Changes in paraspinal muscles and their association with low back pain and spinal degeneration: CT study

The objectives of the study were to evaluate the association between lumbar paraspinal muscle density, evaluated on computed tomography (CT) and age, sex and BMI; and to evaluate the association of those changes with low back pain (LBP) and spinal degeneration features in a community-based sample. This study was an ancillary project to the Framingham Study. A sample of 3,529 participants aged 40–80 years had a CT scan performed to assess aortic calcification. 187 individuals were randomly enrolled in this study. LBP in the last 12 months was evaluated using self-report questionnaire. Density (in Hounsfield units) of multifidus and erector spinae was evaluated on CT. The prevalence of intervertebral disc narrowing, facet joint osteoarthritis (FJOA), spondylolysis, spondylolisthesis and spinal stenosis were also evaluated. We used linear regression models to examine the association of paraspinal muscles density with age, sex, BMI, LBP, and spinal degeneration features. The results show that in our study, men have higher density of paraspinal muscles than women, younger individuals have higher density than older ones and individuals with lower weight have higher muscle density than overweight. No differences between individuals with and without LBP were found. Significant association was found between L4 multifidus/erector spinae density and FJOA at L4–L5; between multifidus at L4 and spondylolisthesis at L4–5; and between erector spinae at L4 and L5 with disc narrowing at L4–5 and L5–S1, respectively. We conclude that the paraspinal muscle density decreases with age, and increases BMI. It is associated with at some levels FJOA, spondylolisthesis and disc narrowing at the same level, but not associated with occurrence of LBP.     

The association between isoinertial trunk muscle performance and low back pain in male adolescents

The literature reports inconsistent findings regarding the association between low back pain (LBP) and trunk muscle function, in both adults and children. The strength of the relationship appears to be influenced by how LBP is qualified and the means by which muscle function is measured. The aim of this study was to examine the association between isoinertial trunk muscle performance and consequential (non-trivial) low back pain (LBP) in male adolescents. Healthy male adolescents underwent anthropometric measurements, clinical evaluation, and tests of trunk range of motion (ROM), maximum isometric strength (STRENGTH) and peak movement velocity (VEL), using an isoinertial device. They provided information about their regular sporting activities, history and family history of LBP. Predictors of “relevant/consequential LBP” were examined using multivariable logistic regression. LBP status was reassessed after 2 years and the change from baseline was categorised. At baseline, 33/95 (35%) subjects reported having experienced consequential LBP. BMI, a family history of LBP, and regularly playing sport were each significantly associated with a history of consequential LBP (p < 0.05). 85/95 (89%) boys participated in the follow-up: 51 (60%) reported no LBP at either baseline or follow-up (never LBP); 5 (6%) no LBP at baseline, but LBP at follow-up (new LBP); 19 (22%) LBP at baseline, but none at follow-up; and 10 (12%) LBP at both time-points (recurrent/persistent LBP). The only distinguishing features of group membership in these small groups were: fewer sport-active in the “never LBP” group); worse trunk mobility, in the “persistent LBP” group, lower baseline sagittal ROM in the “never LBP” and “new LBP” (p < 0.05). Regular involvement in sport was a consistent predictor of LBP. Isoinertial trunk performance was not associated with LBP in adolescents.     

Influence of age and duration of symptoms on fibre type distribution and size of the back muscles in chronic low back pain patients

Many studies have documented an association between chronic low back pain (LBP) and deficits in back muscle strength and endurance. The sub-optimal performance is believed to be the result of alterations in the size and structure of the muscle, although the long-standing issue of whether the observed changes precede or are a consequence of the pain remains unresolved. If consequent to the problem, and predominantly related to disuse of the muscles, then it may be expected that a relationship between muscle structure and symptom duration would exist. Lumbar paraspinal muscle samples were obtained from 59 chronic LBP patients using the percutaneous biopsy technique. The samples were subject to routine histochemical analysis for the examination of muscle fibre type characteristics and cytochemical architectural changes. In 55 of the patients, the gross cross-sectional areas of magnetic resonance images of the trunk muscles were also measured. Multivariate analysis showed that symptom duration was the strongest predictor of the individual proportions of the fast-fatigable type IIX fibres; with age and gender included in the model, nearly 30% of the variance in fibre type distribution could be accounted for. Duration of pain had no influence on fibre size. Gross muscle cross-sectional area correlated directly with lean body mass and inversely with age, but showed no relationship with symptom duration. Pathological changes in the internal fibre structure were more frequently encountered in older patients, and were independent of symptom duration. The results suggest that, over the long term, fibre type transformations rather than alterations in fibre size are the predominant changes to be found in the muscles of chronic LBP patients. The direction of change supports the results of many previous studies that have demonstrated corresponding differences in the fatigability of the muscles. There is a strong case for the early implementation of active measures to attempt to offset the development of these changes in back pain patients. Received: 9 June 2000 / Accepted: 20 June 2000     

慢性腰痛对脊旁多裂肌萎缩影响的临床研究

目的：明确慢性腰痛对脊旁多裂肌净横截面积大小及脂肪化程度的影响。方法：2010年3月至2013年8月对门诊治疗的腰痛患者进行回顾性分析,最终筛选出31例符合非特异性慢性腰痛患者,其中男19例,女12例;年龄23～55岁,平均36.4岁。主要症状是反复腰痛,病程大于1年,X线、CT、MRI均未见明显异常。采用MRI成像测量同一病例先后不同时间点多裂肌净横截面积及T2信号比率的变化,再获取2次MRI检查时VAS和Oswestry功能障碍评分,分析先后2次测量多裂肌净面积及T2信号比率的变化与腰痛的病程、VAS、Oswestry功能障碍评分的相关性,从而得出腰痛对脊旁多裂肌的影响。结果：同一病例第2次MRI检查多裂肌净横截面积明显小于第1次MRI检查,T2信号比率则明显高于第1次MRI检查（P<0.05）.多裂肌净横截面积减小率与VAS评分、病程和Oswestry功能障碍评分均呈正相关（P<0.001）,而T2信号比率增加率与VAS评分、病程和Oswestry功能障碍评分均无相关性（P>0.05）.结论：慢性腰痛是脊旁多裂肌萎缩和脂肪化的重要原因,腰痛时间、程度和功能障碍程度均与多裂肌萎缩呈正相关。     

Surface EMG in chronic low back pain

Chronic low back pain (CHLBP) occupies first place among factors restricting people’s life activity under the age of 45. Frequency of CHLBP occurrence oscillates between 60 and 80%. Dysfunction of the erector trunci is a fundamental cause of CHLBP. The aim of the study was to evaluate the usefulness of surface electromyography (EMG) as an identification method in CHLBP. EMG apparatus was connected to a PC equipped with the EMG-LAB programme. This programme allows the registration, transformation, analysis and projection of results on-line. A summary of complete examination is presented in the form of statistical values of parameters such as mean amplitude, mean density, background amplitude, background density, and upper amplitude and upper density. Plain, surface electrodes were attached to the skin overlying the erector spinae at the T7 and L4 vertebrae, approximately 3–4 cm from the midline of the back. Electrodes were positioned unilaterally on the right side. A reference electrode was positioned on the skin overlying the right arm. Sixty-two patients with CHLBP were examined (30 men and 32 women, mean age 41 ± 8 years). The control group consisted of 31 people without back problems (16 men and 15 women, mean age 39 ± 6 years). The statistical values of mean amplitude, mean density and upper amplitude were found to be higher in the control group at the T7 level. At the L4 level, mean amplitude, mean density, background amplitude, background density and upper amplitude were significantly higher in control group. The findings of this study show that (1) dysfunction of the erector spinae plays a significant role in CHLBP, and (2) this process applies to small and large motor units, but the character of these changes is different in particular muscles. Surface EMG is an objective, non-invasive method of examining function of the erector spinae in the author’s opinion. Received: 12 November 1998 Accepted: 5 January 2000     

Effects of pregnancy on lumbar motion patterns and muscle responses

BACKGROUND CONTEXT

The kinematics of the lumbar region and the activation patterns of the erector spinae muscle have been associated with the genesis of low back pain, which is one of the most common complications associated with pregnancy. Despite the high prevalence of pregnancy-related low back pain, the biomechanical adaptations of the lumbar region during pregnancy remain unknown.

椎间盘源性下腰痛的发病机制

目的探讨椎间盘源性下腰痛的发病机制。方法收集腰椎后路切除的17例椎间盘源性下腰痛患者的19个经腰椎间盘造影术证实的疼痛腰椎间盘;同时收集12个在MRI T2加权像上信号强度明显减弱、无腰痛症状的生理老化椎间盘和10个正常对照椎间盘,行组织学检查和P物质、神经丝蛋白和血管活性肠肽的免疫组织化学染色检查。结果椎间盘源性下腰痛患者的疼痛椎间盘在组织学上的显著特征表现为,一条从髓核至纤维环外层的血管化肉芽组织条带区,其间伴有1个或多个裂隙;肉芽组织条带区与椎间盘造影术后CT上显示的纤维环裂隙一致,肉芽组织之外的纤维环结构基本正常。生理老化椎间盘和正常对照椎间盘表现为与年龄相关的改变。免疫组织化学染色显示,疼痛椎间盘中P物质、神经丝蛋白和血管活性肠肽3种神经肽阳性神经纤维分布数量和比例,较正常对照椎间盘和生理老化椎间盘明显增多;神经纤维主要沿伴有裂隙的肉芽组织条带区分布;疼痛椎间盘髓核中可见P物质和神经丝蛋白的阳性神经纤维分布。结论椎间盘后方神经分布广泛的肉芽组织条带区是椎间盘造影术疼痛和椎间盘源性下腰痛的起源部位。肉芽组织条带可能起源于椎间盘的创伤修复过程。生理老化椎间盘和疼痛椎间盘的差异是后者形成组织学上的肉芽组织条带区。     

国外急性腰痛的治疗进展

急性腰痛为临床常见病,也称单纯性或非特异性急性腰痛.其病因主要为机械性外力损害,如搬提重物、扭转腰部,或长时间坐位,操作振动性工具等.损害部位以腰部软组织为主,如肌肉、筋膜、韧带、关节囊,还包括椎间关节及骶髂关节的损伤;椎间盘纤维环可能发生不全撕裂,但不伴有髓核向椎管内的突出,破裂椎间盘的渗出物可能造成神经根的炎性反应.急性发病及外伤史对诊断有意义.腰部或骶髂关节处可见弥漫性或局限性压痛,腰椎活动可能引发腰痛;腰痛可放射至臀部及下肢,但多在膝关节水平以上.损伤组织的痉挛可使患者呈被动的僵直体位,不能做屈或伸的运动[1].腰椎的放射学检查对诊断通常无帮助,仅作为排除性方法以区分出腰椎的骨折、肿瘤、脊柱滑脱等[2].……     

运动员脊柱源慢性腰痛的述评

慢性腰痛一直是困扰运动员的高发病之一,其中以脊柱源慢性腰痛占多数。本文对运动员慢性腰痛的发病率及原因,康复治疗评估进行综述。通过脊柱稳定系统作为损伤的理论基础来分析目前治疗的不足,为慢性腰痛的康复治疗与评估更加适合运动员群体提供参考。     

Prevalence of low back pain and factors associated with chronic disabling back pain in Japan

Purpose

This study aimed to report lifetime and 4-week low back pain (LBP) prevalence and examine factors associated with chronic LBP and back pain disability over a lifetime in a Japanese adult population.

Methods

In February 2011, 1,063,083 adults aged 20–79 years registered as internet research volunteers were randomly selected to participate in a questionnaire survey. The data from 65,496 respondents were analyzed to calculate age-standardized lifetime and 4-week prevalence. Chronic LBP and back pain disability were defined as LBP lasting for ≥3 months and a consecutive ≥4-day-long absence, respectively. Factors associated with chronic disabling back pain over a lifetime were examined by multiple logistic regression modeling.

Results

The lifetime LBP prevalence was 83 % and 4-week prevalence was 36 %; majority of the respondents had disability-free LBP. Smoking [adjusted odds ratio (aOR): 1.17; 95 % CI: 1.05, 1.30], lower educational level (aOR: 1.21; 95 % CI: 1.09, 1.34), history of disabling back pain among family members and/or significant others (aOR: 1.46; 95 % CI: 1.27, 1.67), occupational LBP (aOR: 1.34; 95 % CI: 1.16, 1.55), traffic injury (aOR: 2.81; 95 % CI: 2.07, 3.81), compensated work injury (aOR: 2.42; 95 % CI: 1.92, 3.05), radiating pain (aOR: 4.94; 95 % CI: 4.45, 5.48), low back surgery (aOR: 10.69; 95 % CI: 9.02, 12.68), and advice to rest upon back pain consultation (aOR: 3.84; 95 % CI: 3.36, 4.40) were associated with chronic disabling back pain over a lifetime.

Conclusions

LBP is common in Japan as in other industrialized countries. The association between the advice to rest and chronic disabling back pain supports recent treatment guidelines emphasizing continuation of daily activities.     

Differences in electromyographic activity in the multifidus muscle and the iliocostalis lumborum between healthy subjects and patients with sub-acute and chronic low back pain

The present study was carried out to examine possible mechanisms of back muscle dysfunction by assessing a stabilising and a torque-producing back muscle, the multifidus (MF) and the iliocostalis lumborum pars thoracis (ICLT), respectively, in order to identify whether back pain patients showed altered recruitment patterns during different types of exercise. In a group of healthy subjects (n=77) and patients with sub-acute (n=24) and chronic (51) low back pain, the normalised electromyographic (EMG) activity of the MF and the ICLT (as a percentage of maximal voluntary contraction) were analysed during coordination, stabilisation and strength exercises. The results showed that, in comparison with the healthy subjects, the chronic low back pain patients displayed significantly lower (P=0.013) EMG activity of the MF during the coordination exercises, indicating that, over the long term, back pain patients have a reduced capacity to voluntarily recruit the MF in order to obtain a neutral lordosis. In contrast, during the stabilisation exercises, no significant differences between patients and controls were found for the normalised EMG activity of the two muscles. These findings indicated that, during low-load exercises, no insufficiencies in back muscle recruitment were evident in either subacute or chronic back pain patients. During the strength exercises, the normalised activity of both back muscles was significantly lower in chronic low back pain patients (P=0.017 and 0.003 for the MF and ICLT, respectively) than in healthy controls. Pain, pain avoidance and deconditioning may have contributed to these lower levels of EMG activity during intensive back muscle contraction. The possible dysfunction of the MF during coordination exercises and the altered activity of both muscles during strength exercises may be of importance in symptom generation, recurrence or maintenance of low back pain.     

Effects of noxious stimulation and pain expectations on neuromuscular control of the spine in patients with chronic low back pain

Background context

Alterations of the neuromuscular control of the lumbar spine have been reported in patients with chronic low back pain (LBP). During trunk flexion and extension tasks, the reduced myoelectric activity of the low back extensor musculature observed during full trunk flexion is typically absent in patients with chronic LBP.

Purpose

To determine whether pain expectations could modulate neuromuscular responses to experimental LBP to a higher extent in patients with chronic LBP compared with controls.

Study design

A cross-sectional, case-control study.

Patient sample

Twenty-two patients with nonspecific chronic LBP and 22 age- and sex-matched control participants.

Methods

Trunk flexion-extension tasks were performed under three experimental conditions: innocuous heat, noxious stimulation with low pain expectation, and noxious stimulation with high pain expectation. Noxious stimulations were delivered using a contact heat thermode applied on the skin of the lumbar region (L4–L5), whereas low or high pain expectations were induced by verbal and visual instructions.

Outcome measures

Surface electromyography of erector spinae at L2–L3 and L4–L5, as well as lumbopelvic kinematic variables were collected during the tasks. Pain was evaluated using a numerical rating scale. Pain catastrophizing, disability, anxiety, and fear-avoidance beliefs were measured using validated questionnaires.

Results

Two-way mixed analysis of variance revealed that pain was significantly different among the three experimental conditions (F2,84=317.5; p<.001). Increased myoelectric activity of the low back extensor musculature during full trunk flexion was observed in the high compared with low pain expectations condition at the L2–L3 level (F2,84=9.5; p<.001) and at the L4–L5 level (F2,84=3.7; p=.030). At the L4–L5 level, this effect was significantly more pronounced for the control participants compared with patients with chronic LBP (F2,84=3.4; p=.045). Pearson correlation analysis revealed that increased lumbar muscle activity in full flexion induced by expectations was associated with higher pain catastrophizing in patients with chronic LBP (r=0.54; p=.012).

Conclusions

Repeated exposure to pain appears to generate rigid and less variable patterns of muscle activation in patients with chronic LBP, which attenuate their response to pain expectations. Patients with high levels of pain catastrophizing show higher myoelectric activity of lumbar muscles in full flexion and exhibit greater neuromechanical changes when expecting strong pain.     

Recent advances in the treatment of low back pain

Summary There is at the present time an epidemic of low back pain in the industrialized countries. Although the exact origin of such pain is still unknown, there is increasing awareness that the outcome is usually favourable. Only some 10% of those suffering an acute episode of back pain are incapacitated for more than 6 weeks. The causes of long standing back pain are being identified in an increasing number of patients. They include anatomical and pathological disturbances in the motion segment as well as psychological, social and political causes. There are numerous factors which influence the pathophysiology of the motion segment. The degree of loading has been successfully measured and delineated for various postures and exercises, including those at work. The nutritional pathways to the disc have been established and the effect of various external factors measured. Movement is good for the disc and the importance of continuous passive motion for the healing of diseased or injured connective tissues is now established. Activation of large muscle groups increases the production of the body's pain reducing encephalins. Early diagnosis and early mobilisation of the patient should be of benefit, and long term bed rest and inactivity must be prevented. Fewer cases will need operation in the future. Improved imaging techniques and better methods of operation and fixation will help those few who have a definite pathological lesion amenable to surgery.Current trends lecture SICOT 1984     

骶髂关节病损与腰腿痛

通过对６７例骶髂关节病损所致腰痛病人的临床分析，归纳出４种临床类型：（１）单纯性髂关节疼痛；（２）应力传导性疼痛；（３）感应性疼痛；（４）放射性疼痛。同时介绍了７种主要的物理检查方法。封闭是治疗骶髂关节病损所致腰腱痛的重要手段。     

腰痛的诊疗进展

背景 腰痛,又称下背痛,是引起功能障碍的主要原因.目的 在众多腰痛的诊断和治疗方法中,提供基于循征医学的腰痛诊断和治疗进展.内容 临床医生应该首先把腰痛患者归类为机械性、神经性或继发性腰痛,进而给予相应的检查和治疗.趋向 机械性腰痛不应该常规使用影像学检查.腰痛患者的一线药物治疗是对乙酰氨基酚或非类固醇类抗炎药.腰痛的...     

The association between pro-inflammatory biomarkers and nonspecific low back pain: a systematic review

BACKGROUND CONTEXT

About 85% of the patients with low back pain seeking medical care have nonspecific low back pain (NsLBP), implying that no definitive cause can be identified. Nonspecific low back pain is defined as low back pain and disability which cannot be linked to an underlying pathology, such as cancer, spinal osteomyelitis, fracture, spinal stenosis, cauda equine, ankylosing spondylitis, and visceral-referred pain. Many pain conditions are linked with elevated serum levels of pro-inflammatory biomarkers. Outcomes of interest are NsLBP and the level of pro-inflammatory biomarkers.

Gait adaptations in low back pain patients with lumbar disc herniation: trunk coordination and arm swing

Patients with chronic non-specific low back pain (LBP) walk with more synchronous (in-phase) horizontal pelvis and thorax rotations than controls. Low thorax–pelvis relative phase in these patients appears to result from in-phase motion of the thorax with the legs, which was hypothesized to affect arm swing. In the present study, gait kinematics were compared between LBP patients with lumbar disc herniation and healthy controls during treadmill walking at different speeds and with different step lengths. Movements of legs, arms, and trunk were recorded. The patients walked with larger pelvis rotations than healthy controls, and with lower relative phase between pelvis and thorax horizontal rotations, specifically when taking large steps. They did so by rotating the thorax more in-phase with the pendular movements of the legs, thereby limiting the amplitudes of spine rotation. In the patients, arm swing was out-of phase with the leg, as in controls. Consequently, the phase relationship between thorax rotations and arm swing was altered in the patients.     

A scientometrics analysis and visualization of low back pain

BackgroundAlthough low back pain (LBP) contributes to the global disease burden, literature on the scientometric analysis of low back pain is limited.ObjectiveThis study aimed to demonstrate the research state and capture developmental dynamics of low back pain utilizing scientometric analysis and visualization methods.MethodsLiterature on low back pain from 2011 to 2020 was retrieved from the Web of Science core collection. CiteSpace software was used to generate the relevant knowledge map and carry out scientometric analysis on the volume of literature, cooperation between countries/regions and research institutions, disciplines, journals, highly cited references, and keywords. Research hotspots and trends of the included literature were then stated.ResultsA total of 27,968 publications were obtained and the number of annual publications maintained growth continually. Australia and the University of Washington had the maximum centrality. The USA and the University of Sydney were the most prolific country and institution respectively, thus indicating that they are important in this field. Publications were devoted to the disciplines of neurology, orthopedics and rehabilitation. The highest cited journal is Spine (18478), followed by European Spine Journal (11344) and Pain (11097). The systematic review, disease burden, epidemiology, clinical practice recommendations, and primary care management are the key subjects covered by highly cited papers. The keywords were primarily concerned with pain etiology, disease type, clinical treatment, and trials. Burst keywords in LBP were controlled trial, practice guideline, stability, adolescent, individual, activation and expression, which can be regarded as research hotspots and frontiers.ConclusionIn conclusion, the data clearly shows a consistent increase in LBP studies. The historical review provides insight into LBP as well as valuable information for researchers to identify new perspectives on potential cooperative institutions, hot topics, and a strong foundation for future research.     

Pocket-size,portable surface EMG device in the differentiation of low back pain patients

Summary The relevance of surface EMG of the paraspinal muscles measured by a portable, pocket-size device with a special amplifier was evaluated in different low back pain groups. Patients with only local low back pain had significantly higher EMG activities than those with unilateral radiating pain without verified disc herniation, those with verified disc herniation, and controls, but there were no differences between the latter three groups. Pain clearly modified paravertebral muscle activity, as the patients experiencing pain during the recording showed significantly higher EMG activities than those with no pain. It is concluded that surface EMG is a valid tool for indirectly assessing pain in low back pain patients but not for classification into different diagnostic groups.