Flexion and rotation of the trunk and lifting at work are risk factors for low back pain: results of a prospective cohort study (original) (raw)
The aim of this study was to evaluate relationships between the revised NIOSH lifting equation (RNLE) and risk of low-back pain (LBP). Background: The RNLE is commonly used to quantify job physical stressors to the low back from lifting and/or lowering of loads. There is no prospective study on the relationship between RNLE and LBP that includes accounting for relevant covariates. Method: A cohort of 258 incident-eligible workers from 30 diverse facilities was followed for up to 4.5 years. Job physical exposures were individually measured. Worker demo-graphics, medical history, psychosocial factors, hobbies, and current LBP were obtained at baseline. The cohort was followed monthly to ascertain development of LBP and quarterly to determine changes in job physical exposure. The relationship between LBP and peak lifting index (PLI) and peak composite lifting index (PCLI) were tested in multivariate models using proportional hazards regression. Results: Point and lifetime prevalences o...
Elders LA, Burdorf A. Interrelations of risk factors and low back pain in scaffolders
Occupational and Environmental Medicine
Objectives-To assess with a cross sectional study the interrelations between physical, psychosocial, and individual risk factors and diVerent end points of low back pain. Methods-In total, 229 scaVolders and 59 supervisors completed a questionnaire about manual handling of materials, awkward back posture, strenuous arm position, perceived exertion, psychosocial load, need for recovery, and general health. Physical load at the worksite was also measured with many frequent observations. Interrelations between risk factors and their relation with four end points of low back pain were investigated.
Objectives: To assess the evidence for a dose-response relationship between ROM, duration, and frequency of trunk flexion, and risk of occupational LBP. Methods: An electronic systematic search was conducted using Medline, Cumulative Index to Nursing and Allied Health Literature, EMBASE, and Scopus databases focusing on cohort and case-control studies. Studies were included if they focused on non-specific LBP and postural exposure, considering ROM, duration, or frequency of trunk flexion as independent variables. No language restriction was imposed. Included studies were assessed for risk of bias using the Newcastle-Ottawa Scale for observational studies and a summary of evidence is presented. Results: Eight studies were included and all were methodologically rated as high quality. The included studies yielded a total of 7023 subjects who were considered for risk analysis. Different outcome measures for postural exposure were adopted making meta-analysis difficult to perform. Conclusions: We could not find a clear dose-response relationship for work posture exposures and LBP. Limited evidence was found for ROM and duration of sustained flexed posture as risk factor for LBP. We found no evidence for frequency of trunk flexion as a risk factor for LBP.
Model for the work-relatedness of low-back pain
Scandinavian Journal of Work, Environment & Health, 2003
Lötters F, Burdorf A, Kuiper J, Miedema H. Model for the work-relatedness of low-back pain. Scand J Work Environ Health 2003;29(6):431-440.
A posture and load sampling approach to determining low-back pain risk in occupational settings
International Journal of Industrial Ergonomics, 2001
A posture and load sampling approach to measure physical exposures was implemented within a case-control study of low-back pain reporting. The purpose of this paper was to determine how well this method was able to identify known low-back pain risk factors. Subjects, including both cyclic production and non-cyclic support workers, were studied while working in an automotive assembly facility. The study included 104 (with 20 proxies) cases, workers who reported low-back pain at work, and 129 randomly selected controls. Results indicate significant associations between low-back pain reporting and peak spinal loads (OR=2.0 for compression), shift-average spinal loading (OR=1.7 for compression), percent of time with loads in the hand (OR=1.5), maximum flexion angle (OR=2.2), and percent of time spent forward flexed beyond 458(OR=1.3). Posture and hand load variables, considered to be intermediate exposure variables, were handled separately in multivariable regression analyses from variables of peak and average spine force which directly estimate tissue loading. The work and posture sampling approach is particularly useful for heterogeneous work situations where traditional task analysis is difficult and can provide information on work and tissue load parameters which have been directly associated with risk of reporting low-back pain. Relevance to industry This paper demonstrates the effectiveness of an observational method in quantifying workplace exposures to physical risk factors for low-back pain. The method works for both cyclic and non-cyclic work. Quantified risk assessment provides key information for decision makers trying to control injury rates in industrial systems.
Interrelations of risk factors and low back pain in scaffolders
2001
Objectives-To assess with a cross sectional study the interrelations between physical, psychosocial, and individual risk factors and diVerent end points of low back pain. Methods-In total, 229 scaVolders and 59 supervisors completed a questionnaire about manual handling of materials, awkward back posture, strenuous arm position, perceived exertion, psychosocial load, need for recovery, and general health. Physical load at the worksite was also measured with many frequent observations. Interrelations between risk factors and their relation with four end points of low back pain were investigated. Results-Interrelations were strong among self reported determinants of physical load but showed an inverted trend for both age and total working experience, which could indicate the presence of a healthy worker eVect. Weak relations existed between variables of psychosocial and physical load. The multivariate analyses showed a significant relation between high manual handling of materials, moderate perceived general health, high job demands, and low back pain in the past 12 months. Chronic low back pain was significantly correlated with high perceived exertion and moderate perceived general health. Severe low back pain was significantly correlated with awkward back postures, high need for recovery, and high job demands. Finally, low back pain with perceived disability was significantly related to strenuous shoulder positions and moderate perceived general health. All end points of low back pain were consistently associated with physical load whereas psychosocial aspects showed a more diverse pattern. Conclusions-The findings of this study suggest that work related risk factors may vary according to diVerent definitions of low back pain. Distinct patterns of risk factors might enhance diVerent expressions of it. ScaVolders are a group at high risk of developing persistent forms of low back pain.
Clinical Biomechanics, 1998
Objective. To determine the relative importance of modelled peak spine loads, hand loads, trunk kinematics and cumulative spine loads as predictors of reported low back pain (LBP). Background. The authors have recently shown that both biomechemical and psychosocial variables are important in the reporting of LBP. In previous studies, peak spinal load risk factors have been identified and while there is in vitro evidence for adverse effects of excessive cumulative load on tissue, there is little epidemiological evidence. Methods. Physical exposures to peak and cumulative lumbar spine moment, compression and shear forces, trunk kinematics, and forces on hands were analyzed on 130 randomly selected controls and 104 cases. Univariable and multivariable odds ratios of the risk of reporting were calculated from a backwards logistic regression analysis. Interrelationships among variables were examined by factor analysis. Results. Cases showed significantly higher loading on all biomechanical variables. Four independent risk factors were identified: integrated lumbar moment (over a shift), 'usual' hand force, peak shear force at the level of L& and peak trunk velocity. Substituting lumbar compression or moment for shear did not appreciably alter odds ratios because of high correlations among these variables. Conclusions. Cumulative biomechanical variables are important risk factors in the reporting of LBP. Spinal tissue loading estimates from a biomechanical model provide information not included in the trunk kinematics and hand force inputs to the model alone. Workers in the top 25% of loading exposure on all risk factors are at about six times the risk of reporting LBP when compared with those in the bottom 25%. Relevance Primary prevention, treatment, and return to work efforts for individuals reporting LBP all require understanding of risk factors. The results suggest that cumulative loading of the low back is important etiologically and highlight the need for better information on the response of spinal tissues to cumulative loading.
Risk factors for back pain incidence in industry: a prospective study
Pain, 1998
The objective of this study was to examine the relationship between physical and psychological risk factors on the one hand, and the occurrence of new episodes of back pain on the other hand. A prospective study was conducted with 12 months follow-up by means of selfadministered questionnaires. The study took place in the Cargo Department of a major Dutch airline company. The subjects for this study were 270 workers involved in heavy physical work. Only workers without back pain at baseline were included. Self-reported back pain and sick leave due to back pain during the follow-up period were measured. Of the 238 workers included in the analysis, 73 (31%) developed a new episode of back pain during the follow-up period, and 27 (11%) subjects reported sick leave due to back pain. Multiple logistic regression analysis showed that the history of back pain was the best predictor for the occurrence of a new episode of back pain during follow-up (OR 9.8; 95% CI 2.8-34.4 for subjects who had back pain more than twice in the past year). Low job satisfaction was also associated with an increased risk for the occurrence of back pain during follow-up (OR 1.2; 95% CI 1.01-1.4). Riding a forklift truck appeared to be a protective factor for the occurrence of back pain (OR 0.7; 95% CI 0.5-0.99). In this study the best predictors for the occurrence of back pain were the history of back complaints and low job satisfaction. Although it needs to be confirmed by future intervention studies, the results indicate that increasing job satisfaction may be a successful (co-)intervention for the prevention of back pain at the workplace. © 1998 International Association for the Study of Pain. Published by Elsevier Science B.V.