Assessment of low back disorders risk based on allowable weight limits for manual lifting in Iran.

In 2011, load limits for manual lifting were adopted in Iran to protect workers from low back injury without prior testing of accuracy with Iranian workers. This investigation examined how accurate the adopted ACGIH TLVs at the allowable limits predict risk for LBP disorders for a group of Iranian workers using biomechanical criteria. Testing took place in the laboratory with participants completing a series of 2-handed lifting tasks as defined in the Iranian Guideline for Manual Lifting. To test accuracy, both compression and shear forces were estimated for fifteen male Iranian workers who completed 25 lift combinations that varied in height and reach with the maximal allowable load. The findings, when compared to a risk threshold of 3400 N compression and 700 N shear, showed above-threshold forces for compression and little-to-no safety margins with repetitive lifting for most lifts at torso height and below. Since Government, employers and workers use these guidelines to decide on work/workplace design; these guidelines require further review and revision based on the anthropometrics of Iranian people.

The assessment of material handling strategies in dealing with sudden loading: the effects of load handling position on trunk biomechanics.

Back injury caused by sudden loading is a significant risk among workers that perform manual handling tasks. The present study investigated the effects of load handling position on trunk biomechanics (flexion angle, L5/S1 joint moment and compression force) during sudden loading. Eleven subjects were exposed to a 6.8 kg sudden loading while standing upright, facing forward and holding load at three different vertical heights in the sagittal plane or 45° left to the sagittal plane (created by arm rotation). Results showed that the increase of load holding height significantly elevated the peak L5/S1 joint compression force and reduced the magnitude of trunk flexion. Further, experiencing sudden loading from an asymmetric direction resulted in significantly smaller peak L5/S1 joint compression force, trunk flexion angle and L5/S1 joint moment than a symmetric posture. These findings suggest that handling loads in a lower position could work as a protective strategy during sudden loading.

Preparing difficult clients to return to work.

OBJECTIVE: Investigate the effect of the symptom magnification syndrome (SMS) behavior pattern on industrial rehabilitation on return to work and maintenance at work. PARTICIPANTS: A sample of 99 clients with active workers' compensation claims was studied; 25 identified as having SMS. METHODS: A protocol-driven functional capacity evaluation (FCE) was administered and the presence of SMS was determined from a standard protocol that considered 13 factors. RESULTS: Upon conclusion of intervention, 80 of the 99 clients were classified as ready to return to full-time usual and customary employment. The readiness for full-time return to work among those who did not have SMS (84%) was not statistically different from those with the syndrome (72%). Six months after discharge, follow-up work status data were obtained for 63 clients. Among those that did not display SMS, 76% continued to work full time, while 39% of those initially identified as SMS were working, a statistically significant difference. CONCLUSIONS: SMS had no significant bearing on work readiness, but appears to impact maintenance of employment. The value of return to work on a modified basis may need to be reconsidered, because none of the clients who had been discharged ready for modified work were employed at the six-month follow-up.

Early opioid prescription and subsequent disability among workers with back injuries: the Disability Risk Identification Study Cohort.

STUDY DESIGN: Prospective, population-based cohort study. OBJECTIVE: To examine whether prescription of opioids within 6 weeks of low back injury is associated with work disability at 1 year. SUMMARY OF BACKGROUND DATA: Factors related to early medical treatment have been little investigated as possible risk factors for development of long-term work disability among workers with back injuries. We have previously shown that about 1 of 3 of workers receive an opioid prescription early after a low back injury, and a recent study suggested that such prescriptions may increase risk for subsequent disability. METHODS: We analyzed detailed data reflecting paid bills for opioids prescribed within 6 weeks of the first medical visit for a back injury among 1843 workers with lost work-time claims. Additional baseline measures included an injury severity rating from medical records, and demographic, psychosocial, pain, function, smoking, and alcohol measures from a worker survey conducted 18 days (median) after receipt of the back injury claim. Computerized database records of work disability 1 year after claim submission were obtained for the primary outcome measure. RESULTS: Nearly 14% (254 of 1843) of the sample were receiving work disability compensation at 1 year. More than one-third of the workers (630 of 1843) received an opioid prescription within 6 weeks, and 50.7% of these (319 of 630) were received at the first medical visit. After adjustment for pain, function, injury severity, and other baseline covariates, receipt of opioids for more than 7 days (odds ratio = 2.2; 95% confidence interval, 1.5-3.1) and receipt of more than 1 opioid prescription were associated significantly with work disability at 1 year. CONCLUSION: Prescription of opioids for more than 7 days for workers with acute back injuries is a risk factor for long-term disability. Further research is needed to elucidate this association.

Risk assessment of patient handling with ambulance stretcher systems (ramp/(winch), easi-loader, tail-lift) using biomechanical failure criteria.

The research aims to carry out a detailed analysis of the loads applied by the ambulance workers when loading/unloading ambulance stretchers. The forces required of the ambulance workers for each system are measured using a load cell in a force handle arrangement. The process of loading and unloading is video recorded for all the systems to register the posture of the ambulance workers in different stages of the process. The postures and forces exerted by the ambulance workers are analyzed using biomechanical assessment software to examine if the work loads at any stage of the process are harmful. Kinetic analysis of each stretcher loading system is performed. Comparison of the kinetic analysis and measurements shows very close agreement for most of the cases. The force analysis results are evaluated against derived failure criteria. The evaluation is extended to a biomechanical failure analysis of the ambulance worker's lower back using 3DSSPP software developed at the Centre for Ergonomics at the University of Michigan. The critical tasks of each ambulance worker during the loading and unloading operations for each system are identified. Design recommendations are made to reduce the forces exerted based on loading requirements from the kinetic analysis.

Predicting return to work after low back injury using the Psychosocial Risk for Occupational Disability Instrument: a validation study.

INTRODUCTION: This paper reports on the predictive validity of a Psychosocial Risk for Occupational Disability Scale in the workers' compensation environment using a paper and pencil version of a previously validated multimethod instrument on a new, subacute sample of workers with low back pain. METHODS: A cohort longitudinal study design with a randomly selected cohort off work for 4-6 weeks was applied. The questionnaire was completed by 111 eligible workers at 4-6 weeks following injury. Return to work status data at three months was obtained from 100 workers. Sixty-four workers had returned to work (RTW) and 36 had not (NRTW). RESULTS: Stepwise backward elimination resulted in a model with these predictors: Expectations of Recovery, SF-36 Vitality, SF-36 Mental Health, and Waddell Symptoms. The correct classification of RTW/NRTW was 79%, with sensitivity (NRTW) of 61% and specificity (RTW) of 89%. The area under the ROC curve was 84%. CONCLUSIONS: New evidence for predictive validity for the Psychosocial Risk-for-Disability Instrument was provided. IMPLICATIONS: The instrument can be useful and practical for prediction of return to work outcomes in the subacute stage after low back injury in the workers' compensation context.

Factor structure of the pain disability index in workers compensation claimants with low back injuries.

OBJECTIVE: To examine the factor structure of a telephone-administered Pain Disability Index (PDI) and the effects of race and sex on the PDI. DESIGN: Computer-assisted telephone interviews of a cohort with occupational low back injuries. SETTING: General community. PARTICIPANTS: Missouri workers compensation claimants (N=1329) with low back injuries. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: PDI, levels of pain severity, Social Security Disability Insurance status, and the Fear-Avoidance Behavior Questionnaire. RESULTS: Results for the total sample and by race/sex group indicated support for a 2-factor model of the PDI corresponding to voluntary activities (eg, social, occupational, recreational) and obligatory activities (eg, activities of daily living, eating, sleeping). Additional psychometric analyses of the voluntary and obligatory subscales indicated adequate reliability and construct validity overall and in each of the race/sex groups. African Americans reported more pain-related disability on both subscales than whites. Women reported more disability on the voluntary subscale than men. CONCLUSIONS: The results support use of the PDI as a bidimensional measure of pain-related disability, with strong psychometric properties. They also support its administration by telephone.

ACC and back injuries: the relevance of pre-existing asymptomatic conditions.

The purpose of the ARCI (1992) and AI (198) Acts is to cover those who suffered from personal injury by accident. This purpose should not be distorted. This review does not aim to suggest that cover be extended to victims of disease. Equally it is inappropriate that imaging be used to detect asymptomatic, age-related change--or reveal asymptomatic abnormalities that do not place the patient at increased risk of symptoms over the general population--so as to unfairly deny coverage to the victims of accidents. This is particularly important to those who suffer personal injury to the lumbar spine where the cause is wholly or substantially an accident, and in whom, without the specified accident having occurred, personal injury (symptoms and disability) would have not been likely to occur. Physicians managing spinal disorders must correlate clinical findings with imaging studies when planning treatment. Those considering entitlement for cover under third party/ACC provisions must pay close attention to the history and clinical evaluation, correlating these with the investigation findings, and not assume that the abnormalities found on sensitive investigations are the cause of the symptoms.

Measuring quality of life in back patients: comparison of Health Status Questionnaire 2.0 and Quality of Life Inventory.

This paper is a reliability and validity test of the Health Status Questionnaire (HSQ) 2.0. In addition, the Quality of Life Inventory (QOLI) is compared with the HSQ 2.0 to assess concurrent validity. The study is unique because these instruments are assessed for the first time using a sample of chronic back patients. Practitioners will therefore now be able to evaluate important quality of life issues and treatment changes in this population. The HSQ 2.0 was generally found to be valid for these patients. However, two scale domains were not differentiated due to unique characteristics of spinal disease patients. The QOLI, due to the limitation of measuring only psychological well-being, did not measure problems specific to back patients.