Estimation of Lumbar Spine Loading of Low Back Pain Participant During Lifting Using an Open Source Musculoskeletal Model.

Biomechanical modeling of spinal load during lifting in OpenSim has the potential for rehabilitation and clinical assessment. In the literature, several spinal models have been developed and validated with movement data from healthy individuals. Although these models are valid for predicting spinal load in healthy individuals, it is unknown whether these models are applicable for people with chronic low back pain (CLBP). This study aims to compare the application of the lifting full body (LFB) model between a healthy participant and a participant with CLBP. The participants performed the lifting activity, and the motion capture data was used to analyze how an open-source model predicts the loading of the lumbar spine. Peak spinal loading at L5/S1 joint was estimated as 3.9 kN for the healthy participant and 3.1 kN for the CLBP participant. The results suggest that a longer duration of lift and lower lumbar range of motion reduces lumbar spinal loading.

Wearable Nanocomposite Sensor System for Motion Phenotyping Chronic Low Back Pain: A BACPAC Technology Research Site.

Chronic low back pain (cLBP) is a prevalent and multifactorial ailment. No single treatment has been shown to dramatically improve outcomes for all cLBP patients, and current techniques of linking a patient with their most effective treatment lack validation. It has long been recognized that spinal pathology alters motion. Therefore, one potential method to identify optimal treatments is to evaluate patient movement patterns (ie, motion-based phenotypes). Biomechanists, physical therapists, and surgeons each utilize a variety of tools and techniques to qualitatively assess movement as a critical element in their treatment paradigms. However, objectively characterizing and communicating this information is challenging due to the lack of economical, objective, and accurate clinical tools. In response to that need, we have developed a wearable array of nanocomposite stretch sensors that accurately capture the lumbar spinal kinematics, the SPINE Sense System. Data collected from this device are used to identify movement-based phenotypes and analyze correlations between spinal kinematics and patient-reported outcomes. The purpose of this paper is twofold: first, to describe the design and validity of the SPINE Sense System; and second, to describe the protocol and data analysis toward the application of this equipment to enhance understanding of the relationship between spinal movement patterns and patient metrics, which will facilitate the identification of optimal treatment paradigms for cLBP.

Intramuscular Circulation of the Lumbar Multifidus in Different Trunk Positions on Standing.

A deficiency in lumbar muscle blood circulation is considered to be a major risk factor for non-specific low back pain. The aim of this study was to investigate changes in relative circulation over time in the lumbar multifidus in different positions on sitting.Twelve healthy subjects (7 males, 5 females, average age: 20.9 years) without low back pain for the past 12 months were recruited. Near-infrared spectroscopy (NIRS) was used to non-invasively measure total haemoglobin (Total-Hb) and oxygenated haemoglobin (Oxy-Hb) in the lumbar multifidus at the L5-S1 segment. Subjects were asked to move into either 60-degree trunk-flexed or 20-degree trunk-extended position from the starting (standing in neutral) position in 3 s, timed by a metronome, and to maintain these positions for 30 s. The measurements of Total-Hb and Oxy-Hb were compared at -3 (neutral position), 0, 10, 20, and 30 s in each flexed and extended position on sitting.In flexion, Total-Hb and Oxy-Hb of the lumbar multifidus were significantly decreased from a neutral (-3 s) to flexed (0 s) position (Total-Hb: p = 0.002, Oxy-Hb: p = 0.004); however, there were no significant differences in the flexed position. In extension, Total-Hb and Oxy-Hb of the lumbar multifidus were significantly increased from 0 to 10 s (Total-Hb: p < 0.001, Oxy-Hb: p < 0.001); however, there were no significant differences from the neutral (-3 s) to extended (0 s) position, or from 10 to 30 s.The results of this study indicate that the intramuscular circulation of the lumbar multifidus decreases immediately once the trunk starts moving into a flexed position on sitting. On the other hand, the intramuscular circulation of the lumbar multifidus increases for up to 10 s once the trunk starts moving into an extended position.

Postural Hypervigilance and Perception of Correct Sitting Posture in Individuals With and Without Low Back Pain / Hipervigilância postural e percepção da postura correta sentada em indivíduos com e sem dor lombar

Abstract Objectives To verify if there is a difference in postural hypervigilance in sitting in individuals with and without low back pain. Additionally, to observe whether there is a difference in the perception of correct sitting posture between individuals with low back pain and without low back pain. Methods The present study has a cross-sectional observational design, as a sample size of 92 individuals, later divided equally into two groups (with low back pain and without low back pain). Two instruments were used: the hypervigilance scale to analyze the frequency that volunteers correct their sitting posture during the day, and posture scans to investigate the perception of volunteers about the correct sitting posture. The data were submitted to the Shapiro-Wilk Normality test. To compare the values of Hypervigilance Scale, the Mann-Whitney, Chi-Square, and Fisher Exact tests were used to assess correct sitting posture. Results There was no significant difference between postural hypervigilance in sitting between individuals with low back pain and without low back pain. There was no significant difference between the choice of correct sitting posture between the group of individuals with and without low back pain. Conclusion There is no difference between the choice of correct sitting posture and the amount of postural hypervigilance in individuals with or without low back pain.

Resumo Objetivos Verificar se há diferença na hipervigilância postural sentada em indivíduos com e sem dor lombar. Além disso, observar se há diferença na percepção da postura correta sentada entre indivíduos com dor lombar e sem dor lombar. Métodos O presente estudo possui delineamento observacional transversal, como tamanho amostral de 92 indivíduos, posteriormente divididos igualmente em dois grupos (com dor lombar e sem dor lombar). Foram utilizados dois instrumentos: a escala de hipervigilância para analisar a frequência que voluntários corrigem a postura sentada no dia; e o quadro de posturas para investigar a percepção dos voluntários sobre a postura correta sentada. Os dados foram submetidos ao teste de Normalidade de Shapiro-Wilk. Para comparar os valores da Escala de Hipervigilância foi utilizado o teste de Mann-Whitney e o teste Qui-quadrado e exato de Fisher para avaliação da postura correta sentada. Resultados Não houve diferença significativa entre a hipervigilância postural sentada entre indivíduos com dor lombar e sem dor lombar. Não houve diferença significativa entre a escolha da postura correta sentada entre o grupo de indivíduos com e sem dor lombar. Conclusão Não há diferença entre a escolha da postura correta sentada e quantidade de hipervigilância postural em indivíduos com ou sem dor lombar.

Motor cortex excitability in chronic low back pain.

Chronic pain is associated with dysfunctional cortical excitability. Research has identified altered intracortical motor cortex excitability in Chronic Lower Back Pain (CLBP). However, research identifying the specific intracortical changes underlying CLBP has been met with inconsistent findings. In the present case-control study, we examined intracortical excitability of the primary motor cortex using transcranial magnetic stimulation (TMS) in individuals with CLBP. Twenty participants with CLBP (Mage = 54.45 years, SDage = 15.89 years) and 18 age- and gender-matched, pain-free controls (M = 53.83, SD = 16.72) were included in this study. TMS was applied to the hand motor area of the right hemisphere and motor evoked potentials (MEPs) were recorded from the first dorsal interosseous muscle of the contralateral hand. Resting motor threshold (rMT) and MEP amplitude were measured using single-pulse stimulation. Short interval intracortical inhibition (SICI) and intracortical facilitation (ICF) were assessed using paired-pulse stimulation. Individuals with CLBP had significantly higher rMT (decreased corticospinal excitability) and lower ICF compared to controls. No significant differences were found in MEP amplitude and SICI. These findings add to the growing body of evidence that CLBP is associated with deficits in intracortical modulation involving glutamatergic mechanisms.

Association of Functional Disability and Biopsychosocial Factors in Older Adults With Low Back Pain Who Live in the Amazonas State Brazil: A Cross-Sectional Study.

OBJECTIVE: The purpose of this study was to identify social and clinical factors associated with levels of functional disability (FD) in older adults with low back pain (LBP) in the city of Manaus, Amazonas, Brazil. METHODS: A cross-sectional study of 557 adults with LBP aged ≥60 years was completed. Sociodemographic and clinical features, pain intensity (Numeric Rating Scale), FD (Roland Morris Disability Questionnaire), physical activity (International Physical Activity Questionnaire-short version), body mass index, educational level, health perception, emotional level, and self-reported diseases were evaluated. Statistical analysis was used to verify the association between quantitative variables and a group; Student t test or Mann-Whitney test, and analysis of variance (normality assumption) or Kruskal-Wallis test (non-parametric), P value of less than .05. RESULTS: There were 81.3% female participants, 54.9% self-reported their race and/or skin color as brown, and 37.8% were sedentary. Pain intensity scores were 6.26 ± 2.19 in female participants and 5.82 ± 1.84 in male participants. Mean FD scores were 11.68 ± 6.08 for female participants and 9.61 ± 5.76 for males participants, although 39.7% of the total group presented with severe disability (score ≥14) and FD was associated with female sex (P = .001), physical activity (P≤ 0.001), body mass index (P≤ .001), emotional level (P < .001), and health perception (P < .001). CONCLUSION: In this group of older adults with LBP, FD was associated with female sex, level of physical activity, body mass index, emotional level, and health perception. Many factors that were identified with FD are modifiable; therefore, interventions, such as nutrition education and re-conceptualization of self-emotional and health perception, may have potential to help in preventing and reducing FD.

Dolor lumbar en el embarazo, aspectos fisiopatológicos y tratamiento / Low back pain in pregnancy, pathophysiological aspects and treatment

INTRODUCCIÓN: El dolor lumbar es una condición de alta prevalencia en la población general. La gestación genera cambios fisiológicos que favorecen la aparición de síntomas dolorosos que pueden comprometer la calidad de vida. MÉTODO: Revisión de la literatura con términos MeSH en inglés y español en las bases de datos Embase, PubMed, Lilacs, Sage, Google Academics y Scielo desde el año 1994 hasta el año 2021. Se encontraron 74 artículos y fueron seleccionados 50, basados en su impacto clínico. RESULTADOS: El dolor lumbar afecta a más del 50% de las mujeres embarazadas. Existen antecedentes gineco-obstétricos que pueden intervenirse para disminuir el riego o la intensidad de los síntomas. El diagnóstico es clínico, pero puede asociarse a imágenes diagnósticas cuando se sospechan condiciones de riesgo. El tratamiento se basa en intervenciones no farmacológicas como ejercicio y terapia física, pero pueden utilizarse algunos medicamentos e intervenciones en dolor según su riesgo-beneficio materno y fetal. CONCLUSIONES: El dolor lumbar en el embarazo es muy frecuente y debe ser conocido, diagnosticado y tratado por los profesionales de la salud que atienden esta población, dentro de un equipo multidisciplinario de tratamiento.

INTRODUCTION: Low back pain is a condition of high prevalence in the general population. Gestation generates physiological changes that favor the appearance of painful symptoms that can compromise the quality of life. METHOD: Review of the literature with MeSH terms in English and Spanish in the databases Embase, PubMed, Lilacs, Sage, Google Academics and Scielo from the year 1994 to the year 2021. Seventy-four articles were found and 50 were selected based on their clinical impact. RESULTS: Low back pain affects more than 50% of pregnant women. There are gyneco-obstetric antecedents that can be intervened to reduce the risk or intensity of symptoms. The diagnosis of this entity is clinical, but it can be associated with diagnostic imaging when risk conditions are suspected. Treatment is based on non-pharmacological interventions such as exercise and physical therapy, but some medications and pain interventions can be used according to their risk of maternal and fetal benefit. CONCLUSIONS: Low back pain in pregnancy is very frequent, it should be known, diagnosed, and treated by health professionals who care for this population, based on a multidisciplinary treatment team.

Chronic pain precedes disrupted eating behavior in low-back pain patients.

Chronic pain is associated with anhedonia and decreased motivation. These behavioral alterations have been linked to alterations in the limbic brain and could explain the increased risk for obesity in pain patients. The mechanism of these behavioral changes and how they set in in relation to the development of chronic pain remain however poorly understood. Here we asked how eating behavior was affected in low-back pain patients before and after they transitioned to chronic pain, compared to patients whose pain subsided. Additionally, we assessed how the hedonic perception of fat-rich food, which is altered in chronic pain patients, related to the properties of the nucleus accumbens in this patients' population. We hypothesized that the accumbens would be directly implicated in the hedonic processing of fat-rich food in pain patients because of its well-established role in hedonic feeding and fat ingestion, and its emerging role in chronic pain. Accordingly, we used behavioral assays and structural brain imaging to test sub-acute back pain patients (SBP) and healthy control subjects at baseline and at approximately one-year follow-up. We also studied a sample of chronic low-back pain patients (CLBP) at one time point only. We found that SBP patients who recovered at follow-up (SBPr) and CLBP patients showed disrupted eating behaviors. In contrast, SBP patients who persisted in having pain at follow-up (SBPp) showed intact eating behavior. From a neurological standpoint, only SBPp and CLBP patients showed a strong and direct relationship between hedonic perception of fat-rich food and nucleus accumbens volume. This suggests that accumbens alterations observed in SBPp patients in previous works might protect them from hedonic eating disruptions during the early course of the illness. We conclude that disrupted eating behavior specifically sets in after pain chronification and is accompanied by structural changes in the nucleus accumbens.

Altered effective connectivity within the cingulo-frontal-parietal cognitive attention networks in chronic low back pain: a dynamic causal modeling study.

Dysfunction of the cingulo-frontal-parietal (CFP) cognitive attention network has been associated with the pathophysiology of chronic low back pain (cLBP). However, the direction of information processing within this network remains largely unknown. We aimed to study the effective connectivity among the CFP regions in 36 cLBP patients and 36 healthy controls by dynamic causal modeling (DCM). Both the resting-state and task-related (Multi-Source Interference Task, MSIT) functional magnetic resonance imaging (fMRI) data were collected and analyzed. The relationship between the effective connectivity of the CFP regions and clinical measures was also examined. Our results suggested that cLBP had significantly altered resting-state effective connectivity of the prefrontal cortex (PFC)-to-mid-cingulate cortex (MCC) (increased) and MCC-to-left superior parietal cortex (LPC) (decreased) pathways as compared with healthy controls. MSIT-related DCM suggested that the interference task could significantly increase the effective connectivity of the right superior parietal cortex (RPC)-to-PFC and RPC-to-MCC pathways in cLBP than that in healthy controls. The control task could significantly decrease the effective connectivity of the MCC-to-LPC and MCC-to-RPC pathways in cLBP than that in healthy controls. The endogenous connectivity of the PFC-to-RPC pathway in cLBP was significantly lower than that in healthy controls. No significant correlations were found between the effective connectivity within CFP networks and pain/depression scores in patients with cLBP. In summary, our findings suggested altered effective connectivity in multiple pathways within the CFP network in both resting-state and performing attention-demanding tasks in patients with cLBP, which extends our understanding of attention dysfunction in patients with cLBP.

Effect of Kinesio taping on Pregnancy-related low back pain: A protocol for systematic review and meta-analysis.

BACKGROUND: Pregnancy-related low back pain (PLBP) affects the daily living activities of pregnant women, even leading to fetal agitation and threatened abortion. Kinesio taping (KT) can improve the circulation of blood and provide elastic supports, which is a reliable method to treat low back pain. At present, although many studies have been published on the effects of KT on PLBP, the results are inconsistent, and some studies even report that KT does not affect PLBP. there is still a lack of high-level clinical evidence for the treatment of PLBP with KT. Therefore, this study proposes a protocol for a systematic review and meta-analysis of published Randomized Controlled Trials (RCTs) to evaluate the efficacy and safety of KT for PLBP. METHODS: This protocol is guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols. We will search the following database sources of the RCTs: PubMed, the Cochrane Library, EMBASE, Web of Science, Chinese Biomedical Literature Database (CBM), Chinese National Knowledge Infrastructure Database (CNKI), Chinese Science, and the Wanfang Database. From the establishment of the database to April 2021. The retrieval word adopts the combination of theme words and free words. Take "Kinesiotape, Tape Athletic, Orthotic Tape, Athletic Tape, Pregnancy, Pregnancies, Gestation, low back pain" as a term for retrieval. Two independent investigators will conduct an electronic literature search, study selection, data extraction, and quality assessment to summarize and evaluate the efficacy of KT in the treatment of PLBP. Retrospective trials are not included, and the risk of bias will be assessed using the Cochrane bias risk tool. All data analysis will be conducted using Revman5.3 software. RESULTS: Quality outcomes in systematic review studies depend on inclusion and search criteria to obtain high-quality data, as well as how the data are processed and interpreted. Among the results, this study will objectively and comprehensively evaluate the efficacy and safety of the randomized controlled trial of KT in the treatment of PLBP, and make a detailed analysis of the effect of KT in the treatment of PLBP. The results will be analyzed by the Visual Analogue Scale of Pain and the Roland Morris Dysfunction Questionnaire. If applicable, a subgroup analysis will also be performed, which will be grouped according to the duration of pregnancy, grade of pain, etc. Finally, the results are submitted to a peer-reviewed journal for publication. CONCLUSION: Based on the results, this study will analyze and summarize the effect of KT on improving PLBP. It includes whether KT can improve the pain and lumbar function of PLBP, or it has adverse effects and reactions on pregnant women, then analysis and interpretation of other related issues. It is expected that the results of this study will provide a reference to the method and time of taping for clinical staff, as well as high-quality evidence to resolve the effect of KT on low back pain and provide corresponding guidance for pregnant women with low back pain. It aims to improve the status of low back pain in pregnant women and improve their physical health. PROTOCOL REGISTRATION NUMBER: PROSPERO CRD42021250373; https://clinicaltrials.gov/.

Fundamentals of Intervertebral Disc Degeneration.

Lumbar disc degeneration is one of the leading causes of chronic low back pain. The degenerative cascade is often initiated by an imbalance between catabolic and anabolic processes in the intervertebral discs. As a consequence of extracellular matrix degradation, neoinnervation and neovascularization take place. Ultimately, this degenerative process results in disc bulging and loss of nucleus pulposus and water content and subsequent loss of disc height. Most patients respond to conservative management and surgical interventions well initially, yet a significant number of patients continue to suffer from chronic low back pain. Because of the high prevalence of long-term discogenic pain, regenerative biological therapies, including gene therapies, growth factors, cellular-based injections, and tissue-engineered constructs, have attracted significant attention in light of their potential to directly address the degenerative process. Understanding the pathophysiology of degenerative disc disease is important in both refining existing technologies and developing innovative techniques to reverse the degenerative processes in the discs. In this review, we aimed to cover the underlying pathophysiology of degenerative disc disease as well as its associated risk factors and give a comprehensive summary about the developmental, structural, radiological, and biomechanical properties of human intervertebral discs.

The Relationship Between Pain-Related Threat and Motor Behavior in Nonspecific Low Back Pain: A Systematic Review and Meta-Analysis.

OBJECTIVE: Although pain-related fear and catastrophizing are predictors of disability in low back pain (LBP), their relationship with guarded motor behavior is unclear. The aim of this meta-analysis was to determine the relationship between pain-related threat (via pain-related fear and catastrophizing) and motor behavior during functional tasks in adults with LBP. METHODS: This review followed PRISMA guidelines. MEDLINE, Embase, PsychINFO, and CINAHL databases were searched to April 2021. Included studies measured the association between pain-related fear or pain catastrophizing and motor behavior (spinal range of motion, trunk coordination and variability, muscle activity) during movement in adults with nonspecific LBP. Studies were excluded if participants were postsurgery or diagnosed with specific LBP. Two independent reviewers extracted all data. The Newcastle-Ottawa Scale was used to assess for risk of bias. Correlation coefficients were pooled using the random-effects model. RESULTS: Reduced spinal range of motion during flexion tasks was weakly related to pain-related fear (15 studies, r = -0.21, 95% CI = -0.31 to -0.11) and pain catastrophizing (7 studies, r = -0.24, 95% CI = -0.38 to -0.087). Pain-related fear was unrelated to spinal extension (3 studies, r = -0.16, 95% CI = -0.33 to 0.026). Greater trunk extensor muscle activity during bending was moderately related to pain-related fear (2 studies, r = -0.40, 95% CI = -0.55 to -0.23). Pain catastrophizing, but not fear, was related to higher trunk activity during gait (2 studies, r = 0.25, 95% CI = 0.063 to 0.42). Methodological differences and missing data limited robust syntheses of studies examining muscle activity, so these findings should be interpreted carefully. CONCLUSION: This study found a weak to moderate relationship between pain-related threat and guarded motor behavior during flexion-based tasks, but not consistently during other movements. IMPACT: These findings provide a jumping-off point for future clinical research to explore the advantages of integrated treatment strategies that target both psychological and motor behavior processes compared with traditional approaches.

The Manual Therapy and Strengthening for the Hip (MASH) Trial: Protocol for a Multisite Randomized Trial of a Subgroup of Older Adults With Chronic Back and Hip Pain.

OBJECTIVE: Chronic low back pain (CLBP) is a disabling and costly condition for older adults that is difficult to properly classify and treat. In a cohort study, a subgroup of older adults with CLBP who had elevated hip pain and hip muscle weakness was identified; this subgroup differentiated itself by being at higher risk for future mobility decline. The primary purpose of this clinical trial is to evaluate whether a hip-focused low back pain (LBP) treatment provides better disability and physical performance outcomes for this at-risk group compared with a spine-focused LBP treatment. METHODS: This study is a multisite, single-blinded, randomized controlled, parallel arm, Phase II trial conducted across 3 clinical research sites. A total of 180 people aged between 60 and 85 years with CLBP and hip pain are being recruited. Participants undergo a comprehensive baseline assessment and are randomized into 1 of 2 intervention arms: hip-focused or spine-focused. They are treated twice weekly by a licensed physical therapist for 8 weeks and undergo follow-up assessments at 8 weeks and 6 months after randomization. Primary outcome measures include the Quebec Low Back Disability Scale and the 10-Meter Walk Test, which are measures of self-report and performance-based physical function, respectively. IMPACT: This multicenter, randomized clinical trial will determine whether a hip-focused or spine-focused physical therapist intervention results in improved disability and physical performance for a subgroup of older adults with CLBP and hip pain who are at increased risk of mobility decline. This trial will help further the development of effective interventions for this subgroup of older adults with CLBP.

Somatosensory behavioral alterations in a NGF-induced persistent low back pain model.

Low back pain (LBP) is a major global burden in part due to the underlying pathophysiological mechanisms being poorly understood. A LBP rat model involving two injections of nerve growth factor (NGF, an endogenous pain-related neurotrophin) into trunk musculature was recently developed. Additional behavioral work in this NGF-LBP rat model is required to better characterize local and remote somatosensory alterations related to NGF-induced peripheral and central sensitization. This work characterizes the time-dependent development of hypersensitivity to trunk and hindpaw cutaneous mechanical stimulation and deep muscle mechanical hyperalgesia in adult male Sprague-Dawley rats (n = 6/group). Behavioral assays were performed at baseline (Day 0, D0), D2, D5 (pre- and 4 h post-2nd NGF or control injection), D7, D10, and D14 in NGF and control groups. Trunk and hindpaw cutaneous mechanical hypersensitivity were tested using von Frey filaments. Deep trunk mechanical hyperalgesia was determined using a small animal algometer. NGF rats demonstrated increased cutaneous sensitivity to ipsilateral trunk mechanical stimuli at D7, D10, and D14. NGF rats also demonstrated ipsilateral deep mechanical hyperalgesia on D2, D5 + 4 h, D7, D10, and D14. Cutaneous hypersensitivity was delayed compared to deep hyperalgesia in NGF rats. No additional sensory changes were noted. Together, these results indicate that male mechanical somatosensory changes develop primarily locally in the ipsilateral trunk following unilateral NGF injections. These findings contrast with a previous report in female rats using this NGF-LBP model showing more widespread (bilateral) hyperalgesia and remote mechanical hypersensitivity. Future studies will examine potential sex-related pain behavioral differences in the NGF model.

Low Somatosensory Cortex Excitability in the Acute Stage of Low Back Pain Causes Chronic Pain.

Determining the mechanistic causes of complex biopsychosocial health conditions such as low back pain (LBP) is challenging, and research is scarce. Cross-sectional studies demonstrate altered excitability and organization of the somatosensory and motor cortex in people with acute and chronic LBP, however, no study has explored these mechanisms longitudinally or attempted to draw causal inferences. Using sensory evoked potential area measurements and transcranial magnetic stimulation derived map volume we analyzed somatosensory and motor cortex excitability in 120 adults experiencing acute LBP. Following multivariable regression modelling with adjustment for confounding, we identified lower primary (OR = 2.08, 95% CI = 1.22-3.57) and secondary (OR = 2.56, 95% CI = 1.37-4.76) somatosensory cortex excitability significantly increased the odds of developing chronic pain at 6-month follow-up. Corticomotor excitability in the acute stage of LBP was associated with higher pain intensity at 6-month follow-up (B = -0.15, 95% CI: -0.28 to -0.02) but this association did not remain after confounder adjustment. These data provide evidence that low somatosensory cortex excitability in the acute stage of LBP is a cause of chronic pain. PERSPECTIVE: This prospective longitudinal cohort study design identified low sensorimotor cortex excitability during the acute stage of LBP in people who developed chronic pain. Interventions that target this proposed mechanism may be relevant to the prevention of chronic pain.

Voluntary running attenuates behavioural signs of low back pain: dimorphic regulation of intervertebral disc inflammation in male and female SPARC-null mice.

OBJECTIVE: To examine the effect of running exercise on behavioral measures of pain and intervertebral disc (IVD) inflammation in the SPARC-null mouse model. METHODS: Male and female 8-month old SPARC-null and age-matched control mice received a home cage running wheel or a control, fixed wheel for 6 months. Behavioral assays were performed to assess axial discomfort (grip test) and radiating leg pain (von Frey, acetone tests) and voluntary running was confirmed. Expression of inflammatory mediators (TNF-α, IL-1ß, IL-2, IL-10, CCL5, CXCL1, CXCL5, RANKL, M-CSF, and VEGF) in IVDs was determined. Additional inflammatory (IL-1ß, IL-1Ra, CXCR1, CXCR2) and macrophage phenotypic markers (ITGAM, CD80, CD86, CD206, Arg1) in IVDs were investigated by qPCR. RESULTS: Voluntary running attenuated behavioral measures of pain in male and female SPARC-null mice. Increases in mediators including IL-1ß, CXCL1 and CXCL5 were observed in SPARC-null compared to control IVDs. After 6 months of running, increases in M-CSF and VEGF were observed in male SPARC-null IVDs. In females, pro-inflammatory mediators, including CXCL1 and CXCL5 were downregulated by running in SPARC-null mice. qPCR analysis further confirmed the anti-inflammatory effect of running in female IVDs with increased IL-1Ra mRNA. Running induced upregulation of the macrophage marker ITGAM mRNA in males. CONCLUSIONS: Voluntary running reversed behavioral signs of pain in male and female mice and reduced inflammatory mediators in females, but not males. Thus, the therapeutic mechanism of action may be sex-specific.

The brain's structural differences between postherpetic neuralgia and lower back pain.

The purpose is to explore the brain's structural difference in local morphology and between-region networks between two types of peripheral neuropathic pain (PNP): postherpetic neuralgia (PHN) and lower back pain (LBP). A total of 54 participants including 38 LBP and 16 PHN patients were enrolled. The average pain scores were 7.6 and 7.5 for LBP and PHN. High-resolution structural T1 weighted images were obtained. Both grey matter volume (GMV) and morphological connectivity (MC) were extracted. An independent two-sample t-test with false discovery rate (FDR) correction was used to identify the brain regions where LBP and PHN patients showed significant GMV difference. Next, we explored the differences of MC network between LBP and PHN patients and detected the group differences in network properties by using the two-sample t-test and FDR correction. Compared with PHN, LBP patients had significantly larger GMV in temporal gyrus, insula and fusiform gyrus (p < 0.05). The LBP cohort had significantly stronger MC in the connection between right precuneus and left opercular part of inferior frontal gyrus (p < 0.05). LBP patients had significantly stronger degree in left anterior cingulate gyrus and left rectus gyrus (p < 0.05) while had significantly weaker degree than PHN patients in left orbital part of middle frontal gyrus, left supplementary motor area and left superior parietal lobule (p < 0.05). LBP and PHN patients had significant differences in the brain's GMV, MC, and network properties, which implies that different PNPs have different neural mechanisms concerning pain modulation.

The Effects of Elgucare on Degenerated Intervertebral Disc-Induced Low Back Pain and Disc Regeneration: A Clinical Trial.

INTRODUCTION: Chronic low back pain (LBP) has a wide range of causes. However, most cases are induced by degeneration of the lumbar intervertebral discs (IVDs), and the aching caused by local compression of the affected region has considerable impacts on quality of life. This clinical trial investigated the use of Elgucare, a Chinese herbal formula, as a food supplement to reduce the pain of patients with LBP induced by degeneration of the lumbar IVDs. METHODS: The study assessed patient subjective quality of life, functional limitations caused by LBP, and variations in pain. The assessment was done through the visual analogue scale (VAS) and effects on lumbar IVD thickness, water content, and bone mineral density (BMD). These parameters were evaluated before and after the administration of Elgucare or a placebo, one of which was taken by each participant for a 12-month period. RESULTS: Elgucare reduced the patients' mean VAS pain score by 2.25 points and improved their mean LBP-hampered mobility as assessed by the Roland-Morris Questionnaire by 5.17 points. The results of another questionnaire indicated that Elgucare slowed the LBP-induced deterioration of patients' quality of life, while objective assessment indices obtained through X-ray and magnetic resonance imaging showed that the height and water retention of their IVDs were increased. However, the BMD results showed no improvements. CONCLUSIONS: Elgucare can increase the water retention and height of IVDs and reduce LBP, thereby enhancing quality of life. Therefore, Elgucare can potentially be used as a clinical supplement.

Car seat impact on driver's sitting behavior and perceived discomfort during prolonged real driving on varied road types.

Prolonged driving under real conditions can entail discomfort linked to driving posture, seat design features, and road properties like whole-body vibrations (WBV). This study evaluated the effect of three different seats (S1 = soft; S2 = firm; S3 = soft with suspension system) on driver's sitting behavior and perceived discomfort on different road types in real driving conditions. Twenty-one participants drove the same 195 km itinerary alternating highway, city, country, and mountain segments. Throughout the driving sessions, Contact Pressure (CP), Contact Surface (CS), Seat Pressure Distribution Percentage (SPD%) and Repositioning Movements (RM) were recorded via two pressure mats installed on seat cushion and backrest. Moreover every 20 minutes, participants rated their whole-body and local discomfort. While the same increase in whole-body discomfort with driving time was observed for all three seats, S3 limited local perceived discomfort, especially in buttocks, thighs, neck, and upper back. The pressure profiles of the three seats were similar for CP, CS and RM on the backrest but differed on the seat cushion. The soft seats (S1 & S3) showed better pressure distribution, with lower SPD% than the firm seat (S2). All three showed highest CP and CS under the thighs. Road type also affected both CP and CS of all three seats, with significant differences appearing between early city, highway and country segments. In the light of these results, automotive manufacturers could enhance seat design for reduced driver discomfort by combining a soft seat cushion to reduce pressure peaks, a firm backrest to support the trunk, and a suspension system to minimize vibrations.

Extracorporeal Shockwave Therapy for Treating Chronic Low Back Pain: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

OBJECTIVE: To assess the effectiveness and safety of extracorporeal shockwave therapy (ESWT) for the treatment of chronic low back pain (CLBP). METHODS: This was a systematic review and meta-analysis of randomized controlled trials (RCTs) designed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement standard. We identified relevant studies by searching multiple electronic databases, trial registries, and websites up to April 30, 2021, and examining reference lists. We selected RCTs that compared ESWT, in unimodal or multimodal therapeutic approaches, with sham ESWT or other active therapies. Two investigators independently extracted data and assessed the risk of bias and quality of the evidence. The main outcomes were pain intensity and disability status, examined as standardized mean differences (SMD) with 95% confidence intervals (CI). The risk of bias was assessed by using Cochrane Back and Neck (CBN) Group risk of bias tool and Jadad score, and GRADE was applied to determine the confidence in effect estimates. Heterogeneity was explored using sensitivity analysis and meta-regression. RESULTS: Ten RCTs, including a total of 455 young to middle-aged individuals (29.2-55.8 years), were identified. Compared with control, the ESWT group showed lower pain intensity at month 1 (SMD = -0.81, 95% CI -1.21 to -0.42), as well as lower disability score at month 1 (SMD = -1.45, 95% CI -2.68 to -0.22) and at month 3 (SMD = -0.69, 95% CI -1.08 to -0.31). No serious shockwave-related adverse events were reported. CONCLUSION: The use of ESWT in CLBP patients results in significant and quantifiable reductions in pain and disability in the short term. However, further well-conducted RCTs are necessary for building high-quality evidence and promoting the application of ESWT in clinical practice.