Tibialis posterior muscle pain effects on hip,knee and ankle gait mechanics

BackgroundTibialis posterior (TP) dysfunction is a common painful complication in patients with rheumatoid arthritis (RA), which can lead to the collapse of the medial longitudinal arch. Different theories have been developed to explain the causality of tibialis posterior dysfunction. In all these theories, pain is a central factor, and yet, it is uncertain to what extent pain causes the observed biomechanical alterations in the patients. The aim of this study was to investigate the effect of experimental tibialis posterior muscle pain on gait mechanics in healthy subjects.MethodsTwelve healthy subjects were recruited for this randomized crossover study. Experimental pain was induced by ultrasound-guided injection of 1 mL hypertonic saline into the upper part of the right tibialis posterior muscle with the use of isotonic saline as non-pain-inducing control. Subsequently, kinematic data during three self-paced over ground walking for each condition were collected. Ground reaction forces and external moments were measured from force plates installed in the floor. Painful areas were evaluated using body charts and pain intensity scoring via a verbal numerical rating scale.FindingsDecreased hip internal rotation was observed during the pain condition at the end of the stance phase. There were no changes in gait velocity and duration of stand phase between the pain and no pain conditions. Reduced external joint moment was found for external knee rotation and for external hip rotation.InterpretationThe study has demonstrated that induced pain in the TP muscle evokes kinematic alteration in the hip and the knee joints, but not in the ankle, which suggest an underlying early stage joint compensatory mechanism. These findings suggest the need to include those joints in current physical evaluations of tibialis posterior dysfunction.     

Does experienced pain affects local brain volumes? Insights from a clinical acute pain model

Background/Objective:To study pain-brain morphometry associations as a function of post-surgery stages (anesthesia, pain and analgesia) in an acute pain model. Method:Impacted mandible third molar were extracted. Before surgery, an anatomical T1 scan was obtained. Regional brain volumen and subcortical nuclei shapes were obtained. Statistical analyses were done using multiple regression, being pain scores the predictors and voxel volumes, subcortical nuclei volumes and subcortical nuclei shapes, the outcomes. Results:Pain was significantly larger at pain than at anesthesia and analgesia stages, and was higher during anesthesia than during analgesia. Pain intensity was related to grey matter in several cortical (Insula, Mid Frontal and Temporal Gyruses, Precuneus, Anterior Cingulate), and subcortical nuclei (Hippocampus, Thalamus, Putamen, Amygdala), depending of the post-surgical stage. A larger number of brain areas showed significance at pain that at anesthesia and analgesia stages. Conclusions:The relationships of regional brain volumes and subcortical nuclei shapes with pain scores seemed to be unsteady, as they changed with the patient's actual pain stage.     

恐惧的代价：疼痛恐惧、心理忧虑和躯体化对疼痛感知预测作用的比较

首次在无痛群体中比较疼痛恐惧、心理忧虑和躯体化对疼痛感知的预测作用大小及调节和中介关系。以多个同类量表得分的Z分数加和作为三者的因子分,以冷压痛觉测验（CPT）疼痛指标（阈限、耐受性、强度、不愉快度）为目标变量,通过分层回归及调节和中介作用分析,发现疼痛恐惧对疼痛不愉快度的预测作用最强,心理忧虑对疼痛体验（强度、不愉快度）的预测作用被疼痛恐惧完全中介,躯体化只有在高疼痛恐惧条件下才显著负向预测疼痛不愉快度。综上,疼痛恐惧是三因素中预测CPT疼痛体验的主要因素。     

Pain,Care, and the Body: A Response to de Vignemont

Frédérique de Vignemont argues on the basis of several empirical counterexamples that Bain and Klein are wrong about the relationship between pain and bodily care. I argue that the force of the putative counterexamples is weak. Properly understood, the association between pain and care is preserved in a way that is consistent with both de Vignemont's own views and the empirical facts.     

Disintegration of the self and the regeneration of ‘psychic skin’ in the treatment of traumatized refugees

This paper presents a tentative understanding of the characteristics of the extreme traumas, elsewhere called ‘complex PTSD’, that some refugees and asylum‐seekers bring into therapy. It suggests that these kinds of traumas suffered during adulthood may involve a disintegration of the self and a loss of ‘psychic skin’. This conceptualization is derived from the treatment of a refugee who survived multiple extreme traumas and with whom efforts were made in therapy to identify a complex methodology making use of supplementary therapeutic tools in addition to individual psychotherapy. The case demonstrates how the disintegration of self implies not only a deep somato‐psychic dissociation, but also a loss of intrapsychic and interpersonal space. In the treatment this was worked through via repetition of the victim‐aggressor dynamics at multiple levels. In the end, the therapeutic context was structured like a set of concentric layers, creating a ‘bandage’ over the patient's wounds whilst his ‘psychic skin’ was able to regenerate. The conditions triggered by extreme traumas in refugees challenge some of the cornerstones of individual psychoanalytic technique, as well as the idea that individual therapy may be thought of as existing in an environmental vacuum.     

MICHEL DE M'UZAN AND ORIGINS OF IDENTITY

Michel de M'Uzan describes a way to think about identity in which two distinct sources of our sense of identity must be considered. His innovation is the concept of the vital‐identital, which he suggests is equally foundational with the sense of identity derived from the early human environment. The term endogenous identity is used to unify under one heading the ideas that de M'Uzan employs to build his concept of vital‐identital. The author summarizes de M'Uzan's earlier work, elaborates on his more recent ideas, and illustrates the use of de M'Uzan's ideas with a cultural and a clinical example.     

‘Sleeping beauties’: succession problems of adolescence

The author explores the succession problems of adolescence. She uses the Brothers Grimm’s fairy tale Sleeping Beauty to consider various characters and narratives possible in the analytic field during the succession process. Use of the characters in a fairy tale allows an analyst to play with the different roles the patient unconsciously assigns her. The author conceives of the avoidance of adolescent turbulence as a common reaction to adolescence, but one that can also become entrenched, and result in a restriction of emotional growth. The paper explores the psychic isolation of adolescence and the splitting required to manage the conflicting desires of the phase. The persistent absence of passion, including in the analytic process, constitutes a psychic retreat from developmental turbulence. The analyst of such an adolescent may need to allow them to be ‘somnolent’ for some time, but may eventually need to wake them (metaphorically) or even pierce the somnolent, avoidant state. The author uses clinical vignettes of late adolescents to demonstrate such transitions, exploring her countertransference experience as well as the reaction of adults to the succession process of adolescence.     

Goal equivalent manifold analysis of task performance in non-specific LBP and healthy subjects during repetitive trunk movement: Effect of load,velocity, symmetry

Motor abundance allows reliability of motor performance despite its variability. The nature of this variability provides important information on the flexibility of control strategies. This feature of control may be affected by low back pain (LPB) and trunk flexion/extension conditions.Goal equivalent manifold (GEM) analysis was used to quantify the ability to exploit motor abundance during repeated trunk flexion/extension in healthy individuals and people with chronic non-specific LBP (CNSLBP).Kinematic data were collected from 22 healthy volunteers and 22 CNSLBP patients during metronomically timed, repeated trunk flexion/extension in three conditions of symmetry, velocity, and loading; each at two levels. A goal function for the task was defined as maintaining a constant movement time at each cycle. Given the GEM, flexibility index and performance index were calculated respectively as amounts of goal-equivalent variability and the ratio of goal-equivalent to non-goal-equivalent variability.CNSLBP group was as similar as healthy individuals in both flexibility index (p = 0.41) and performance index (p = 0.24). Performance index was higher in asymmetric (p < 0.001), high velocity (p < 0.001), and loaded (p = 0.006) conditions.Performance and flexibility in using motor abundance were influenced by repeated trunk flexion/extension conditions. However, these measures were not significantly affected by CNSLBP.     

Negative beliefs about low back pain are associated with persistent high intensity low back pain

While previous cross-sectional studies have found that negative beliefs about low back pain are associated with pain intensity, the relationship between back beliefs and persistent low back pain is not well understood. This cohort study aimed to examine the role of back beliefs in persistent low back pain in community-based individuals. A hundred and ninety-two participants from a previous musculoskeletal health study were invited to take part in a two-year follow-up study. Beliefs about back pain were assessed by the Back Beliefs Questionnaire (BBQ) at baseline and low back pain intensity was measured by the Chronic Pain Grade Questionnaire at baseline and follow-up. Of the 150 respondents (78.1%), 16 (10.7%) reported persistent high intensity low back pain, 12 (8.0%) developed high intensity low back pain, in 16 (10.7%) their high intensity low back pain resolved and 106 (70.7%) experienced no high intensity low back pain. While participants were generally positive about low back pain (BBQ mean (SD) = 30.2 (6.4)), those with persistent high intensity pain reported greater negativity (BBQ mean (SD) = 22.6 (4.9)). Negative beliefs about back pain were associated with persistent high intensity low back pain after adjusting for confounders (M (SE) = 23.5 (1.6) vs. >30.1 (1.7), p < .001). This study found negative back beliefs were associated with persistent high intensity low back pain over 2 years in community-based individuals. While further longitudinal studies are required, these findings suggest that targeting beliefs in programs designed to treat and prevent persistent high intensity low back pain may be important.     

疼痛恐惧的神经机制及其消退

疼痛恐惧是疼痛基础和临床研究中的一个重要课题。个体对疼痛信息产生过度警觉,诱发不恰当的回避行为,扰乱机体的正常功能,加剧疼痛的现象即为疼痛恐惧。疼痛恐惧可影响个体的疼痛感知以及疼痛相关的注意和回避行为,且在慢性疼痛(如慢性肌骨骼疼痛)的发展、维持个体正常生理功能的丧失中起着重要作用。疼痛恐惧的形成与表达涉及杏仁核、海马、背侧前扣带回皮层、和前额叶皮层等脑区的参与。当前的疼痛恐惧消退的心理-行为干预方法可在疼痛恐惧加工的不同阶段(巩固、再巩固和消退)消退个体的疼痛恐惧。然而,由于恐惧记忆形成过程较为复杂并受多种因素影响,疼痛恐惧记忆消退方法效果较不稳定,其基础研究与临床应用之间仍存在较大的鸿沟。将来研究有必要考虑到疼痛恐惧形成环境的差异以及个体人格特质/心理状态的差异,逐步完善相关消退方法并将其引入临床镇痛,以期帮助患者弱化、擦除甚至改写困扰他们的疼痛恐惧,从而缓解甚至消除病患的疼痛。