Industrial back belts and low back pain: Mechanisms and outcomes

The recent increased utilization of industrial back belts as personal protective equipment in the workplace has generated considerable controversy among occupational health and safety professionals in the United States. The purpose of this article is to review the literature regarding proposed mechanisms of action of these devices and studies related to outcome of belt utilization in the prevention of low back pain and disability in the workplace. At the present time, neither the suspected mechanisms of action nor the efficacy of these devices in the primary, secondary, and tertiary prevention of work-related low back pain has been adequately demonstrated in clinical trials. As a result, generally accepted guidelines regarding the safe use of belts in the occupational setting have not been established. Based on this review it is recommended that further well-controlled, prospective, randomized clinical trials are necessary to evaluate the effectiveness of these devices as personal protective equipment. During the interim, the decision to prescribe belts to employees in the workplace should be at the discretion of an adequately trained occupational health care provider. These devices should not be provided as an alternative to appropriate administrative and/or engineering controls.     

NIOSH提举指数在下背痛流行病学研究中的应用

[目的 ]探讨美国国家职业安全卫生研究所提出的手工作业提举指数 (LI)与下背痛患病率的关系。[方法 ]在 3个具有典型提举作业的工厂中采用流行病学横断面调查方法 ,利用NIOSH提出的提举指数进行接触负荷评价 ,按照Nordic肌肉骨骼症状分析调查表对 491名从事手工提举作业的工人和 3 4名无明显提举任务的行政人员进行问卷调查 ,并对静态肌力进行测试。根据提举指数分为 0 ,～ 1,～ 2 ,～ 3 ,>3共 5组。观察各组工人不同部位肌肉骨骼疾患的患病情况 ,并分析提举指数与下背痛患病的关系。 [结果 ]在肌肉骨骼症状中 ,下背痛的发生率最高。当LI增高时 ,下背痛的OR值也随之增加 ,但其峰值出现在～ 3组 (OR =1.3 5 ) ,而LI >3 ,其OR值并非最高 ,仅为 1.3 0。平均腰拉力最大的为～ 1组 ( 95 .5 9± 2 1.76)kg ,而对照组和LI >3组则分别为 ( 80 .3 6± 14 .49)kg、( 86.85± 2 0 .3 3 )kg。 [结论 ]提举指数对手工提举所引起的下背痛是一个有意义的危险度评价指标。过度手工提举活动可能降低腰拉力。     

腰椎保护带对模拟驾驶人员腰部疲劳的预防作用

目的观察模拟驾驶前后驾驶员腰部疲劳情况,研究腰带对驾驶员腰部疲劳的预防作用.方法通过表面肌电图(surface electromyogram,SEMG)检测、问卷调查及体格检查观察12例受试对象在无腰带模拟驾驶前后以及佩戴腰带驾驶前后驾驶员相关指标的变化情况.结果受试对象不佩戴腰带驾驶前、后及佩戴腰带驾驶前、后表面肌电中值频谱(median frequency,MF)分别为(47.35±6.07)、(39.26±5.79)、(47.21±6.02)、(43.44±6.26)Hz,平均功率频率(mean power frequency,MPF)分别为(69.86±7.08)、(59.12±7.19)、(69.86±7.08)、(63.88±7.49)Hz,无腰带驾驶前与佩戴腰带驾驶前比较,差异无显著性(P＞0.05);无腰带驾驶前与无腰带驾驶后比较,差异有显著性(P＜0.01);佩戴腰带驾驶前与佩戴腰带驾驶后比较,差异有显著性(P＜0.01);无腰带驾驶后与佩戴腰带驾驶后比较,差异有显著性(P＜0.01).受试对象不佩戴腰带驾驶前、后及佩戴腰带驾驶前、后闪烁融合频率[(35.64±2.82)、(42.31±4.68)、(35.96±3.05)、(39.79±3.36)Hz]和明视持久度(65.77%±3.94%、56.83%±5.60%、65.88%±3.92%、62.27%±2.91%)等指标也有一定程度的变化.结论模拟驾驶一定时间后可以引起腰部肌肉的疲劳,腰带对模拟驾驶造成的腰部疲劳有一定的预防作用.     

A comparison of isometric strength and dynamic lifting capacity in men with work-related low back injuries

Job classification, return to work status, and job placement are determined by the results of lifting capacity tests. Lifting capacity is often assessed by maximum static or dynamic physical exertions. The purpose of this study was to compare maximum isometric lifting strength with maximum dynamic lifting capacity in subjects with work-related low back injury. Twenty-seven men performed five dynamic lifting tasks and two isometric strength tests. The mean Pearson product-moment correlation between maximum isometric lifting strength measurements and maximum dynamic lifting capacity measurements was .51 with a range of .30–.73. The results indicate low to moderate associations between isometric strength measurements and lifting capacity suggesting that estimates of functional lifting capacity should not be based on static measurements alone. Dynamic lift tests are often a better simulation of the task being assessed and may be more appropriate for a back-injured population.     

The effect of obesity on postural stability during a standardized lifting task

The objective of this study was to assess the effect of obesity on postural stability during a standardized lifting task. Twelve young males, six obese and six non-obese, completed three replications of repeated six lifts (at a rate of six lifts per minutes) at two levels of loads (10% and 25% of capacity) crossed with two levels of orientation (0° and 45° from sagittal plane). Postural stability measures showed that center of pressure sway path and sway area were ～21% and ～53% lower with obesity, respectively. Additionally, frequency band of amplitude spectrum in the medial lateral direction at 0° lifting orientation was significantly lower with obesity. The results suggest that obesity, as measured by body mass index, does not impair balance control in healthy young males when lifting load is relative to the capacity.     

Effects of a Worksite Supervised Adapted Physical Activity Program on Trunk Muscle Endurance,Flexibility, and Pain Sensitivity Among Vineyard Workers

Objectives: In viticulture, the prevalence of low back pain is particularly high among vineyard workers exposed to sustained and awkward postures. One promising setting for low back pain prevention resides in the implementation of workplace physical activity. Methods: This nonrandomized pilot study aims at evaluating the effects of a worksite supervised adapted physical activity program among 17 vineyard workers volunteered to enter either an intervention group (n = 10) or a control group (n = 7).The intervention group followed a physical activity program for 8 weeks involving (1) 15 minutes of warm-up every working day and (2) two weekly 1-hour adapted physical activity sessions targeting trunk muscle endurance and flexibility. The control group was advised to continue normal physical activity. Evaluations were carried out at weeks 0, 4, 8, and 12. Physical capacity was assessed using flexibility tests for the trunk, along with trunk muscle flexor and extensor endurance tests. Finally, pain sensitivity was evaluated by assessing pressure pain thresholds over 14 anatomical locations in the low back region. Results: For the intervention group, the endurance of the trunk extensor and flexor significantly increased from baseline to week 8 as well as the pressure pain thresholds. No change was observed for the control group over the same period. Conclusions: These encouraging results in combination with the high adherence rate set interesting foundations for the promotion of worksite supervised adapted physical activity and, most likely, offer a new promising approach to prevent low back pain among vineyard workers.     

Prevalence of spinal pain in a population of Bosnia and Herzegovina

ObjectivesTo determine the prevalence and risk factors of spinal pain in the population of Bosnia and Herzegovina (BiH).MethodsThis was a cross-sectional survey conducted online in November/December 2018. Participants were inhabitants of BiH of both sexes, aged ≥ 16 years. The sample was stratified based on region and demographic characteristics. Current pain was analyzed; point prevalence was measured.ResultsWe received 1048 responses, of which data from 1017 could be used. The prevalence of spinal pain in BiH was 70.9%: 75.5% in women (n = 440) and 64.7% in men (n = 281). Low back pain (LBP) was more common compared to neck pain (NP) and thoracic pain (TP) in both sexes and all age groups. Significant associations with spinal pain in the bivariate analysis were found for the following groups: women, aged from 30 to 50 years, with high school education, employed persons and retirees, spinal pain in parents, smoking, irregular physical activity, longer use of TV or computer/mobile phone per day.ConclusionTo our knowledge, this is the first study of the prevalence of spinal pain in BiH. Some factors associated with spinal pain are modifiable. Therefore, public health interventions should target those factors to reduce the burden of spinal pain in BiH.     

Determinants of Economic Cost Related to Low Back Pain among Nurses at a University Hospital

Abstract

The objectives of this study were to determine the economic cost related to low back pain (LBP) among nurses, and to identify factors associated with this cost. All 998 nurses at the National Taiwan University Hospital (NTUH) were asked to complete a questionnaire designed to examine whether the nurses had experienced LBP and whether their LBP had been related to the incurring of economic cost between May 1, 1990, and April 30, 1991. Of the 863 respondents, 417 had had LBP and 102 of these had incurred economic costs related to the LBP. Personal interviews of the 102 nurses, as well as of an additional four nurses who had resigned due to LBP within the 12 months, were performed to determine the related economic costs. The total monthly costs over the 12 months ranged from U.S. 105,405 to 149,083. Twenty percent of the 106 cases were responsible for 70% of the total overall cost. There was no difference in demographics between the two groups of non-LBP and LBP-without-cost. However, statistical analysis using logistic regression showed that the occurrence of economic cost was positively associated with subjective pain, lifting and carrying babies and small children at home, and age or work years or parity. In addition, multiple linear regression analysis showed that medical cost was positively associated with parity and sick leave; and productivity loss was associated with sick leave, lifting and carrying babies at home, unspecified housework, patient transport, and performing cardiopulmonary resuscitation.     

Effect of instructions to simulate a back injury on torque reproducibility in an isometric lumbar extension task

The purpose of this study was to investigate the differences in test-retest reliability between maximal and simulated back injury efforts in an isometric lumbar extension task and to test the hypothesis that voluntary attempts to simulate a back injury would yield less consistent torque production than maximal efforts. Twenty subjects were asked to undergo lumbar extensor testing at seven different positions in a lumbar extension machine. Each subject was tested twice in a maximal effort condition and twice with instructions to simulate a back injury. The order of the conditions was counterbalanced across subjects so that half of the subjects performed the maximal effort tests first and half performed the simulated effort first. Results indicated high test-retest correlations at all angles in both conditions. There were no differences in test-retest reliability between effort conditions. Therapist ratings of consistency did not differ between conditions and therapists could not discriminate between conditions on the basis of effort consistency. In the simulated condition subjects produced reliable, submaximal torque plots consistent with previous data indicating similar reliability at submaximal levels. It was concluded that use of test-retest torque consistency as a measure of sincerity of effort is premature and may be misleading.     

The role of physical and psychological factors in occupational low back pain: a prospective cohort study

OBJECTIVE—To examine risk factors for onset of low back pain (LBP) in healthcare workers.
METHODS—Nursing students, during their 3 year training period, and 1 year after training were studied in a prospective cohort study, with repeated self reported measurements of determinants of LBP at 6 monthly intervals for 3 years during training, and after a 12 month interval there was an additional final follow up.
RESULTS—During training, increased risk of new episodes of LBP was associated with having had LBP at baseline, with part time work, and with a high score on the general health questionnaire (GHQ). A high GHQ score preceded the onset of LBP, in such a way that a high score at the immediately previous follow up increased risk of LBP at the next follow up. 12 Months after training, a history of recurring LBP during training increased the risk of a new episode as did having obtained work as a nurse. A high GHQ score at this follow up was also associated with a concurrently increased risk. Pre-existing GHQ score, either at the end of training or at baseline, had no effect on risk of LBP 12 months after training.
CONCLUSIONS—Other than a history of LBP, pre-existing psychological distress was the only factor found to have a pre-existing influence on new episodes of LBP. Increased levels of psychological distress (as measured by the GHQ) preceded the occurrence of new episodes of pain by only short intervening periods, implying a role for acute distress in the onset of the disorder. This finding suggests that management of the onset of occupational LBP may be improved by management of psychological distress.


Keywords: low back pain; nurses; psychological factors     

The Use of Back Belts to Increase Intraabdominal Pressure as a Means of Preventing Low Back Injuries: A Survey of the Literature

Abstract

Published reports of relevant empirical research do not suggest a consistent relationship between intraabdominal pressure and the activity of the erector spinae muscles or the magnitude of the intradiscal pressure during lifting. Intraabdominal pressure varies in response to load magnitude and lift method, but there is no pattern of activity that would suggest that an increase in intraabdominal pressure decreases intradiscal pressure. Early models of back biomechanics predicted that the increase in intraabdominal pressure relieved the compressive forces on the low back by providing an extensor momen. In the newer models, intraabdominal pressure functions to stabilize the loaded spine. Studies of human subjects fail to consistenlly show any clear biomechanical advantage from using a back belt. Some studies suggest a slight decrease in back injury incidence when using a back belt; however, there are conflicting results regarding the severity of the injuries involved and the cost-effectiveness of back belts.     

综合治疗部队官兵非特异性下腰痛的临床观察

目的 研究微波治疗、普通针刺+电针治疗和运动疗法综合治疗部队官兵训练性非特异性下腰痛的临床疗效.方法 选择白求恩国际和平医院康复医学科门诊2017年8月～2018年1月训练性非特异性下腰痛官兵59例,将其分为治疗组29例和对照组30例,对照组只进行健康宣教和常规药物治疗,治疗组在对照组基础上采用微波治疗、普通针刺+电针...     

The relationship between low back magnetic resonance imaging, surgery, and spending: impact of physician self-referral status

Objective. To examine the relationship between use of magnetic resonance imaging (MRI) and receipt of surgery for patients with low back pain. Data Sources. Medicare claims for a 20 percent sample of beneficiaries from 1998 to 2005. Study Design. We identify nonradiologist physicians who appear to begin self‐referral arrangements for MRI between 1999 and 2005, as well as their patients who have a new episode of low back pain care during this time. We focus on regression models that identify the relationship between receipt of MRI and subsequent use of back surgery and health care spending. Receipt of MRI may be endogenous, so we use physician acquisition of MRI as an instrument for receipt of MRI. The models adjust for demographic and socioeconomic covariates as well as month, year, and physician fixed effects. Data Collection/Extraction Methods. We include traditional, fee‐for‐service Medicare beneficiaries with a visit to an orthopedist or primary care physician for nonspecific low back pain, and no claims for low back pain in the year prior. Principal Findings. In the first stage, acquisition of MRI equipment is a strongly correlated with patients receiving MRI scans. Among patients of orthopedists, receipt of an MRI scan increases the probability of having surgery by 34 percentage points. Among patients of primary care physicians, receiving a low back MRI is not statistically significantly associated with subsequent surgery receipt. Conclusions. Orthopedists and primary care physicians who begin billing for the performance of MRI procedures, rather than referring patients outside of their practice for MRI, appear to change their practice patterns such that they use more MRI for their patients with low back pain. These increases in MRI use appear to lead to increases in low back surgery receipt and health care spending among patients of orthopedic surgeons, but not of primary care physicians.     

Information in a Dutch GP registration system about high risks on long-lasting sickness absence: A cross sectional exploration in their registration system

Background: Low back pain (LBP) is a frequent diagnosis for sickness absence. The process of sick-listing is complex, and the doctor must integrate information from several levels in the decision. Objective: The aim of this paper is to describe the main determinants of sickness absence for LBP. Methods: We conducted a non-systematic search in Medline and personal files to identify determinants of sickness absence, and structured these into four levels of the sick-listing process. These levels are characteristics of 1) the sick-listed worker, 2) the sick-listing doctor, 3) the workplace, and 4) the cultural and economic conditions of the society. Results: Important characteristics of the sick-listed person seem to be poor mental health, including negative beliefs about LBP. Also, comorbidity and lack of coping abilities are found associated to sickness absence. The impact of the doctors’ personal beliefs about LBP is not clear. Doctors in general seem to be frustrated by their gatekeeper role and the influence of other healthcare providers on the sick-listing decision. The workplace is an important factor in the sick-listing process, but the impact of physical working conditions is of less importance than social support, job control, and demands. On the society level, the economic awards in sickness absence and the general acceptance of being sick listed seem to be of importance for the individual's decision to claim sick leave. Conclusion: The sick-listing process for LBP is complex, and the determinants are mostly non-medical. It seems important to adopt a broad perspective of how a worker copes with pain and how these coping strategies interact with cultural, economic, and societal determinants of sickness certification.     

自制动力性胸腰椎支具治疗腰背痛的临床疗效分析

目的探讨自制动力性胸腰椎支具在腰背痛中的治疗作用。方法自行研制动力性胸腰椎支具,应用该支具治疗132例腰背痛患者,应用疼痛视觉模拟评分法(VAS)和罗兰-摩理斯腰背痛生活障碍问卷(Roland-Morris Disability Questionnaire)对临床效果进行综合评价。结果所有病例均获得随访,随访时间2～6个月,平均5个月,患者症状明显改善,无明显并发症。结论动力性胸腰椎支具具有良好的弹性固定作用,可进行主动运动,是治疗腰背痛的有效方法。     

自制动力性胸腰椎支具治疗腰背痛的临床疗效分析

目的探讨自制动力性胸腰椎支具在腰背痛中的治疗作用。方法自行研制动力性胸腰椎支具,应用该支具治疗132例腰背痛患者。应用疼痛视觉模拟评分法（VAS）和罗兰一摩理斯腰背痛生活障碍问卷 （Roland-Morns Disability Questionnaire）对临床效果进行综合评价。结果所有病例均获得随访,随访时间2-6个月,平均5个月,患者症状明显改善,无明显并发症。结论动力性胸腰椎支具具有良好的弹性固定作用,可进行主动运动,是治疗腰背痛的有效方法。     

The Effects of a Four-Week Muscle Strengthening Program on Maximum Acceptable Lifting Load

The purpose of this study is to investigate the effects of a traditional strengthening program on subjects' maximum acceptable lifting load. Nineteen (nine males, ten females) university students volunteered for the present study. They were randomly divided into a training group (five males, seven females) and a control group (four males, three females). The training group participated in 12 sessions of alternate day traditional dead weight strengthening programs for a period of 4 weeks. The measurements of the training effects included assessment of the maximum acceptable lifting load by psychophysical approach and isokinetic peak torque of the back extensors, knee extensors, shoulder abductors, and elbow flexors. Multivariate ANOVA was used to test for the training effect. Results revealed significant improvement in the maximum acceptable lifting load (p < 0.001) and back extensors peak torque (p = 0.039) after 4 weeks of training. It is concluded that a 4-week free weight muscle training program is effective in improving an individual's maximum acceptable lifting load. This type of physical training program may be useful to people engaged in manual material handling tasks.     

Evaluation of a postgraduate educational programme for occupational physicians on work rehabilitation guidelines for patients with low back pain

OBJECTIVES—The postgraduate educational programme for occupational physicians on guidelines for work rehabilitation of patients with low back pain was evaluated as to what extent did knowledge of the guidelines increase, and did the workers improve their performance at work.
METHODS—An experimental group (n=25) attended an educational programme and a reference group did so (n=20) 6 months later. Knowledge and performance were assessed for both groups, before and after education of the experimental group. Knowledge was assessed for the reference group after education.
RESULTS—Knowledge increased significantly more in the experimental group. The reference group's score increased further after education. The experimental group's adjusted gain score for performance indicators was significantly positive. Analysis of covariance also showed a significant effect for the experimental group for increased performance score.
CONCLUSIONS—The educational programme improved the quality of care because knowledge and performance of occupational physicians improved and complied better with practice guidelines.


Keywords: evaluation; postgraduate education; occupational physicians; low back pain; guidelines     

The Effects of a Graded Activity Intervention for Low Back Pain in Occupational Health on Sick Leave,Functional Status and Pain: 12-Month Results of a Randomized Controlled Trial

Introduction: Behaviorally oriented graded activity interventions have been suggested for sick-listed workers with low back pain on return to work, but have not been extensively evaluated. Methods: One hundred and thirty-four workers were randomly assigned to either a graded activity intervention (n = 67) or usual care (n = 67) and followed-up for 12 months. Results: The graded activity group returned back to work faster with a median of 54 days compared to 67 days in the usual care group. The graded activity intervention was more effective after approximately 50 days post-randomization (HRR = 1.9, CI = 1.2–3.1, p = 0.01). Differences between the groups in number of recurrent episodes, total number of days of sick leave due to low back pain, and total number of days of sick leave due to all diagnoses, were in favor of the graded activity group, although not statistically significant. No effects of the graded activity intervention were found for functional status or pain. Conclusion: Graded activity intervention is a valuable strategy to enhance short-term return to work outcomes.