Muscle Control and Non-specific Chronic Low Back Pain

Relation Between Abnormal Spontaneous Brain Activity and Altered Neuromuscular Activation of Lumbar Paraspinal Muscles in Chronic Low Back Pain

OBJECTIVE

To investigate the neural mechanism underlying functional reorganization and motor coordination strategies in patients with chronic low back pain (cLBP).

DESIGN

A case-control study based on data collected during routine clinical practice.

SETTING

This study was conducted at a university hospital.

PARTICIPANTS

Fifteen patients with cLBP and 15 healthy controls.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Whole brain blood oxygen level-dependent signals were measured using functional magnetic resonance imaging and amplitude of low-frequency fluctuation (ALFF) method to identify pain-induced changes in regional spontaneous brain activity. A novel approach based on the surface electromyogram (EMG) system and fine-wire electrodes was used to record EMG signals in the deep multifidus, superficial multifidus, and erector spinae.

RESULTS

In cLBP, compared with healthy groups, ALFF was higher in the medial prefrontal, primary somatosensory, primary motor, and inferior temporal cortices, whereas it was lower in the cerebellum and anterior cingulate and posterior cingulate cortices. Furthermore, the decrease in the average EMG activity of the 3 lumbar muscles in the cLBP group was positively correlated with the ALFF values of the primary somatosensory cortex, motor cortex, precuneus, and middle temporal cortex but significantly negatively correlated with the ALFF values of the medial prefrontal and inferior temporal cortices. Interestingly, the correlation between the functional activity in the cerebellum and the EMG activity varied in the lumbar muscles.

CONCLUSIONS

These findings suggest a functional association between changes in spontaneous brain activity and altered voluntary neuromuscular activation patterns of the lumbar paraspinal muscles, providing new insights into the mechanisms underlying pain chronicity as well as important implications for developing novel therapeutic targets of cLBP.

Systematic Review and Meta-analysis of Stimulation of the Medial Branch of the Lumbar Dorsal Rami for the Treatment of Chronic Low Back Pain

INTRODUCTION

Chronic low back pain (CLBP) is often associated with impaired motor control and degeneration of the lumbar multifidus muscles. Several studies have reported on the utility of multifidus or medial branch stimulation as a treatment. We present a systematic review and meta-analysis of studies reporting on the change in low back pain intensity with multifidus stimulation.

MATERIALS AND METHODS

A comprehensive literature search was conducted from 2010 to 2022 for randomized controlled trials or prospective reports in adults with CLBP, treated with multifidus or medial nerve stimulation through implanted or percutaneous device. Mean change (standard error) in pain intensity was extracted and data synthesized using a mixed effects regression with a random intercept for the study to account for repeated time points.

RESULTS

A total of 419 participants were enrolled in six studies; there were 25 effects (one to six time points per study), with follow-ups ranging from 1.5 to 48 months. The weighted pooled mean effect was a reduction in pain intensity (0-10 scale) of 2.9 units (95% CI: 2.1-3.7). The 95% prediction interval was a reduction in pain intensity of 0.6 to 5.2 units. The estimated probability of a reduction in pain of >two units in a new similar study is 0.84 (0.68-0.98). Meta-regression revealed that a longer follow-up time was associated with greater reductions in pain (0.25 units [0.16-0.34] per six months).

CONCLUSIONS

Medial branch stimulation for the treatment of CLBP shows a high probability of a clinically significant change in pain intensity. Longer duration of stimulation was associated with decreased low back pain intensities.

Adverse Childhood Experiences and Chronic Low Back Pain in Adulthood: The Role of Emotion Regulation

Chronic low back pain (cLBP) is characterized by biopsychosocial determinants that collectively result in a substantial burden at the individual, community, and health care system levels. A growing body of literature suggests that childhood adversity is longitudinally associated with the development and maintenance of various chronic pain conditions in adulthood. Little research has investigated the psychological processes that might underlie the association between adverse childhood experiences (ACEs) and cLBP. Emotion regulation comprises a substantive part of the subjective experience of pain and may be a potential mechanism through which ACEs contribute to cLBP etiology and maintenance. Thus, the current study examined the extent to which emotion dysregulation mediated the relationship between ACEs and pain severity (pain at rest and movement-evoked pain) in adults with cLBP. Participants included 183 adults (53.0% female, 62.5% non-Hispanic Black) between the ages of 18 and 85 with cLBP. Participants self-reported on ACEs, pain, difficulties in emotion regulation (DER), depression, and completed brief physical function tasks. In data analytic models, sociodemographic variables were included as covariates. Analyses revealed that emotion regulation mediated the relationship between ACEs and cLBP severity at rest (indirect effect = .15 [95% CI {.06-.25}]) and with movement (indirect effect = 1.50 [95% CI {.69-2.57}]). Findings suggest ACEs are linked to cLBP severity in adulthood through DER. This aligns with research demonstrating that childhood maltreatment can lead to DER, which perpetuate over the lifespan to impact adult health outcomes. PERSPECTIVE: This study presents emotion dysregulation as a psychological pathway through which childhood adversity may contribute to cLBP in adulthood. This work may bolster our understanding of social experiences as risk factors for chronic pain, while identifying targets for clinical intervention. TRIAL REGISTRATION: This study utilized baseline data collected as part of a parent trial titled "Examining Racial and SocioEconomic Disparities in Chronic Low Back Pain" (ClinicalTrials.gov ID: NCT03338192).

Association between seated trunk control and cortical sensorimotor white matter brain changes in patients with chronic low back pain

Trunk control involves integration of sensorimotor information in the brain. Individuals with chronic low back pain (cLBP) have impaired trunk control and show differences in brain structure and function in sensorimotor areas compared with healthy controls (HC). However, the relationship between brain structure and trunk control in this group is not well understood. This cross-sectional study aimed to compare seated trunk control and sensorimotor white matter (WM) structure in people with cLBP and HC and explore relationships between WM properties and trunk control in each group. Thirty-two people with cLBP and 35 HC were tested sitting on an unstable chair to isolate trunk control; performance was measured using the 95% confidence ellipse area (CEA95) of center-of-pressure tracing. A WM network between cortical sensorimotor regions of interest was derived using probabilistic tractography. WM microstructure and anatomical connectivity between cortical sensorimotor regions were assessed. A mixed-model ANOVA showed that people with cLBP had worse trunk control than HC (F = 12.96; p < .001; ηp2 = .091). There were no differences in WM microstructure or anatomical connectivity between groups (p = 0.564 to 0.940). In the cLBP group, WM microstructure was moderately correlated (|r| = .456 to .565; p ≤ .009) with trunk control. Additionally, the cLBP group demonstrated stronger relationships between anatomical connectivity and trunk control (|r| = .377 to .618 p < .034) compared to the HC group. Unique to the cLBP group, WM connectivity between right somatosensory and left motor areas highlights the importance of interhemispheric information exchange for trunk control. Parietal areas associated with attention and spatial reference frames were also relevant to trunk control. These findings suggest that people with cLBP adopt a more cortically driven sensorimotor integration strategy for trunk control. Future research should replicate these findings and identify interventions to effectively modulate this strategy.

The Neurostimulation Appropriateness Consensus Committee (NACC)®: Recommendations for Spinal Cord Stimulation Long-Term Outcome Optimization and Salvage Therapy

INTRODUCTION

The International Neuromodulation Society (INS) has recognized a need to establish best practices for optimizing implantable devices and salvage when ideal outcomes are not realized. This group has established the Neurostimulation Appropriateness Consensus Committee (NACC)® to offer guidance on matters needed for both our members and the broader community of those affected by neuromodulation devices.

MATERIALS AND METHODS

The executive committee of the INS nominated faculty for this NACC® publication on the basis of expertise, publications, and career work on the issue. In addition, the faculty was chosen in consideration of diversity and inclusion of different career paths and demographic categories. Once chosen, the faculty was asked to grade current evidence and along with expert opinion create consensus recommendations to address the lapses in information on this topic.

RESULTS

The NACC® group established informative and authoritative recommendations on the salvage and optimization of care for those with indwelling devices. The recommendations are based on evidence and expert opinion and will be expected to evolve as new data are generated for each topic.

CONCLUSIONS

NACC® guidance should be considered for any patient with less-than-optimal outcomes with a stimulation device implanted for treating chronic pain. Consideration should be given to these consensus points to salvage a potentially failed device before explant.

Effect of exercise and manual therapy or kinesiotaping on sEMG and pain perception in chronic low back pain: a randomized trial

The importance of incorporating lumbo-pelvic stability core and controlling motor exercises in patients with chronic low back pain (CLBP) reinforces the use of strategies to improve biopsychosocial beliefs by reducing biomedical postulations. However, clinical practice guidelines recommend multimodal approaches incorporating exercise and manual therapy (MT), and instead reject the application of kinesiotape (KT) in isolation. Therefore, the objectives of this study were to analyze the effects of 12 weeks of exercises combined with MT or KT on perceived low back pain using the visual analog scale (VAS) and muscle electric activity measured with electromyography (EMG) of the rectus abdominis and multifidus in CLBP (mild disability) and to explore the relationship between the rectus abdominis and multifidus ratios and pain perception after intervention. A blinded, 12-week randomized controlled trial (RCT) was carried out, involving three parallel groups of patients with CLBP. The study was registered at Clinicaltrial.gov and assigned the identification number NCT05544890 (19/09/22). The trial underwent an intention-to-treat analysis. The primary outcome revealed a multimodal treatment program supplemented by additional therapies such as MT and KT, resulting in significant reductions in perceived low back pain. The subjective assessment of individuals with CLBP indicated no discernible distinction between exclusive core stability exercises and control-motor training when combined with MT or KT. Notably, our findings demonstrated positive alterations in both the mean and peak EMG values of the right rectus abdominis in the exercise group, suggesting a beneficial impact on muscle activation. This study focused on assessing the activation levels of the trunk musculature, specifically the rectus abdominis (RA) and multifidus (MF), in individuals with CLBP exhibiting mild disability according to the Oswestry Disability Index. Importantly, improvements in the VAS values were observed independently of changes in muscle electrical activity.

Integrative rehabilitation in the treatment of lumbosacral muscle strain in elite trampoline athletes: a pilot study

Background

Lumbosacral muscle strain (LMS) is common in Chinese elite trampoline athletes. Advanced lumbar muscle activation is necessary for postural control before upper extremity voluntary movements, called anticipatory postural adjustment to reduce internal postural interference (IPI). The potential of delayed lumbar muscle activation has been reported in patients with non-specific LBP (NLBP) in response to IPI. However, it remains unknown whether this effect exists in elite trampoline athletes. There is also limited literature reporting the rehabilitation of LMS in this population. This study first aimed to explore whether elite trampoline athletes with LMS experience delayed activation of lumbar muscles under IPI. The secondary aim was to preliminarily evaluate an integrative rehabilitation program's effectiveness.

Materials and methods

Ten elite trampoline athletes with LMS were recruited and received 10 sessions of integrative rehabilitation, including extracorporeal shock wave therapy, acupuncture, Tui-na, and spine function exercises. At baseline and after all sessions, the relative activation time of the lumbar muscles under IPI in a modified rapid arm-rise test was used as a primary outcome measure. The secondary measures included a visual analog scale (VAS) and a questionnaire to assess low back pain (LBP) and athletic training performance.

Results

The relative activation time of the lumbar muscles under IPI was delayed at baseline, but significantly decreased after the intervention (P < 0.05). The VAS was significantly decreased after the intervention (P < 0.05). There was no significant correlation between the difference in VAS and in activation time of the lumbar muscles before and after the intervention (P > 0.05).

Conclusions

Elite trampoline athletes with LMS had delayed activation in their lumbar muscles under IPI. Integrative rehabilitation was effective in LBP relief and neuromuscular control of the lumbar muscles, and impacted positively on training performance. Future studies with a larger sample size, a control group, and long-term follow-ups are needed to further examine the efficacy of integrative rehabilitation in elite trampoline athletes with LMS. Additionally, the application of this approach in athletes with LMS or LBP in other sports, particularly those involving IPI, should be explored.

Comparison of erector spinae and gluteus medius muscle thickness and activation in individuals with and without low back pain

BACKGROUND

Dysfunctional patterns of the erector spinae (ES) and gluteus medius (GM) muscles often accompany episodes of low back pain (LBP). Rehabilitative ultrasound imaging (RUSI) has been used to measure ES and GM muscle thickness, however such measurements have not been compared in individuals with and without LBP.

OBJECTIVES

To compare ES and GM muscle thickness and change in thickness utilizing RUSI in individuals with and without LBP.

DESIGN

Cross-sectional comparison.

METHODS

A volunteer sample of 60 adults with (n = 30) and without (n = 30) LBP was examined. Thickness measurements of the ES and GM at rest and during contraction were obtained by using RUSI during a single session. Statistical comparison was performed using ANCOVA. The demographic variable age was used as a covariate in the primary comparative analysis.

RESULTS

Mean difference for age between groups was 5.4 years (95% CI: 1.85, 8.94, p = 0.004). Average ODI score was 32.33±6.58 and pain level of 5.39±0.73 over the last 24 h in the symptomatic group. There was a statistically significant difference in the percent thickness change in both the ES, mean difference = -3.46 (95% CI: -6.71, -0.21, p = 0.039) and GM, mean difference = -1.93 (95% CI: -3.85, -0.01, p = 0.049) muscles between groups.

CONCLUSIONS

Individuals with LBP may have reduced percent thickness change of the ES and GM muscles when compared to asymptomatic individuals.

Effects of a mat Pilates-based exercise program for low back pain in helicopter pilots of the Brazilian Air Force: Randomized controlled trial

INTRODUCTION

Helicopter pilots may present chronic low back pain due to vibration exposure and asymmetric posture during flight.

OBJECTIVES

To analyze the effects of a Pilates-based exercise program on low back pain of helicopter pilots of the Brazilian Air Force.

METHODS

This is a randomized controlled trial with fifteen helicopter pilots of the Brazilian Air Force, who were assessed for pain intensity (Numerical Pain Rating Scale), disability associated with low back pain, and spine muscle endurance in three positions: trunk extension (Ito test) and left and right lateral bridge. Individuals were randomly distributed into the regular exercises group (REG) (n = 7), oriented to maintain their exercise routine, and Pilates group (PG) (n = 8), which performed an exercise program based on Pilates method twice a week for 12 weeks. Reassessments occurred after 6 and 12 weeks. Data were analyzed on SPSS 20.0 software using a significance level of 5%.

RESULTS

PG showed a significant reduction in low back pain after 12 weeks of training compared with REG (mean difference of 3.5 points, p < 0.0001). We also observed increased endurance of trunk extensors (p = 0.002) and right (p = 0.001) and left lateral muscles (p = 0.001) in the PG compared with REG. However, the indexes of disability did not change between groups.

CONCLUSION

Pain intensity was significantly reduced while spine muscle endurance increased in PG compared with REG after intervention; thus, Pilates-based exercises should be considered in physical conditioning programs for helicopter pilots.

Five-Year Longitudinal Follow-Up of Restorative Neurostimulation Shows Durability of Effectiveness in Patients With Refractory Chronic Low Back Pain Associated With Multifidus Muscle Dysfunction

BACKGROUND

Adults with refractory, mechanical chronic low back pain associated with impaired neuromuscular control of the lumbar multifidus muscle have few treatment options that provide long-term clinical benefit. This study hypothesized that restorative neurostimulation, a rehabilitative treatment that activates the lumbar multifidus muscles to overcome underlying dysfunction, is safe and provides relevant and durable clinical benefit to patients with this specific etiology.

MATERIALS AND METHODS

In this prospective five-year longitudinal follow-up of the ReActiv8-B pivotal trial, participants (N = 204) had activity-limiting, moderate-to-severe, refractory, mechanical chronic low back pain, a positive prone instability test result indicating impaired multifidus muscle control, and no indications for spine surgery. Low back pain intensity (10-cm visual analog scale [VAS]), disability (Oswestry Disability Index), and quality of life (EuroQol's "EQ-5D-5L" index) were compared with baseline and following the intent-to-treat principle, with a supporting mixed-effects model for repeated measures that accounted for missing data.

RESULTS

At five years (n = 126), low back pain VAS had improved from 7.3 to 2.4 cm (-4.9; 95% CI, -5.3 to -4.5 cm; p < 0.0001), and 71.8% of participants had a reduction of ≥50%. The Oswestry Disability Index improved from 39.1 to 16.5 (-22.7; 95% CI, -25.4 to -20.8; p < 0.0001), and 61.1% of participants had reduction of ≥20 points. The EQ-5D-5L index improved from 0.585 to 0.807 (0.231; 95% CI, 0.195-0.267; p < 0.0001). Although the mixed-effects model attenuated completed-case results, conclusions and statistical significance were maintained. Of 52 subjects who were on opioids at baseline and had a five-year visit, 46% discontinued, and 23% decreased intake. The safety profile compared favorably with neurostimulator treatments for other types of back pain. No lead migrations were observed.

CONCLUSION

Over a five-year period, restorative neurostimulation provided clinically substantial and durable benefits with a favorable safety profile in patients with refractory chronic low back pain associated with multifidus muscle dysfunction.

CLINICAL TRIAL REGISTRATION

The Clinicaltrials.gov registration number for the study is NCT02577354; registration date: October 15, 2016; principal investigator: Christopher Gilligan, MD, Brigham and Women's Hospital, Boston, MA, USA. The study was conducted in Australia (Broadmeadow, New South Wales; Noosa Heads, Queensland; Welland, South Australia; Clayton, Victoria), Belgium (Sint-Niklaas; Wilrijk), The Netherlands (Rotterdam), UK (Leeds, London, Middlesbrough), and USA (La Jolla, CA; Santa Monica, CA; Aurora, CO; Carmel, IN; Indianapolis, IN; Kansas City, KS; Boston, MA; Royal Oak, MI; Durham, NC; Winston-Salem, NC; Cleveland, OH; Providence, RI; Spartanburg, SC; Spokane, WA; Charleston, WV).

Vibration-Induced Alteration in Trunk Extensor Muscle Proprioception as a Model for Impaired Trunk Control in Low Back Pain

This study examined the impact of personalizing muscle vibration parameters on trunk control. We assessed how altered trunk extensor muscle (TEM) proprioception affects seated trunk control in healthy controls (HCs). To explore the link between altered TEM proprioception and impaired trunk control in chronic low back pain (cLBP), we performed equivalence testing between HCs undergoing TEM vibration and cLBP without vibration. Twenty HCs performed active joint reposition error (AJRE) testing to determine personalized vibration parameters. Each participant maintained balance on an unstable chair with eyes open and closed, with and without TEM vibration. We compared trunk control between HCs and twenty age- and sex-matched cLBP participants, using mean velocity and 95% confidence ellipse area of center-of-pressure changes to quantify trunk postural control. Equivalence was examined by comparing mean difference scores to minimal detectable change values and calculating between-group effect sizes. Personalized vibration parameters led to larger lumbopelvic repositioning errors (d = 0.89) than any single vibration frequency (d = 0.31-0.36). In healthy adults with no back pain, vision had large effects on postural control (ηp2 = 0.604-0.842), but TEM vibration had no significant effects (p > 0.105) or interactions with vision (p > 0.423). Between-group effect sizes (d = 0.32-0.51) exceeded our threshold for performance equivalence (d < 0.2). Muscle vibration altered position sense during AJRE testing, and personalizing parameters amplified this effect. However, TEM vibration had minimal impact on seated trunk postural control in adults with no back pain and did not lead to performance degradation comparable to that in cLBP.

Chronic Low Back Pain: History, Symptoms, Pain Mechanisms, and Treatment

Chronic low back pain (cLBP) is the most frequently reported cause of years lived with disability. Identifying the anatomical structures or dysfunction contributing to patients' symptoms is critical to guiding treatment. The etiology of back pain and differential diagnosis is often broad, ranging from non-degenerative cLBP (trauma, tumor, inflammation, infection, etc.) to degenerative (also described as nonspecific) cLBP. After eliminating suspicion for more insidious causes of cLBP, a thorough investigation can be conducted in an attempt to identify a source of degenerative cLBP. Degenerative cLBP can originate from many sources, and a detailed understanding of the structures potentially involved is invaluable for an accurate diagnosis. This review article aims to provide a broad overview of the utility of clinical history, physical exam findings, imaging findings, and diagnostic procedures in identifying the cause of patients' cLBP. We provide a framework to help guide clinicians by dividing the structures into groups as follows: anterior vertebral column, posterior vertebral column, and extra-vertebral pain. For each condition listed, we touch on the treatment options that can be considered.

Prediction of Subsequent Vertebral Fracture After Acute Osteoporotic Fractures from Clinical and Paraspinal Muscle Features

To construct a nomogram based on clinical factors and paraspinal muscle features to predict vertebral fractures occurring after acute osteoporotic vertebral compression fracture (OVCF). We retrospectively enrolled 307 patients with acute OVCF between January 2013 and August 2022, and performed magnetic resonance imaging of the L3/4 and L4/5 intervertebral discs (IVDs) to estimate the cross-sectional area (CSA) and degree of fatty infiltration (FI) of the paraspinal muscles. We also collected clinical and radiographic data. We used univariable and multivariable Cox proportional hazards models to identify factors that should be included in the predictive nomogram. Post-OVCF vertebral fracture occurred within 3, 12, and 24 months in 33, 69, and 98 out of the 307 patients (10.8%, 22.5%, and 31.9%, respectively). Multivariate analysis revealed that this event was associated with percutaneous vertebroplasty treatment, higher FI at the L3/4 IVD levels of the psoas muscle, and lower relative CSA of functional muscle at the L4/5 IVD levels of the multifidus muscle. Area under the curve values for subsequent vertebral fracture at 3, 12, and 24 months were 0.711, 0.724, and 0.737, respectively, indicating remarkable accuracy of the nomogram. We developed a model for predicting post-OVCF vertebral fracture from diagnostic information about prescribed treatment, FI at the L3/4 IVD levels of the psoas muscle, and relative CSA of functional muscle at the L4/5 IVD levels of the multifidus muscle. This model could facilitate personalized predictions and preventive strategies.

The Role of Orthoses in Chronic Axial Spinal Conditions

PURPOSE OF REVIEW

Bracing represents a prevalent conservative, non-surgical approach used in the management of chronic spinal conditions such as spondylosis, degenerative disc disease, and spondylolisthesis. A wide variety of orthoses are available to aid in addressing cervical, thoracic, lumbar, thoracic, and SI joint pain. In this review, we aim to comprehensively examine brace types with their current applications and implications of usage.

RECENT FINDINGS

There are multiple cervical bracing options, such as soft and rigid collars, to assist in managing acute trauma and chronic degenerative conditions. The review highlights the nuanced decision-making process between hard and soft collars based on the severity of bone or ligamentous injury and neurological findings. Orthoses for low back pain are commonly used. The review highlights the challenges of chronic neck and lower back pain, emphasizing the importance of clinicians exploring all treatment strategies including braces which can improve function and reduce pain.

The automatic activity of abdominal muscles during stable and unstable standing postural tasks in older adults with and without low back pain- A cross-sectional study

BACKGROUND

The postural control and abdominal muscles' automatic activity were found to be impaired in subjects with low back pain (LBP) during static activities. However, the studies are predominantly conducted on younger adults and a limited number of studies have evaluated abdominal muscles' automatic activity during dynamic standing activities in subjects with LBP. The present study investigated the automatic activity of abdominal muscles during stable and unstable standing postural tasks in older adults with and without LBP.

METHODS

Twenty subjects with and 20 subjects without LBP were included. The thickness of the transversus abdominis (TrA), internal oblique (IO), and external oblique (EO) muscles was measured during rest (in supine), static, and dynamic standing postural tasks. To estimate automatic muscle activity, each muscle's thickness during a standing task was normalized to its thickness during the rest. Standing postural tasks were performed using the Biodex Balance System.

RESULTS

The mixed-model analysis of variance revealed that task dynamicity significantly affected thickness change only in the TrA muscle (P = 0.02), but the main effect for the group and the interaction were not significantly different (P > 0.05). There were no significant main effects of the group, task dynamicity, or their interaction for the IO and EO muscles (P > 0.05). During dynamic standing, only the TrA muscle in the control group showed greater thickness changes than during the static standing task (P < 0.05).

CONCLUSIONS

Standing on a dynamic level increased the automatic activity of the TrA muscle in participants without LBP compared to standing on a static level. Further research is required to investigate the effects of TrA muscle training during standing on dynamic surfaces for the treatment of older adults with LBP.

Healthcare resource utilization for chronic low back pain among high-utilizers

BACKGROUND

Chronic low back pain is a leading cause of morbidity and is among the largest cost drivers for the healthcare system. Research on healthcare resource utilization of patients with low back pain who are not surgical candidates is limited, and few studies follow individuals who generate high healthcare costs over time.

PURPOSE

This claims study aimed to identify patients with high-impact mechanical, chronic low back pain (CLBP), quantify their low back pain-related health resource utilization, and explore associated patient characteristics. We hypothesize that patients in the top quartile of healthcare resource utilization in the second year after initial diagnosis will continue to generate considerable back pain-related costs in subsequent years.

STUDY DESIGN/SETTING

IBM MarketScan Research Databases from 2009-2019 were retrospectively analyzed.

PATIENT SAMPLE

Adults in the United States with an initial diagnosis of low back pain between 2010 and 2014 who did not have cancer, spine surgery, recent pregnancy, or inflammatory spine conditions, were identified using the International Classification of Diseases (ICD) and Current Procedural Terminology (CPT) codes. To ensure patients had chronic low back pain, it was required that individuals had additional claims with a low back pain diagnosis 6 to 12 and 12 to 24 months after initial diagnosis.

OUTCOME MEASURES

Cost and utilization of inpatient visits, outpatient visits, emergency room visits, pharmacologic and nonpharmacologic treatment options and imaging for chronic low back pain.

METHODS

Annual back pain-related costs and the use of pharmacologic and nonpharmacologic treatments for 5 years were analyzed. Logistic regression was utilized to identify factors associated with persistent high spending.

RESULTS

Of 16,917 individuals who met the criteria for chronic low back pain, 4,229 met the criteria for having high healthcare utilization, defined as being in the top quartile of back pain-related costs in the 12 to 24 months after their initial diagnosis. The mean and median back pain-related cost in the first year after an initial diagnosis was $7,112 (SD $9,670) and $4,405 (Q1 $2,147, Q3 $8,461). Mean and median back pain related costs in the second year were $11,989 (SD $20,316) and $5,935 (Q1 $3,892, Q3 $10,678). Costs continued to be incurred in years 3 to 5 at a reduced rate. The cumulative mean cost for back pain over the 5 years following the initial diagnosis was $31,459 (SD $39,545). The majority of costs were from outpatient services. Almost a quarter of the high utilizers remained in the top quartile of back pain-related costs during years 3 to 5 after the initial diagnosis, and another 19% remained in the top quartile for 2 of the 3 subsequent years. For these two groups combined (42%), the 5-year cumulative mean cost for back pain was $43,818 (SD $48,270). Patient characteristics associated with a higher likelihood of remaining as high utilizers were diabetes, having a greater number of outpatient visits and pharmacologic prescriptions, and lower utilization of imaging services.

CONCLUSION

This is one of the first studies to use an administrative claims database to identify high healthcare resource utilizers among a population of United States individuals with nonsurgical, chronic low back pain and follow their utilization over time. There was a population of individuals who continued to experience high costs 5 years beyond their initial diagnosis, and the majority of individuals continued to seek outpatient services. Further longitudinal claims research that incorporates symptom severity is needed to understand the economic implications of this condition.

Effects of Movement Retraining and Lumbar Stabilization Exercises in Mechanical Low Back Pain: A Pilot Study

Objective To determine and compare the effects of movement retraining (MR), lumbar stabilization exercises (LSE), and a combination of both these exercises on pain, flexibility, strength, and functional disability in chronic mechanical low back pain (CMLBP) patients. Materials and methods Fifteen CMLBP participants, aged 20-40 years, were randomly allocated into three groups. Group A (n=5) received MR, group B (n=5), LSE, and group C (n=5), a combination of MR and CSE, along with hot packs for eight weeks, thrice a week on alternate days. Outcomes used were the Numerical Pain Rating Scale (NPRS), Modified Modified Schober's Test (MMST), Pressure Biofeedback (PBU), Roland Morris Disability Questionnaire (RMDQ), and Movement Control (MC) dissociation tests to identify MC impairments and were assessed at pre-intervention, post-four weeks, and post-eight weeks. The data were analyzed using repeated measures ANOVA. The level of significance was considered at p-value<0.05. Results Participants with CMLBP significantly improved in all variables in all three groups (p-value≤0.05). On inter-group comparison, group A showed better improvement in lumbar extension range of motion than the other two groups, with a mean difference of MMST in group A of 0.62±0.30, group B of 0.52±0.22, and group C of 0.36±0.02, with a p-value ≤0.002. Group C showed more improvement in core strength, with a mean difference of 5.0±0.25 in group A, 3.2±0.56 in group B, and 5.2±0.57 in group C, with a p-value ≤0.03. A significant improvement was observed in NPRS, MMST flexion, RMDQ, and uncontrolled movements (UCMs). Conclusion All three methods of treatment are effective in the management of CMLBP. Clinically, kinetic control showed better improvement in reducing pain and improving lumbar flexion and extension range of motion. Functional disability was better improved with lumbar stabilization exercises, and core strength was improved with a combination of KC and LSE. However, a combination of MR and LSE helps improve core strength, and movement retraining improves lumbar extension.

BackMov: Individualized Motion Capture-Based Test to Assess Low Back Pain Mobility Recovery after Treatment

Low back pain (LBP) is a common issue that negatively affects a person's quality of life and imposes substantial healthcare expenses. In this study, we introduce the (Back-pain Movement) BackMov test, using inertial motion capture (MoCap) to assess lumbar movement changes in LBP patients. The test includes flexion-extension, rotation, and lateralization movements focused on the lumbar spine. To validate its reproducibility, we conducted a test-retest involving 37 healthy volunteers, yielding results to build a minimal detectable change (MDC) graph map that would allow us to see if changes in certain variables of LBP patients are significant in relation to their recovery. Subsequently, we evaluated its applicability by having 30 LBP patients perform the movement's test before and after treatment (15 received deep oscillation therapy; 15 underwent conventional therapy) and compared the outcomes with a specialist's evaluations. The test-retest results demonstrated high reproducibility, especially in variables such as range of motion, flexion and extension ranges, as well as velocities of lumbar movements, which stand as the more important variables that are correlated with LBP disability, thus changes in them may be important for patient recovery. Among the 30 patients, the specialist's evaluations were confirmed using a low-back-specific Short Form (SF)-36 Physical Functioning scale, and agreement was observed, in which all patients improved their well-being after both treatments. The results from the specialist analysis coincided with changes exceeding MDC values in the expected variables. In conclusion, the BackMov test offers sensitive variables for tracking mobility recovery from LBP, enabling objective assessments of improvement. This test has the potential to enhance decision-making and personalized patient monitoring in LBP management.

Core stabilisation exercises reduce chronic low back pain in Air Force fighter pilots: a randomised controlled trial

BACKGROUND

There is evidence that core stabilisation, strength and endurance training contribute to reduce low back pain in the general population. However, we are not aware of the effect of these exercises on fighter aviation pilots. Therefore, the present study aims to investigate the effects of an exercise protocol on chronic low back pain in Brazilian Air Force fighter pilots. Changes in neck pain, lumbar disability, range of motion, strength and resistance were also investigated.

METHODS

Fourteen participants with chronic low back pain were randomised into two groups: stabilisation exercise group (SEG-n=7), exercise protocol twice a week for 12 weeks) and the regular exercise group (REG-n=7), which performed their own usual exercise routine. The evaluations were carried out before and after the training period. The primary outcome was the intensity of low back pain and the secondary outcomes were cervical pain, functional disability, range of motion, maximum isometric strength and trunk muscle resistance.

RESULTS

The SEG had a significant reduction in low back pain compared with the REG (difference of 2.3 points, p=0.04) and a lower rate of cervical pain (difference of 2.5 points, p=0.01) at the end of the protocol. Maintenance of trunk muscle strength was also observed in the SEG over the period, while the REG presented a decrease in flexural strength to the right side (difference between groups: -3.7%, p=0.04). There were no differences in the rates of disability, range of motion or resistance to fatigue between groups.

CONCLUSIONS

The stabilisation exercise programme focused on the core muscles was successful in decreasing the fighter pilots' chronic lumbar pain. Pilots are normally active; however, our results indicate that specific trunk training programmes should be offered considering the work needs of these subjects.

CLINICAL TRIALS

'Exercise protocol for pilots with back pain' (registered: 09 October 2018)-NCT03713814 (https://clinicaltrials.gov/ct2/show/NCT03713814).

Neuromuscular responses to combined neuromuscular electrical stimulation and motor control exercises in a patient with recurrent low back pain: A single subject research report

BACKGROUND

Previous studies have demonstrated changes in lumbar multifidus muscle (LM) contractility after motor control exercises (MCE), and it has been hypothesized that adding neuromuscular electrical stimulation (NMES) may help to re-activate motor units.

OBJECTIVE

To present the effects of combined NMES and MCE on LM contractility, spatial and temporal motor unit recruitment, and movement control in a patient with recurrent low back pain (rLBP).

METHODS

Motion tracking system was used to measure quality of movement (smoothness) during an active forward bend, while ultrasound imaging and decomposition electromyography were used to measure the LM contractility and motor unit recruitment during the Sorensen test. These data were collected pre and post intervention. Perceived improvement was also recorded.

RESULTS

Improved movement smoothness post intervention was found, with increases in LM contractility from 68.1% to 97.7%, and from 74.2% to 86.7% on the right and left sides, respectively. Number of motor unit increased from 14 to 18 units, while mean firing rate decreased from 10.9 to 7.1 pulses/second post intervention. The patient also reported a perceived improvement of +2 on the Global Rating of Change (GROC). However, this change was not greater than +3 to be considered as minimal clinically important difference.

CONCLUSION

These findings indicate improvements in movement control, LM contractility, and changes in spatial and temporal motor unit recruitment in the study patient, suggesting the potential clinical utility and the need for further research on combined NMES and MCE in the treatment of patients with rLBP.

What do we mean by 'self-management' for chronic low back pain? A narrative review

BACKGROUND

Chronic low back pain (CLBP) is a highly prevalent musculoskeletal condition affecting 60-80% of the general population within their lifetime. Given the large numbers of people affected, self-management approaches have been introduced as a way to manage this condition with endorsement by the national institute for health and care excellence. Interventions are often termed self-management without defining either content or goals. Our study sought to determine the content, characteristics, and evidence for self-management of CLBP.

METHODS

This narrative review was conducted using a systematic approach to search journal articles in English that focused on CLBP self-management. MEDLINE, EMBASE, CINAHL, and PsycINFO databases were used to identify publications with terms relating to back pain and self-management from January 2016 until January 2022.

RESULTS

In total, 15 studies were found suitable for inclusion in the review. Core components of self-management strategies include exercise, education, and psychological interventions, but there was a lack of consistency with respect to content. Intervention characteristics were either under-reported or varied. Furthermore, outcome measures used to assess these self-management programmes were diverse, mainly focusing on functional disability and pain intensity.

CONCLUSIONS

Inconsistencies in the content of self-management interventions, intervention characteristics, and outcome measures used for assessing self-management programmes were found across the literature. Current self-management approaches do not consider the complex biopsychosocial nature of CLBP. A consensus on the key components of self-management interventions, and how they should be evaluated, will pave the way for research to determine whether self-management can effectively manage CLBP.

Multifidus dysfunction and restorative neurostimulation: a scoping review

OBJECTIVE

Chronic low back pain (CLBP) is multifactorial in nature, with recent research highlighting the role of multifidus dysfunction in a subset of nonspecific CLBP. This review aimed to provide a foundational reference that elucidates the pathophysiological cascade of multifidus dysfunction, how it contrasts with other CLBP etiologies and the role of restorative neurostimulation.

METHODS

A scoping review of the literature.

RESULTS

In total, 194 articles were included, and findings were presented to highlight emerging principles related to multifidus dysfunction and restorative neurostimulation. Multifidus dysfunction is diagnosed by a history of mechanical, axial, nociceptive CLBP and exam demonstrating functional lumbar instability, which differs from other structural etiologies. Diagnostic images may be used to grade multifidus atrophy and assess other structural pathologies. While various treatments exist for CLBP, restorative neurostimulation distinguishes itself from traditional neurostimulation in a way that treats a different etiology, targets a different anatomical site, and has a distinctive mechanism of action.

CONCLUSIONS

Multifidus dysfunction has been proposed to result from loss of neuromuscular control, which may manifest clinically as muscle inhibition resulting in altered movement patterns. Over time, this cycle may result in potential atrophy, degeneration and CLBP. Restorative neurostimulation, a novel implantable neurostimulator system, stimulates the efferent lumbar medial branch nerve to elicit repetitive multifidus contractions. This intervention aims to interrupt the cycle of dysfunction and normalize multifidus activity incrementally, potentially restoring neuromuscular control. Restorative neurostimulation has been shown to reduce pain and disability in CLBP, improve quality of life and reduce health care expenditures.

PILLAR: ParaspInaL muscLe segmentAtion pRoject - a comprehensive online resource to guide manual segmentation of paraspinal muscles from magnetic resonance imaging

BACKGROUND

There is an increasing interest in assessing paraspinal morphology and composition in relation to low back pain (LBP). However, variations in methods and segmentation protocols contribute to the inconsistent findings in the literature. We present an on-line resource, the ParaspInaL muscLe segmentAtion pRoject (PILLAR, https://projectpillar.github.io/ ), to provide a detailed description and visual guide of a segmentation protocol by using the publicly available ITK-SNAP software and discuss related challenges when performing paraspinal lumbar muscles segmentations from magnetic resonance imaging (MRI).

METHODS

T2-weighted and corresponding fat-water IDEAL axial MRI from 3 males and 3 females (2 chronic LBP and 1 control for each sex) were used to demonstrate our segmentation protocol for each lumbar paraspinal muscle (erector spinae, lumbar multifidus, quadratus lumborum and psoas) and lumbar spinal level (L1-L5).

RESULTS

Proper segmentation requires an understanding of the anatomy of paraspinal lumbar muscles and the variations in paraspinal muscle morphology and composition due to age, sex, and the presence of LBP or related spinal pathologies. Other challenges in segmentation includes the presence and variations of intramuscular and epimuscular fat, and side-to-side asymmetry.

CONCLUSION

The growing interest to assess the lumbar musculature and its role in the development and recurrence of LBP prompted the need for comprehensive and easy-to-follow resources, such as the PILLAR project to reduce inconsistencies in segmentation protocols. Standardizing manual muscle measurements from MRI will facilitate comparisons between studies while the field is progressively moving towards the automatization of paraspinal muscle measurements for large cohort studies.

Hatha yoga is more effective in improving kinesiophobia and subjective well-being when combined with self-compassion meditation in people with CLBP: a randomized control trial

Objective

The present study aims to examine whether combining hatha yoga practice with self-compassion meditation could influence kinesiophobia, emotions, perceived stress, and perceived disability among individuals with chronic low back pain when compared with hatha yoga alone.

Methods

The randomized controlled study included 70 participants with chronic low back pain (CLBP) who were randomly assigned to a Hatha yoga group (HY; n = 35) or a Hatha yoga group plus self-compassion meditation (HYSCM; n = 35). Participants followed a protocol for 8 weeks, and the assessments were carried out before and after the intervention, with a follow-up evaluation conducted after one month. The participants completed the PANAS, PSS, TSK, and RMQ questionnaires. A Generalized Estimating Equation was used to explore the effect of interventions.

Results

Both HY and HYSCM groups improved kinesiophobia, perceived disability, and stress at the follow-up. However, the HYSCM group shown a more significant reduction in kinesiophobia compared to the HY group. Moreover, significant improvement in positive affect and a reduction in negative affect over time in the HYSCM group were observed.

Conclusion

Hatha yoga practice when combined with self-compassion meditation led to extra benefits by exhibiting a prolonged effect, especially on kinesiophobia positive and negative effects.

Functional Alterations of the Basal Ganglia Are Associated with Voluntary Activation of the Core Stabilizing Muscles in Patients with Chronic Low Back Pain: A Cross-Sectional Study

Purpose

Deficits in voluntary activation of the core stabilizing muscles are consistently observed in patients with chronic low back pain (CLBP); however, the underlying neural mechanism remains unclear. This cross-sectional study aimed at testing the hypothesis that the impaired voluntary activation of core stabilizing muscles is associated with structural and functional alterations in the basal ganglia, thalamus, and cortex in patients with CLBP.

Methods

We obtained structural and resting-state functional magnetic resonance imaging (rs-fMRI) data from 53 patients with CLBP and 67 healthy controls and estimated the alterations in grey matter volume (GMV) and functional and effective connectivity (EC) of regions with altered GMV via whole brain analysis. The voluntary activation of the multifidus (MF) and transversus abdominis (TrA) was evaluated by ultrasound imaging in these patients.

Results

Compared with the HCs, they displayed a significant decrease in GMV in the bilateral thalamus and caudate nucleus, a significant increase in GMV in the left middle frontal gyrus, and increased resting-state functional connectivity between the right caudate nucleus and the bilateral precuneus (voxel-level p < 0.005, Gaussian random field-corrected p < 0.05). The patients also showed increased EC from the right caudate nucleus to the bilateral precuneus, which was significantly correlated with voluntary activation of the bilateral MF and TrA (all p < 0.050).

Conclusions

Grey matter alterations may be confined to regions responsible for perception, motor control, and emotion regulation in patients with CLBP. The interrupted EC from the basal ganglia to the default mode network might be involved in the impairment of voluntary activation of the core stabilizing muscles.

Risk factors analysis and risk prediction model construction of non-specific low back pain: an ambidirectional cohort study

PURPOSE

Non-specific low back pain (NLBP) is a common clinical condition that affects approximately 60-80% of adults worldwide. However, there is currently a lack of scientific prediction and evaluation systems in clinical practice. The purpose of this study was to analyze the risk factors of NLBP and construct a risk prediction model.

METHODS

We collected baseline data from 707 patients who met the inclusion criteria and were treated at the Sixth Hospital of Ningbo from December 2020 to December 2022. Logistic regression and LASSO regression were used to screen independent risk factors that influence the onset of NLBP and to construct a risk prediction model. The sensitivity and specificity of the model were evaluated by tenfold cross-validation, and internal validation was performed in the validation set.

RESULTS

Age, gender, BMI, education level, marital status, exercise frequency, history of low back pain, labor intensity, working posture, exposure to vibration sources, and psychological status were found to be significantly associated with the onset of NLBP. Using these 11 predictive factors, a nomogram was constructed, and the area under the ROC curve of the training set was 0.835 (95% CI 0.756-0.914), with a sensitivity of 0.771 and a specificity of 0.800. The area under the ROC curve of the validation set was 0.762 (95% CI 0.665-0.858), with a sensitivity of 0.800 and a specificity of 0.600, indicating that the predictive value of the model for the diagnosis of NLBP was high. In addition, the calibration curve showed a high degree of consistency between the predicted and actual survival probabilities.

CONCLUSION

We have developed a preliminary predictive model for NLBP and constructed a nomogram to predict the onset of NLBP. The model demonstrated good performance and may be useful for the prevention and treatment of NLBP in clinical practice.

Application of hot medicated fomentation for pain alleviation in non-specific low back pain - A randomized controlled clinical trial

BACKGROUND

Non-specific low back pain is a leading contributor to disease burden and works absenteeism worldwide with a lifetime prevalence of 60-70% in industrialized countries. This clinical study aimed to assess the efficacy of hot fomentation with half-baked medicated bread (khubz) compared to hot water bag fomentation to alleviate pain and disability in non-specific low back pain.

METHODS

In this randomized-controlled study, fifty-four patients with low back pain were randomly assigned into two groups to receive either hot fomentation (Takmīd-e-haar) with half-baked medicated bread in the test group or hot water bag fomentation in the control group, on the lumbosacral region daily for 30 min for 15 consecutive days. Patients were assessed statistically using the visual analogue scale (VAS) and Oswestry disability index (ODI) at baseline, 7th and after treatment (15th day).

RESULTS

After the intervention, statistically significant improvements (p < 0.001) were observed in VAS and ODI scores in both the groups on the intragroup comparison. The test treatment showed better efficacy in comparison to the control treatment with a mean difference of 1.75 in VAS (p < 0.0001) and 8.20 in ODI (p = 0.001).

CONCLUSION

The tested intervention showed significantly better efficacy in comparison to the hot water bag fomentation probably due to the analgesic (musakkin-i-alam), anti-inflammatory (muḥallil-i-awrām), and demulcent (mulaṭṭif) properties of the ingredients of tested Unani formulation in addition to the effects of heat. It may therefore be concluded that medicated fomentation is an effective, safer, feasible, and less expensive regimen for patients with non-specific low back pain.

TRIAL REGISTRATION

The Clinical Trials Registry-India (CTRI/2020/03/024107).

Efficacy and safety of extracorporeal shockwave therapy in chronic low back pain: a systematic review and meta-analysis of 632 patients

BACKGROUND

Extracorporeal shock wave therapy (ESWT) has been widely used for pain control in musculoskeletal disorders. Whether ESWT can relieve chronic low back pain (CLBP) and improve lumbar function is still unclear. Therefore, we conducted a meta-analysis of relevant studies to comprehensively analyse and determine the efficacy and safety of ESWT for chronic low back pain.

METHODS

Four databases were systematically searched for randomized controlled trials (RCTs) on ESWT for CLBP. The quality of the included studies was evaluated according to Cochrane systematic review criteria, relevant data were extracted, and meta-analysis was performed using RevMan 5.4 software. The primary outcomes were pain intensity, disability status, and mental health. The data were expressed as standardized mean differences (SMD) or weighted mean difference (WMD) and 95% confidence intervals (CI). Heterogeneity was assessed using the I² statistic. If I² ≥ 50%, a random effects model was applied; otherwise, a fixed effects model was used.

RESULTS

Twelve RCTs involving 632 patients were included in this meta-analysis. The ESWT group reported significantly more pain relief than the control group at 4 weeks (WMD =  - 1.04; 95% CI =  - 1.44 to - 0.65; P < 0.001) and 12 weeks (WMD =  - 0.85; 95% CI =  - 1.30 to - 0.41; P < 0.001). Regarding the dysfunction index, ESWT led to significant improvement in lumbar dysfunction compared with the control group at 4 weeks (WMD =  - 4.22; 95% CI =  - 7.55 to - 0.89; P < 0.001) and 12 weeks (WMD =  - 4.51; 95% CI =  - 8.58 to - 0.44; P = 0.03). For mental health, there was no significant difference between the ESWT group and the control group after 4 weeks of intervention (SMD = 1.17; 95% CI =  - 0.10 to 2.45; P = 0.07).

CONCLUSION

This systematic review and meta-analysis found that ESWT provided better pain relief and improved lumbar dysfunction compared with the other interventions included, and no serious adverse effects were found. There was no significant effect of ESWT on the mental health of patients, but we hope to obtain more RCTs for further analysis in the future. Based on the pooled results, we suggest that ESWT is effective and safe for treating chronic low back pain.

Between guidelines and clinical trials: evidence-based advice on the pharmacological management of non-specific chronic low back pain

The pharmacological management of nonspecific chronic low back pain (NCLBP) aims to restore patients' daily activities and improve their quality of life. The management of NCLBP is not well codified and extremely heterogeneous, and residual symptoms are common. Pharmacological management should be considered as co-adjuvant to non-pharmacological therapy, and should be guided by the symptoms reported by the patients. Depending on the individual severity of NCLPB, pharmacological management may range from nonopioid to opioid analgesics. It is important to identify patients with generalized sensory hypersensitivity, who may benefit from dedicated therapy. This article provides an evidence-based overview of the principles of pharmacological management of NCLPB.

Changes in psoas and posterior paraspinal muscle morphology after standalone lateral lumbar interbody fusion: a quantitative MRI-based analysis

PURPOSE

Standalone lateral lumbar interbody fusion (SA-LLIF) without posterior instrumentation can be an alternative to 360° fusion in selected cases. This study aimed to investigate quantitative changes in psoas and paraspinal muscle morphology that occur on index levels after SA-LLIF.

METHODS

Patients undergoing single- or multi-level SA-LLIF at L2/3 to L4/5 who had preoperative and postoperative lumbar MRI scans, the latter performed between 3 and 18 months after surgery for any reason, were retrospectively included. Muscle measurements were performed of the psoas and posterior paraspinal muscles (PPM; erector spinae and multifidus) on index levels using manual segmentation and an automated pixel intensity threshold method to differentiate muscle from fat signal. Changes in the total cross-sectional area (TCSA), the functional cross-sectional area (FCSA), and the percentage of fat infiltration (FI) of these muscles were assessed.

RESULTS

A total of 67 patients (55.2% female, age 64.3 ± 10.6 years, BMI 26.9 ± 5.0 kg/m2) with 125 operated levels were included. Follow-up MRI scans were performed after an average of 8.7 ± 4.6 months, primarily for low back pain. Psoas muscle parameters did not change significantly, irrespective of the approach side. Among PPM parameters, the mean TCSA at L4/5 (+ 4.8 ± 12.4%; p = 0.013), and mean FI at L3/4 (+ 3.1 ± 6.5%; p = 0.002) and L4/5 (+ 3.0 ± 7.0%; p = 0.002) significantly increased.

CONCLUSION

Our study demonstrated that SA-LLIF did not alter psoas muscle morphology, underlining its minimally invasive nature. However, FI of PPM significantly increased over time despite the lack of direct tissue damage to posterior structures, suggesting a pain-mediated response and/or the result of segmental immobilization.

A standardized anesthetic/analgetic regimen compared to standard anesthetic/analgetic regimen for patients with high-risk factors undergoing open lumbar spine surgery: a prospective comparative single-center study

The objective of the study is to improve the results of patients undergoing lumbar spine surgery who are at high risk for anesthesia and/or surgical complications. Two independent groups were compared: the study group (SG, n = 40) (standardized neuroanesthetic protocol with multimodal analgesia) and the control group (CG, n = 40) (intravenous anesthesia based on propofol and fentanyl). The data were collected using prospective observation of early and long-term results of lumbar fusion. After 24 months, the level of functional state and quality of life were studied. Patients in the SG did not have statistically significant changes in intraoperative hemodynamics; the best indicators of cognitive functions were noted. The effectiveness of the SG compared with the CG was confirmed by a statistically significantly lower amount of perioperative opioid drugs required (p = 0.01) and a minimal level of incisional pain (p < 0.05). An intergroup comparison of the adverse effects of anesthesia revealed a significantly lower number in the SG (n = 4) compared to the CG (n = 16) (p = 0.004). The number of postoperative surgical complications was comparable (p = 0.72). Intergroup comparison showed improved ODI, SF-36, and the Macnab scale at 24 months after surgery in the SG compared to the CG (p < 0.05). Long-term clinical results correlated with the level of incisional pain in the first three postoperative days. Our standardized neuroanesthetic protocol ensured effective treatment of postoperative incisional pain, significantly decreased the perioperative use of opioids, reduced adverse anesthesia events, and improved long-term clinical results in patients with high risk factors for anesthetic complications who undergoing open lumbar spine surgery.

ReActiv8 Stimulation Therapy vs. Optimal Medical Management: A Randomized Controlled Trial for the Treatment of Intractable Mechanical Chronic Low Back Pain (RESTORE Trial Protocol)

INTRODUCTION

Chronic low back pain (CLBP) is the leading cause of years lived with disability globally. The role of restorative neurostimulation in the treatment of patients with refractory mechanical CLBP and multifidus muscle dysfunction has been established in one randomized controlled trial (RCT) and several clinical studies that demonstrated both safety and clinical benefit. This post-market trial provides a direct comparison to optimized medical management to test the hypothesis that the addition of restorative neurostimulation to current care paradigms results in significant improvements in back pain-related disability.

METHODS AND ANALYSIS

This trial will include people who have reported significant levels of back pain and back pain-related disability with symptoms that have persisted for longer than 6 months prior to enrollment and resulted in pain on most days in the 12 months prior to enrollment. Eligible patients will be randomized to either optimal medical management or optimal medical management plus ReActiv8® restorative neurostimulation therapy. Patient-reported outcomes will be collected at regular intervals out to the 1-year primary endpoint, at which time the patients in the control arm will be offered implantation with the ReActiv8 system. Assessment of each group will continue for an additional year.

ETHICS AND DISSEMINATION

The RESTORE trial follows the principles of the Declaration of Helsinki. The WCG IRB acts as the Central Institutional Review Board (IRB) for most sites and some sites will receive local IRB approval prior to enrollment of patients. Each IRB assessed the protocol and related documentation. The protocol complies with Good Clinical Practice (GCP). All patients provide written informed consent to participate in the trial.

PROTOCOL VERSION

Version C, 07 Sep 2022.

CLINICALTRIALS

gov registration number. NCT04803214 registered March 17, 2021.

Linear spectrum and non-linear complexity features of lumbar muscle surface electromyography between people with and without non-specific chronic low back pain during Biering-Sorensen test

PURPOSE

This study aimed to investigate the electromyographic parameters of lumbar muscles during the Biering-Sorensen test (BST) in people with and without non-specific chronic low back pain (NCLBP).

MATERIALS AND METHODS

Thirteen healthy controls and thirteen NCLBP patients participated in the current study, where they performed the 90s-BST, while the surface electromyography (sEMG) was recorded from the erector spinae (ES) at L1 and L3 level and lumbar multifidus (LM) at L5 level, bilaterally. Spectral and nonlinear analyses were applied by calculating mean power frequency (MPF), fractal dimension (FD) and the percentage of determinism (%DET) in the 10-second non-overlapping time-windows and EMG-EMG coherence during the first half and second half of the BST. Also, the slopes of the linear fitting curves of MPF, FD and %DET were calculated.

RESULTS

NCLBP group had significantly lower rates of changes in MPF, FD and %DET compared to asymptomatic controls in the ES(L3) and LM. Coherence in left-right LM and in the right ES-LM increased significantly in the gamma band in the Control group with no increase in the NCLBP group.

CONCLUSIONS

Our findings indicated that compared to people with NCLBP, the sEMG signals of lumbar muscles of people without NCLBP were more regular and less complex during the 90s-BST.

Effect of Cognitive Load on Anticipatory Postural Adjustment Latency and its Relationship with Pain-Related Dysfunction in Non-specific Chronic Low Back Pain: A Cross-Sectional Study

INTRODUCTION

This study aimed to investigate the effect of cognitive load on anticipatory postural adjustment (APA) latency in patients with non-specific chronic low back pain (NCLBP) and its relationship with pain-related functional changes.

METHODS

A cross-sectional study was conducted from December 15, 2022 to January 25, 2023. Participants were divided into a healthy control group (n = 29) and an NCLBP group (n = 29). Each group was assigned a single task of rapid arm raising and a dual task of rapid arm raising combined with a cognitive load. The cognitive load task was conducted using visual conflict. The APA latency for bilateral trunk muscles was observed using electromyography. The duration of electromyography recording in each task cycle was 28 s. Pain related-functional changes were evaluated using Roland-Morris Disability Questionnaire (RMDQ) before all tasks.

RESULTS

The APA latency for the right multifidus was significantly delayed in the NCLBP group [25.38, 95% confidence interval (CI) 13.41-37.35] than in the healthy control group (- 5.80, 95% CI - 19.28 to 7.68) during dual task (p = 0.0416). The APA latency for the right multifidus (25.38, 95% CI 13.41-37.35) and transverse abdominis/internal oblique (29.15, 95% CI 18.81-39.50) were significantly delayed compared with on the left side in the NCLBP group during dual task (- 3.03, 95% CI - 15.18-9.13, p = 0.0220; 3.69, 95% CI - 6.81 to 14.18, p = 0.0363). The latency delay of the right and left multifidus APA in the NCLBP group under the dual-task was positively correlated with RMDQ scores (r = 0.5560, p = 0.0017; r = 0.4010, p = 0.0311).

CONCLUSIONS

Cognitive load could induce APA delay in the right trunk muscles and co-activation pattern changes in bilateral trunk muscle APA in patients with NCLBP. The APA onset delay in multifidus is positively related to pain-related daily dysfunction. Trial Registration ChiCTR2300068580 (retrospectively registered in February 23, 2023).

Effect of Progressive Postural Control Exercise Versus Core Stability Exercise in Young Adults with Chronic Low Back Pain: A Randomized Controlled Trial

INTRODUCTION

This study aimed to investigate the effects of progressive postural control exercise (PPCE) vs core stability exercise (CSE) in patients with chronic low back pain (CLBP).

METHODS

A total of 34 young-adult participants with CLBP were randomly assigned to two groups (the PPCE group and the CSE group). They received instructions for two different exercise training regimens persisting over 8 weeks. Before, after, and at 6 months after the intervention, the participants were evaluated on the basis of pain intensity (VAS), degree of dysfunction (ODI and RMDQ), contractility of transversus abdominis (TrA) and lumbar multifidus (MF), as well as the ability to control static posture.

RESULTS

There was no significant difference between the results of the PPCE group and the CSE group. At the 6-month follow-up after the 8-week treatment, the scores of VAS, ODI, and RMDQ in the two groups decreased significantly compared to before (p < 0.05). The percentage change in thickness of bilateral TrA and left MF (p < 0.05) was elevated and the sway area of center of pressure during static stance tasks with eyes opened (p < 0.05) was decreased in both groups.

CONCLUSION

In the short term, PPCE provides positive effects similar to those of core stability exercise in patients with CLBP. The effective mechanism of PPCE might be the consequence of neuromuscular plasticity and adaptation adjustments. PPCE enriches the choices of treatment for CLBP.

CLINICAL TRIAL REGISTRATION

The trial was registered at www.chictr.org.cn , identifier ChiCTR2100043113.

Three-Year Durability of Restorative Neurostimulation Effectiveness in Patients With Chronic Low Back Pain and Multifidus Muscle Dysfunction

BACKGROUND

Restorative neurostimulation is a rehabilitative treatment for patients with refractory chronic low back pain (CLBP) associated with dysfunction of the lumbar multifidus muscle resulting in impaired neuromuscular control. The ReActiv8-B randomized, sham-controlled trial provided evidence of the effectiveness and safety of an implanted, restorative neurostimulator. The two-year analysis previously published in this journal demonstrated accrual of clinical benefits and long-term durability.

OBJECTIVE

Evaluation of three-year effectiveness and safety in patients with refractory, disabling CLBP secondary to multifidus muscle dysfunction and no indications for spine surgery.

MATERIALS AND METHODS

Prospective, observational follow-up of the 204 implanted trial participants. Low back pain visual analog scale (VAS), Oswestry Disability Index (ODI), EuroQol quality of life survey, and opioid intake were assessed at baseline, six months, and one, two, and three years after activation. The mixed-effects model repeated measures approach was used to provide implicit imputations of missing data for continuous outcomes and multiple imputation for proportion estimates.

RESULTS

Data were collected from 133 participants, and 16 patients missed their three-year follow-up because of coronavirus disease restrictions but remain available for future follow-up. A total of 62% of participants had a ≥ 70% VAS reduction, and 67% reported CLBP resolution (VAS ≤ 2.5cm); 63% had a reduction in ODI of ≥ 20 points; 83% had improvements of ≥ 50% in VAS and/or ≥ 20 points in ODI, and 56% had these substantial improvements in both VAS and ODI. A total of 71% (36/51) participants on opioids at baseline had voluntarily discontinued (49%) or reduced (22%) opioid intake. The attenuation of effectiveness in the imputed (N = 204) analyses was relatively small and did not affect the statistical significance and clinical relevance of these results. The safety profile remains favorable, and no lead migrations have been observed to date.

CONCLUSION

At three years, 83% of participants experienced clinically substantial improvements in pain, disability, or both. The results confirm the long-term effectiveness, durability, and safety of restorative neurostimulation in patients with disabling CLBP associated with multifidus muscle dysfunction.

CLINICAL TRIAL REGISTRATION

The Clinicaltrials.gov registration number for the study is NCT02577354.

Long-Term Outcomes of Restorative Neurostimulation in Patients With Refractory Chronic Low Back Pain Secondary to Multifidus Dysfunction: Two-Year Results of the ReActiv8-B Pivotal Trial

BACKGROUND

Impaired neuromuscular control and degeneration of the multifidus muscle have been linked to the development of refractory chronic low back pain (CLBP). An implantable restorative-neurostimulator system can override the underlying multifidus inhibition by eliciting episodic, isolated contractions. The ReActiv8-B randomized, active-sham-controlled trial provided effectiveness and safety evidence for this system, and all participants received therapeutic stimulation from four months onward.

OBJECTIVE

This study aimed to evaluate the two-year effectiveness of this restorative neurostimulator in patients with disabling CLBP secondary to multifidus muscle dysfunction and no indications for spine surgery.

MATERIALS AND METHODS

Open-label follow-up of 204 participants implanted with a restorative neurostimulation system (ReActiv8, Mainstay Medical, Dublin, Ireland) was performed. Pain intensity (visual analog scale [VAS]), disability (Oswestry disability index [ODI]), quality-of-life (EQ-5D-5L), and opioid intake were assessed at baseline, six months, one year, and two years after activation.

RESULTS

At two years (n = 156), the proportion of participants with ≥50% CLBP relief was 71%, and 65% reported CLBP resolution (VAS ≤ 2.5 cm); 61% had a reduction in ODI of ≥20 points, 76% had improvements of ≥50% in VAS and/or ≥20 points in ODI, and 56% had these substantial improvements in both VAS and ODI. A total of 87% of participants had continued device use during the second year for a median of 43% of the maximum duration, and 60% (34 of 57) had voluntarily discontinued (39%) or reduced (21%) opioid intake.

CONCLUSIONS

At two years, 76% of participants experienced substantial, clinically meaningful improvements in pain, disability, or both. These results provide evidence of long-term effectiveness and durability of restorative neurostimulation in patients with disabling CLBP, secondary to multifidus muscle dysfunction.

CLINICAL TRIAL REGISTRATION

The study is registered on clinicaltrials.gov with identifier NCT02577354.

Transcatheter Arterial Embolization for Alleviating Chronic Musculoskeletal Pain and Improving Physical Function: A Narrative Review

Chronic musculoskeletal pain imposes immense suffering and diminishes the quality of life for millions of patients worldwide; the pain persists despite the use of standard conservative treatments. Increases in our understanding of the pathophysiological mechanisms underlying musculoskeletal disorders indicate the involvement of inappropriate angiogenesis. Accordingly, the resulting neovessels are the target of emerging treatments for chronic musculoskeletal pain, including transarterial embolization. The use of this noninvasive procedure to treat pain refractory to standard therapy in a variety of musculoskeletal conditions is the focus of numerous recent investigations. Here, we describe the pathophysiological indications for the use of transarterial embolization and summarize the findings of studies investigating its use in a variety of histopathological conditions and anatomical sites.

Preoperative Association Between Quantitative Lumbar Muscle Parameters and Spinal Sagittal Alignment in Lumbar Fusion Patients

STUDY DESIGN

A retrospective cross-sectional study.

OBJECTIVE

To assess the association between spinal muscle morphology and spinopelvic parameters in lumbar fusion patients, with a special emphasis on lumbar lordosis (LL).

SUMMARY OF BACKGROUND DATA

Maintenance of sagittal alignment relies on muscle forces, but the basic association between spinal muscles and spinopelvic parameters is poorly understood.

MATERIALS AND METHODS

Patients operated between 2014 and 2017 who had both lumbar magnetic resonance imaging scan and standing whole-spine radiographs within six months before surgery were included. Muscle measurements were conducted on axial T2-weighted magnetic resonance images at the superior endplate L3-L5 for the psoas and L3-S1 for combined multifidus and erector spinae (paraspinal) muscles. A pixel intensity threshold method was used to calculate the total cross-sectional area (TCSA) and the functional cross-sectional area (FCSA). Spinopelvic parameters were measured on lateral standing whole-spine radiographs and included LL, pelvic incidence (PI), PI-LL mismatch, pelvic tilt, sacral slope, thoracic kyphosis, and sagittal vertical axis. Analyses were stratified by biological sex. Multivariable linear regression analyses with adjustments for age and body mass index (BMI) were performed.

RESULTS

A total of 104 patients (62.5% female) were included in the analysis. The patient population was 90.4% White with a median age at surgery of 69 years and a median BMI of 27.8 kg/m 2 . All muscle measurements were significantly smaller in women. PI, pelvic tilt, and thoracic kyphosis were significantly greater in women. PI-LL mismatch was 6.1° (10.6°) in men and 10.2° (13.5°) in women ( P =0.106), and sagittal vertical axis was 45.3 (40.8) mm in men and 35.7 (40.8) mm in women ( P =0.251). After adjusting for age and BMI, paraspinal TCSA at L3-L5, and paraspinal FCSA at L4 showed significant positive associations with LL in women. In men, psoas TCSA at L5 and psoas FCSA at L5 showed significant negative associations with LL, but none of the paraspinal muscle measurements.

CONCLUSION

Our findings indicate that psoas and lumbar spine extensor muscles interact differently on LL among men and women, creating a unique mechanical environment.

LEVEL OF EVIDENCE

Level 4.

Comparison of compensatory lumbar movement in participants with and without non-specific chronic low back pain: A cross-sectional study

BACKGROUND

Many studies have compared muscle length and muscle activity for low back pain. However, compensatory movement for non-specific low back pain has not yet been studied sufficiently.

OBJECTIVE

The purpose of this study was to compare the length of the hip flexor, lumbar extensor endurance and the muscle activity of the erector spinae and gluteus maximus during hip extension, and the compensatory movement of the lumbar in people with or without nonspecific chronic low back pain.

METHODS

In this case-control study, 16 participants with non-specific chronic LBP and 17 without LBP were included. Hip flexor length was assessed by the modified Thomas test. Lumbar extensor endurance was assessed by the modified Biering-Sorensen test. Muscle activity of the erector spinae and gluteus maximus during hip extension was measured using a Delsys-Trigno wireless EMG system. Compensatory lumbar movements during hip extension were measured using a digital inclinometer.

RESULTS

Muscle activity of the erector spinae and compensatory lumbar movements were significantly higher in the LBP group. (p< 0.05). Hip flexor length, muscle activity of the gluteus maximus and endurance of the lumbar extensor were significantly differences in the LBP group (p< 0.05).

CONCLUSIONS

Shortened hip flexors, low gluteus maximus activity, and high erector spinae activity during hip extension, lumbar extensor weak endurance, lumbar compensatory movement are potential factors for non-specific LBP.

The effect and mechanism of traditional Chinese exercise for chronic low back pain in middle-aged and elderly patients: A systematic review

Background

Increasing lines of evidence indicate that traditional Chinese exercise (TCE) has potential benefits in improving chronic low back pain (CLBP) symptoms. To assess the clinical efficacy of TCE in the treatment of CLBP, we performed a systematic review of existing randomized controlled trials (RCTs) of CLBP and summarized the neural mechanisms underlying TCE in the treatment of CLBP.

Methods

A systematic search was conducted in four electronic databases: PubMed, Embase, the Cochrane Library, and EBSCO from January 1991 to March 2022. The quality of all included RCTs was evaluated by the Physiotherapy Evidence Database Scale (PEDro). The primary outcomes included pain severity and pain-related disability.

Results

A total of 11 RCTs with 1,256 middle-aged and elderly patients with CLBP were included. The quality of all 11 included RCTs ranged from moderate to high according to PEDro. Results suggested that TCE could considerably reduce pain intensity in patients with CLBP. Overall, most studies did not find any difference in secondary outcomes (quality of life, depression, and sleep quality).

Conclusion

The neurophysiological mechanism of TCE for treating CLBP could be linked to meditation and breathing, posture control, strength and flexibility training, and regulation of pain-related brain networks. Our systematic review showed that TCE appears to be effective in alleviating pain in patients with CLBP.

Comparative effectiveness of electroacupuncture VS neuromuscular electrical stimulation in the treatment of chronic low back pain in active-duty personals: A single-center, randomized control study

Introduction

Low back pain (LBP) is the most prevalent form of chronic pain in active-duty military personnel worldwide. Electroacupuncture (EA) and neuromuscular electrical stimulation (NMES) are the two most widely used treatment methods in the military, while evidence for their benefits is lacking. The aim of this randomized clinical trial is to investigate the effectiveness of EA vs. NMES in reducing pain intensity among active-duty navy personals with chronic LBP.

Methods

The study is designed as a single-center, randomized controlled trial. The primary outcome is a positive categorical response for treatment success in the first-time follow-up, which is predesignated as a two-point or greater decrease in the NRS score and combined with a score > 3 on the treatment satisfaction scale. The secondary outcomes include pain intensity, rate of treatment success, and Oswestry Disability Index (ODI) fear-avoidance beliefs questionnaire (FABQ) score along with muscular performance. The first follow-up starts on the first day after completing the last treatment session, and then the 4-weeks and 12-weeks follow-up are applied via telephone visit.

Results

Eighty-five subjects complete the treatment diagram and are included in the analysis. For the primary outcome, no difference has been found between EA and NMES, with 65.1% (28 in 43) individuals reporting a positive response to EA treatment, while 53.5% (23 in 43) in NMES. However, for longer follow-ups, superiority in positive response of EA has been found in 4-weeks (26 in 39, 66.7% vs. 16 in 40, 40%; P = 0.018) and 12-weeks (24 in 36, 66.7% vs. 12 in 36, 33.3%; P = 0.005) follow-up. In the regression analysis, baseline pain intensity and FABQ score are identified to be highly associated with positive treatment outcomes. Finally, the subgroup analysis suggests that EA treatment is associated with better long-term outcomes in patients with LBP with a severe pain score (NRS score >4, Figure 4B) and stronger fear-avoidance beliefs.

Conclusion

Both the EA and NMES are associated with a positive response in treating military LBP, and the former offers lasting benefits in the later follow-ups. Thus, electroacupuncture is a more recommended treatment for military LBP. A lot of research is needed to verify an efficient and standardized treatment session, with more information and evidence about indications for these treatments.

Trial registration

ChiCTR, (ChiCTR2100043726); registered February 27, 2021.

The Role of Exercise in Treating Low Back Pain

ABSTRACT

The purpose of this review is to highlight the role of exercise in preventing and managing acute and chronic axial low back pain (LBP). LBP is one of the leading contributors to years lived with disability as well as health care expenditures in the United States. With an expected increase in prevalence due to an aging population, sports medicine providers have a unique opportunity to provide effective treatment strategies incorporating exercise advice and prescription. Although the majority of individuals with acute LBP will have their symptoms resolve spontaneously, almost 40% will have recurrence or develop chronic LBP within 1 year. No single exercise method has been shown to be more effective than another. The evidence for walking programs, aerobic exercise, yoga, Pilates, and tai chi for LBP is discussed. Our review summarizes the beneficial role of a personalized exercise program and related counseling strategies in the prevention and management of LBP.

Neuromuscular Consequences of Lumbopelvic Dysfunction: Research and Clinical Perspectives

Injuries involving the lumbopelvic region (ie, lumbar spine, pelvis, hip) are common across the lifespan and include pathologies such as low back pain, femoroacetabular impingement syndrome, labrum tear, and osteoarthritis. Joint injury is known to result in an arthrogenic muscle response which contributes to muscle weakness and altered movement patterns. The purpose of this manuscript is to summarize the arthrogenic muscle response that occurs across lumbopelvic region pathologies, identify methods to quantify muscle function, and propose suggestions for future research. While each lumbopelvic region pathology is unique, there are a few common impairments and a relative consistent arthrogenic muscle response that occurs across the region. Hip muscle weakness and hip joint range of motion limitations occur with both lumbar spine and hip pathologies, and individuals with low back pain are known to demonstrate inhibition of the transversus abdominis and multifidus. Assessment of muscle inhibition is often limited to research laboratory settings, but dynamometers, ultrasound imaging, and electromyography offer clinical capacity to quantify muscle function and inform treatment pathways. Future studies should systematically determine the arthrogenic muscle response across multiple muscle groups and the timeline for changes in muscle function and determine whether disinhibitory modalities improve functional outcomes beyond traditional treatment approaches.

Restorative Neurostimulation: A Clinical Guide for Therapy Adoption

In this review, we present a comprehensive clinical approach to restorative neurostimulation, a novel form of stimulation for refractory chronic mechanical low back pain, targeting impaired neuromuscular control and degeneration of the multifidus muscle. We focus on patient identification, technique guidance, and review of the scientific background and clinical evidence. As our understanding of back pain grows, there is clear evidence that impaired neuromuscular control and consequent degeneration of the multifidus muscle contribute to mechanical low back pain development and maintenance. We provide clinical guidance regarding an implantable restorative neurostimulation system that targets impaired neuromuscular control. Supported by results from a randomized, active-sham-controlled clinical trial with long-term follow-up, we provide clinicians with a comprehensive overview and practical clinical guidance for the adoption of this therapy modality.

Alterations in kinematics of temporomandibular joint associated with chronic neck pain

BACKGROUND

Temporomandibular disorder (TMD) is an umbrella term for pain and dysfunction of the temporomandibular joint (TMJ) and its associated structures. Patients with TMD show changes in TMJ kinematics and masticatory muscle activation. TMD is commonly comorbid with non-specific chronic neck pain (NCNP), which may be one of the risk factors for TMD.

OBJECTIVES

This study aimed to investigate whether patients with NCNP have altered TMJ kinematics and masticatory muscle activity.

METHODS

This was a cross-sectional exploratory study including 19 healthy participants and 20 patients with NCNP but without TMD symptoms. TMJ kinematics was measured during mouth opening and closing, jaw protrusion and jaw lateral deviation. Surface electromyography was used to record the muscle activity of the anterior temporalis, masseter, sternocleidomastoid and upper trapezius while clenching. Furthermore, cervical posture, cervical range of motion (ROM) and pressure-pain threshold of the neck and masticatory muscles were measured.

RESULTS

Compared with the healthy group, the NCNP group showed significantly reduced upper cervical rotation ROM (p = .041) and increased condylar path length (p = .02), condylar translation (opening p = .034, closing p = .011) and mechanical pain sensitivity of the upper trapezius (p = .018). Increased condylar translation was significantly correlated with reduced upper cervical mobility and poor cervical posture (r = -0.322 to -0.397; p = .012-.046).

CONCLUSION

Increased condylar translation and path length in patients with NCNP may indicate poor control of TMJ articular movement, which may result from neck pain or may be a compensation for limited neck mobility. Evaluation of excessive TMJ translation may be considered in patients with NCNP.

Multifidus Muscle Contractility Deficit Was Not Specific to the Painful Side in Patients with Chronic Low Back Pain During Remission: A Cross-Sectional Study

Purpose

Morphology studies demonstrated that patients with chronic low back pain (CLBP) have bilateral multifidus muscle (LM) atrophy. This atrophy should result in LM contractility deficit bilaterally. Additionally, a recent study showed the effect of sex on LM thickness. Researchers proposed percentage LM contractility (LM_CONT) as standardization to enable the comparison across participants. This study aimed to determine side-to-side difference in LM_CONT and to determine the difference in LM_CONT between males and females.

Patients and Methods

Twenty-five healthy individuals (NoLBP group; 10 males and 15 females) and 35 with CLBP (CLBP group; 16 males and 19 females; 23 unilateral pain and 12 bilateral pain) were recruited. Ultrasound imaging was used to measure LM thickness at rest, during maximum voluntary isometric contraction, and during combined maximum voluntary isometric contraction with electrical stimulation. These data were used to calculate LM_CONT. For unilateral CLBP, right and left LM_CON were renamed to painful and non-painful sides.

Results

Data demonstrated no significant difference (p > 0.05) between right (87.3 ± 13.7%) and left (87.2 ± 14.0%) in NoLBP, right (71.2 ± 15.7%) and left (76.5 ± 19.7%) in bilateral CLBP, and painful (70.3 ± 17.5%) and non-painful (77.7 ± 18.4%) in unilateral CLBP. No difference (p > 0.05) was found between males and females in both NoLBP (male 84.8 ± 6.5%, female 88.9 ± 15.4%) and CLBP groups (male 76.3 ± 15.5%, female 71.9 ± 14.0%).

Conclusion

The findings suggested that LM contractility deficit in CLBP is not specific to painful side. No effect was found of sex on LM contractility. Therefore, we can use averaged LM activation across painful and non-painful sides and across males and females to compare between NoLBP and CLBP groups.

Reliability of lumbar multifidus ultrasound assessment during the active straight leg raise test

BACKGROUND

Previous evidence showed altered lumbar multifidus (LM) activation in populations with chronic nonspecific low back pain (LBP). We aimed to investigate the test-retest and inter-examiner reliability of ultrasound imaging (US) for assessing LM thickness at rest and activation during the active straight leg raise test (ASLR) and the association between thickness changes with clinical outcomes.

METHODS

Fifty-two patients with LBP and two examiners (one experienced and one novice) participated in this study. A total of 18 B-mode images at L4-L5 or L5-S1 level (both sides, 3 at rest and 6 during ASLR) were collected. For assessing test-retest reliability, the experienced examiner repeated the procedure after 7 days. Intraclass correlation coefficients (ICC), standard error of measurements (SEM) and minimal detectable changes (MDC) were calculated.

RESULTS

Inter-examiner agreement was good to excellent (ICC3,2 = 0.71-0.92) and test-retest reliability was excellent (ICC3,1 = 0.91-0.98). Mean average of multiple measurements improved the agreement. Greater LM thickness at rest (p < .05) and greater thickness change after 3 s (p < .01) and 10 s (homolateral side, p < .01; contralateral side, p < .05) were associated with less pain intensity.

CONCLUSIONS

US is a reliable method to assess the LM thickness at rest and contracted during the ASLR in patients with LBP. The measurement at 3 s after maintaining ASLR, as well as the use of the mean of three measurements, has been shown to be the most reliable method for measuring LM muscle thickness during ASLR.