The effect of clinically elevated body mass index on physiological stress during manual lifting activities

Individuals with a body mass index (BMI) classified as obesity constitute 27.7% of U.S. workers. These individuals are more likely to experience work-related injuries. However, ergonomists still design work tasks based on the general population and normal body weight. This is particularly true for manual lifting tasks and the calculation of recommended weight limits (RWL) as per National Institute of Occupational Safety & Health (NIOSH) guidelines. This study investigates the effects of BMI on indicators of physiological stress. It was hypothesized that, for clinically elevated BMI individuals, repeated manual lifting at RWL would produce physiological stress above safety limits. A repetitive box lifting task was designed to measure metabolic parameters: volume of carbon dioxide (VCO2) and oxygen (VO2), respiratory exchange ratio (RER), heart rate (HR), and energy expenditure rate (EER). A two-way ANOVA compared metabolic variables with BMI classification and gender, and linear regressions investigated BMI correlations. Results showed that BMI classification represented a significant effect for four parameters: VCO2 (p < 0.001), VO2 (p < 0.001), HR (p = 0.012), and EER (p < 0.001). In contrast, gender only had a significant effect on VO2 (p = 0.014) and EER (p = 0.017). Furthermore, significant positive relationships were found between BMI and VCO2 (R2 = 59.65%, p < 0.001), VO2 (R2 = 45.01%, p < 0.001), HR (R2 = 21.86%, p = 0.009), and EER (R2 = 50.83%, p < 0.001). Importantly, 80% of obese subjects exceeded the EER safety limit of 4.7 kcal/min indicated by NIOSH. Indicators of physiological stress are increased in clinically elevated BMI groups and appear capable of putting these individuals at increased risk for workplace injury.

Occupational interventions for the prevention of back pain: Overview of systematic reviews

INTRODUCTION

We conducted an overview of systematic reviews of interventions for the prevention of low back pain (LBP) that can be conducted in a workplace setting.

METHODS

An electronic literature search was performed in Medline, EMBASE, and the Cochrane Library. Published peer-reviewed systematic reviews and meta-analyses, which described interventions for the primary or secondary prevention of LBP applicable to a workplace setting, were eligible for inclusion. The methodological quality of the included systematic reviews was assessed with the AMSTAR tool. The primary outcome of interest was the incidence of LBP; secondary outcomes were LBP-associated absenteeism, activity interference, and costs related to LBP.

RESULTS

Twenty-eight eligible articles published between 1994 and 2016 were included in a qualitative synthesis following our screening of abstracts and full-text articles. The AMSTAR rating revealed 14 reviews of high, 10 of moderate, and 4 of low methodological quality. The identified interventions included workplace modifications (6 reviews, 10 studies, 6,751 subjects); shoe insoles (4 reviews, 6 studies, 2,356 subjects); and lumbar supports and other assistive devices (15 reviews, 18 studies, 60,678 subjects). Educational interventions investigated were back schools (10 reviews, 30 studies, 9,973 subjects); manual material handling techniques/advice (6 reviews, 24 studies, 10,505 subjects); and other forms of instruction including pamphlets, booklets, and other media (four reviews, 14 studies, 11,991 subjects). Exercise interventions, investigated in 12 reviews (35 studies, 19,330 subjects), showed moderate quality evidence of effectiveness for exercise interventions alone or in conjunction with educational interventions; no other type of intervention was consistently effective in the prevention of LBP or LBP-associated outcomes of interest.

CONCLUSIONS

Our overview provides evidence of effectiveness for exercise with or without educational interventions in the prevention of LBP.

PRACTICAL APPLICATIONS

Exercise interventions with or without educational interventions that can be applied in the workplace have the potential to prevent LBP.

WITHDRAWN: Lumbar supports for prevention and treatment of low-back pain

BACKGROUND

Lumbar supports are used in the treatment of low back pain patients to make the impairment and disability vanish or decrease. Lumbar supports are also used to prevent the onset of low back pain (primary prevention) or to prevent recurrences of a low back pain episode (secondary prevention).

OBJECTIVES

The objective of this systematic review was to assess the effects of lumbar supports for prevention and treatment of non-specific low back pain.

SEARCH STRATEGY

We searched the Medline, Cinahl and Current Contents databases and the Cochrane Controlled Trials Register up to September 1999, and the Embase database up to September 1998. We also screened references given in relevant reviews and identified controlled trials, and used Science Citation Index to identify additional controlled trials.

SELECTION CRITERIA

Controlled clinical trials that reported on any type of lumbar supports as preventive or therapeutic intervention for non-specific low back pain were included.

DATA COLLECTION AND ANALYSIS

One author extracted data from the trials considering characteristics of the study population, characteristics of the interventions and the final results for each outcome measure. The author compared these findings to data regarding the same characteristics of the same studies published already in other reviews. The methodological quality was independently assessed by two authors. Because it was not possible to perform a quantitative analysis, a qualitative meta-analysis was performed in which the strength of evidence on the effectiveness of lumbar supports was classified as being strong, moderate, limited or conflicting, and no evidence.

MAIN RESULTS

Five randomized and two nonrandomized controlled preventive trials and six randomized therapeutic trials were included in our review. Overall the methodological quality of the studies included in our review was rather low. Only four of the thirteen studies scored positive on 50% or more of the the internal validity items. There was moderate evidence that for primary prevention lumbar supports are not more effective than other types of treatment or no intervention. No evidence was found on the effectiveness of lumbar supports for secondary prevention. The systematic review of therapeutic trials showed that there is limited evidence that lumbar supports are more effective than no treatment, while it is still unclear if lumbar supports are more effective than other interventions for treatment of low back pain.

AUTHORS' CONCLUSIONS

There is still a need for high quality randomised trials on the effectiveness of lumbar supports. One of the most essential issues to tackle in these future trials seems to be the realisation of an adequate compliance.

The consequences of job stress for nurses' health: time for a check-up

The processes and outcomes of nurses' work are described extensively in studies about patient care, nursing education and training, job satisfaction, health care quality and management, and organizational behavior. These studies evaluate the relationship between nurses' behavior and organizational health (ie, productivity) or between nurses' behavior and patient health (ie, medical error). Fewer studies probe the association between the nature of nursing work and the status of nurses' health despite the logical connection between how well nurses feel and how well they perform, or even, whether they discontinue working altogether for health reasons. Yet, for many nurses working in today's health care environment, work is a stressful part of their lives. This article explores the connections between stressful work and nurses' health, especially given the restructuring of their work in the current health care system. The working conditions that give rise to stress and the potential health consequences from it are well described in the general stress literature and summarized herein. Moreover, studies about nurses' work and nurses' health are discussed in light of the limitations for connecting job stress to job changes or health outcomes over time. Current approaches for dealing with nurses' stress, such as the attraction to "Magnetism", may inadvertently impede progress in this area. Recommendations for the future are included.

Comparison of cumulative low back loads of caregivers when transferring patients using overhead and floor mechanical lifting devices

BACKGROUND

Mechanical lifting devices are recommended as an important intervention for reducing lifting injuries among nursing personnel; previous research suggests that spinal loads are not minimized for all device types. The purpose of this study was to describe the spinal loading pattern while performing a bed to chair transfer comparing Overhead and Floor powered lifting devices.

METHODS

A Latin Square design was employed to evaluate five lifting devices while performing a heavy patient transfer. The primary outcomes were spinal compression, and anterior shear (across median and cumulative loading conditions), and ratings of perceived exertion. An inverse dynamic approach was used to calculate the net joint forces and moments about the L5/S1 spinal level. The transfer was partitioned into seven distinct phases for biomechanical analysis.

FINDINGS

The proportion of time spent and the mean loads sustained in each phase of the transfer were described. Significant differences in loads were observed between the differing lifting devices, particularly during the transport phases for the Overhead devices. Nurse subjects consistently ranked Overhead lifting devices as most preferred.

INTERPRETATION

A large proportion of the time to complete the transfer and cumulative loads occurred during phases that involved only the sling and not the mechanical component of the device. Overhead lifting devices were shown to have lower spinal loads during the transport phases. The results of this study have implications for the use and selection of mechanical lifting devices as part of a strategy to reduce back injuries.

[Is it possible to sustain health promotion programs in private companies? The case of four Quebec private companies of blue collar workers]

OBJECTIVE

Sustained health promotion programmes in the workplace (HPPW) continues to be a public health challenge. This article presents an evaluation of the implementation and sustainability of such programmes in private blue-collar companies in Quebec to shed light on issues specific to this type of setting.

METHOD

A multiple case (4 sites), longitudinal (7 years) and interpretive study method was used. The interpretation framework considered that the implementation and sustainability of HPPW in companies are the result of organizational learning in health promotion, determined by the strategies of individuals in a position of control who shape the decisional processes related to these programmes.

RESULTS

After seven years of observation, two of the four sites had continued their HPPW, although these programmes were no longer applied within these companies. The health promotion organizational learning processes in both sites were defined according to targeted organizational purposes set by the decision-makers who supported HPPW. However, these gains were largely lost when HPPW were no longer retained as a component of their organizational development strategy.

DISCUSSION

The organizational conditions that are conducive to HPPW are difficult to put together and sustain in companies like those in our study. Businesses implement these programmes mainly for the organizational benefits they expect to reap in the short term, whereas improvement in the health of workers in the longer term is not a priority.

Disabling and fatal occupational claim rates, risks, and costs in the Oregon construction industry 1990-1997

This study estimated injury and illness rates, risk factors, and costs associated with construction work in Oregon from 1990-1997 using all accepted workers' compensation claims by Oregon construction employees (N = 20,680). Claim rates and risk estimates were estimated using a baseline calculated from Current Population Survey data of the Oregon workforce. The average annual rate of lost-time claims was 3.5 per 100 workers. More than 50% of claims were by workers under 35 years and with less than 1 year of tenure. The majority of claimants (96.1%) were male. There were 52 total fatalities reported over the period examined, representing an average annual death rate of 8.5 per 100,000 construction workers. Average claim cost was $10,084 and mean indemnity time was 57.3 days. Structural metal workers had the highest average days of indemnity of all workers (72. 1), highest average costs per claim ($16,472), and highest odds ratio of injury of all occupations examined. Sprains were the most frequently reported injury type, constituting 46.4% of all claims. The greatest accident risk occurred during the third hour of work. Training interventions should be extensively utilized for inexperienced workers, and prework exercises could potentially reduce injury frequency and severity.

Efficacité des interventions s’adressant à des sujets lombalgiques, du point de vue du retour au travail

BACKGROUND

Return to work is considered as a major effectiveness criterion for interventions dedicated to subacute or chronic low-back-pain sufferers. Moreover, return to work, beyond the economic and social Issues, is regarded more and more as having a therapeutic dimension. This review aims to describe the various interventions which are effective in returning patients to work.

METHODS

The presentation is based on existing reviews supplemented by a selection of recent studies.

RESULTS

"Cognitive-behavioral therapy", "reassurance" and "back exercises" are some suggested approaches. Some of these techniques are geared specifically towards work. Others, such as "back schools" or "multidisciplinary interventions" combine different approaches.

CONCLUSION

Promoting return to work at an appropriate stage (subacute stage) could help low-back-pain sufferers to avoid prolonged disability.

Effectiveness of a worksite intervention to reduce an occupational exposure: the Minnesota wood dust study

OBJECTIVES

This study assessed the effectiveness of an intervention to reduce wood dust, a carcinogen, by approximately 26% in small woodworking businesses.

METHODS

We randomized 48 businesses to an intervention (written recommendations, technical assistance, and worker training) or comparison (written recommendations alone) condition. Changes from baseline in dust concentration, dust control methods, and worker behavior were compared between the groups 1 year later.

RESULTS

At follow-up, workers in intervention relative to comparison businesses reported greater awareness, increases in stage of readiness, and behavioral changes consistent with dust control. The median dust concentration change in the intervention group from baseline to follow-up was 10.4% (95% confidence interval = -28.8%, 12.7%) lower than the change in comparison businesses.

CONCLUSIONS

We attribute the smaller-than-expected reduction in wood dust to the challenge of conducting rigorous intervention effectiveness research in occupational settings.

Do workplace interventions prevent low-back disorders? If so, why?: a methodologic commentary

The demand for workplace interventions to prevent low-back disorders has increased in recent years. At the same time, a crisis in the literature has become apparent: there are conflicting reports on whether or not these interventions work. With the aim of understanding the reason for the dissension in the literature, six studies were selected for close examination. These were studies of interventions based on differing principles, i.e. a change in organizational ethos to promote back safety, back belt use, the introduction of ergonomic devices, and back-strengthening exercises. If the studies are taken at face value, any of the interventions, regardless of type, has a tremendous effect. Methodological problems inherent in these studies may provide a clue to why essentially different interventions were found to be consistently successful. Study design quality has long been noted to exert a particular influence on the evaluation of outcomes: the quality of the study design is often inversely related to reported outcomes. Of the six studies selected for examination, four did not include a contemporaneous control group, five did not randomly assign subjects to test and control groups, and none included a placebo group. Given these research designs, variables other than those tested by the studies may have produced the reported results. These variables include 'beliefs of the intervention providers' and 'coalescence of the work group', both of which are discussed. Two approaches, the pragmatic and the explanatory, may be used to study workplace interventions to prevent low-back disorders. Most of the examined studies are pragmatically oriented. Having dealt with study design problems expeditiously, these studies may be characterized as more immediately responsive to the demand to evaluate workplace interventions than explanatory studies. On the other hand, explanatory studies, most notably associated with randomized clinical trials in medicine, are more rigorous. Enough pragmatically oriented studies have been conducted to suggest that workplace interventions may have an effect on low-back disorders. More conclusive explanatory studies may now be conducted.