

Facial Expression Overrides Lumbopelvic Kinematics for Clinical Judgements about Low Back Pain Intensity

Background. Through real-time behavioral observation systems, pain behaviors are commonly used by clinicians to estimate pain intensity in patients with low back pain. However, little is known about how clinicians rely on pain-related behaviors to make their judgment. According to the Information Integration Theory (IIT) framework, this study aimed at investigating how clinicians value and integrate information from lumbopelvic kinematics (LK), a protective pain behavior, and facial expression intensity (FEI), a communicative pain behavior, to estimate pain in patients with chronic low back pain (cLBP). Methods. Twenty-one experienced clinicians and twenty-one novice clinicians were asked to estimate back pain intensity from a virtual character performing a trunk flexion-extension task. Results. Results revealed that both populations relied on facial expression and that only half of the participants in each group integrated FEI and LK to estimate cLBP intensity. Among participants who integrated the two pain behaviors, averaging rule predominated among others. Results showed that experienced clinicians relied equally on FEI and LK to estimate pain, whereas novice clinicians mostly relied on FEI. Discussion. The use of additive rule of integration does not appear to be systematic when assessing others’ pain. When assessing pain intensity, communicative and protective pain behaviors may have different relevance

Recovery of lignin and lignans enriched fractions from thermomechanical pulp mill process water through membrane separation technology: Pilot-plant study and techno-economic assessment

International audienceMembrane process is a viable option for valuable compounds such as lignin and lignans recovery in aqueous discharges of thermomechanical pulp industries. Recovery of lignin and lignans with continuous mode ultrafiltration/nanofiltration installation has not been studied in detail previously. After flotation used to remove lipophilic matter of pulp mill effluent, the three steps membrane process was composed of a clarification step by a 150 kDa ultrafiltration used to remove suspended matter, followed by two nanofiltrations of 1 kDa and 300 Da to respectively retain lignin and lignans. A techno-economic evaluation of this process has been performed. The process with a plant capacity of 60 m(3) h(-1) was able to produce 12 tons of lignin and 825 kg of lignans per month. The influence of plant capacity between 0.1 and 60 m(3) h(-1) on extracts production cost allows determining a production cost equal or below 10 V.kg(-1) as plant capacity reached 10 m(3) h(-1). Valorization of lignin and lignans as parts of the formulas of high added value products could allow thermomechanical plants to head towards biorefinery and cleaner production concepts. Furthemore, the 300 Da permeate possessed the required characteristics to be re used and save fresh water utilization. (C) 2019 Elsevier Ltd. All rights reserved

Fractionation of polyphenols from thermomechanical pulp mill process water by flotation and membrane integrated process

International audienceFractionation of phenolic compounds in thermomechanical pulp mills was performed with a coupling of a prior treatment realized by flotation and a ceramic membrane process. Two lines of membranes filtration were tested. After a common 150 kDa clarification, 1 kDa filtration was performed with or without previous 5 kDa filtration. Flotation was shown to be inevitable to retain lipophilic compounds which cause severe membrane fouling. 150 kDa permeate flux was 20% higher when process water was firstly floated and was around 260 L h−1 m−2. 1 kDa membrane was fouled with 31% of irreversible fouling without previous 5 kDa filtration and phenolic compounds purity reached only 26% in this 1 kDa permeate. Phenolic compounds as lignin-like substances which might be attached to hemicelluloses were recovered in 5 kDa retentate. Retentate of 1 kDa might contain a major fraction of lignin derivatives with molecular weights around 1 kDa free or linked with phenolic acids. Permeate of 1 kDa contained 14% of phenolic compounds such as lignans and free phenolic acids purified at 50%

Exercise for the prevention and treatment of low back, pelvic girdle and lumbopelvic pain during pregnancy: a systematic review and meta-analysis

Objective The purpose of this review was to investigate the relationship between prenatal exercise, and low back (LBP), pelvic girdle (PGP) and lumbopelvic (LBPP) pain. Design Systematic review with random effects meta-analysis and meta-regression. Data sources Online databases were searched up to 6 January 2017. Study eligibility criteria Studies of all designs were eligible (except case studies and reviews) if they were published in English, Spanish or French, and contained information on the population (pregnant women without contraindication to exercise), intervention (subjective or objective measures of frequency, intensity, duration, volume or type of exercise, alone [ exercise-only ] or in combination with other intervention components [eg, dietary; exercise + co-intervention ]), comparator (no exercise or different frequency, intensity, duration, volume and type of exercise) and outcome (prevalence and symptom severity of LBP, PGP and LBPP). Results The analyses included data from 32 studies (n=52 297 pregnant women). \u27Very low\u27 to \u27moderate\u27 quality evidence from 13 randomised controlled trials (RCTs) showed prenatal exercise did not reduce the odds of suffering from LBP, PGP and LBPP either in pregnancy or the postpartum period. However, \u27very low\u27 to \u27moderate\u27 quality evidence from 15 RCTs identified lower pain severity during pregnancy and the early postpartum period in women who exercised during pregnancy (standardised mean difference -1.03, 95% CI -1.58, -0.48) compared with those who did not exercise. These findings were supported by \u27very low\u27 quality evidence from other study designs. Conclusion Compared with not exercising, prenatal exercise decreased the severity of LBP, PGP or LBPP during and following pregnancy but did not decrease the odds of any of these conditions at any time point