Hum Factors

ObjectiveTo evaluate the impact of the revised National Institute for Occupational Safety and Health lifting equation (RNLE).BackgroundThe RNLE has been used extensively as a risk assessment method for prevention of low back pain (LBP). However, the impact of the RNLE has not been documented.MethodsA systematic review of the literature on the RNLE was conducted. The review consisted of three parts: characterization of the RNLE publications; assessment of the impact of the RNLE; and evaluation of the influences of the RNLE on ergonomic standards. The literature for assessing the impact was categorized into four research areas: methodology, laboratory, field and risk assessment studies using the Lifting Index (LI) or Composite LI (CLI), both of which are the products of the RNLE.ResultsThe impact of the RNLE has been both widespread and influential. We found 24 studies that examined the criteria used to define lifting capacity used by the RNLE, 28 studies that compared risk assessment methods for identifying LBP, 23 studies that found the RNLE useful in identifying the risk of LBP with different work populations, and 13 studies on the relationship between LI/CLI and LBP outcomes. We also found evidence on the adoption of the RNLE as an ergonomic standard for use by various local, state, and international entities.ConclusionThe review found 13 studies that link LI/CLI to adverse LBP outcomes. These studies showed a positive relationship between LI/CLI metrics and the severity of LBP outcomes.CC999999/Intramural CDC HHS/United States2017-08-01T00:00:00Z26822795PMC499182

Design and balancing of assembly lines that minimize ergonomic risk

Minimización del Riesgo ergonómico de la línea de motores de Nissan-BCN en función del número de estaciones de trabajo.In this paper, an assessment system of the ergonomic hazards existing in the workstations of an assembly line is provided. A mathematic model to solve the assembly line balancing problem is developed with the aim of minimizing the ergonomic risk that exists in an assembly line by taking into account the number of workstations and a set of temporal and spatial restrictions. This model has been applied, by means of a computational experiment, in a problem taken from a case study of Nissan’s engine plant in Barcelona. The experiment measures the impact that the increase in the number of workstations causes on the improvement of the ergonomic quality of such workplaces and on the reduction of the ergonomic risk.Preprin

Cardiovascular and Psychophysical Response to Repetitive Lifting Tasks in Women

BACKGROUND: Understanding the cardiovascular and psychophysical demands of repetitive lifting tasks is important in job design strategies. This study determined the cardiovascular (oxygen consumption (VO) and heart rate (HR) and psychophysical response to repetitive lifting tasks in women. METHODS: Ten female (age 27 ± 5 yrs) participants transferred 11.4, 15.9, and 20.5 kg weights back and forth from a rung 40.6 cm high to a rung 156.2 cm high. Rungs were 195.6 cm apart horizontally. Three, 10 minute bouts (1 = 11.4 kg; 2 = 15.9 kg; 3 = 20.5 kg) were performed at 6 lifts per minute. Cardiovascular and psychophysical (rating of perceived exertion, RPE) parameters were monitored throughout the bouts. VOmax and HRmax were determined via a maximal treadmill test. RESULTS: VO, HR, and RPE were significantly different between each work bout (p \u3c 0.01), with each outcome variable increasing as load increased. VOmax and HRmax equaled 46.5 ± 7.5 mL·kg·min and 191 ± 11 bpm, respectively. Work at 11.4 kg was performed at 38% VOmax and 63% HRmax; at 15.9 kg at 41% VOmax and 72% HRmax; and at 20.5 kg at 49% VOmax and 81% HRmax. RPE at 11.4, 15.9, and 20.5 kgs were: 8.4 ± 1.6, 11.4 ± 1.9, and 15.0 ± 2.2. CONCLUSION: During these repetitive lifting tasks, metabolic cost and perceived exertion increased with weight lifted; average work intensity ranged from 63 to 81% of HRmax and 38 to 49% of VOmax. Results have important implications in relation to job pacing and design, and worksite health promotion strategies aimed at reducing work place injury

Hum Factors

ObjectiveThe National Institute for Occupational Safety and Health (NIOSH) Revised Lifting Equation (RNLE) was adapted to derive recommended weight limits (RWLs) for pregnant workers and to develop corresponding guidelines for clinicians.BackgroundIn the past three decades there has been a large increase in the number of women employed outside the home and remaining in the workforce during pregnancy. Practical authoritative guidelines based on accumulated evidence are needed to inform allowable work activity levels for healthy pregnant workers.MethodEmpirically based lifting criteria established by NIOSH to reduce the risk of overexertion injuries in the general U.S. working population were evaluated for application to pregnant workers. Our evaluation included an extensive review of the literature linking occupational lifting to maternal and fetal health. Decision logic and supporting literature are presented, along with computational details.ResultsProvisional RWLs for pregnant workers were derived from the RNLE, along with guidelines for clinicians. The guidelines advise against pregnant workers lifting below midshin and overhead.ConclusionBased on our review of the available evidence, we present lifting thresholds that most pregnant workers with uncomplicated pregnancies should be able to perform without increased risk of adverse maternal and fetal health consequences. Except for restrictions involving lifting from the floor and overhead, the provisional guidelines presented are compatible with NIOSH lifting recommendations adopted in the early 1990s for the general working population.ApplicationImplementation of these provisional guidelines could protect millions of female workers in the work-place from fetal and maternal lifting-related health problems.CC999999/Intramural CDC HHS/United States2015-10-15T00:00:00Z24669554PMC4606868vault:1332

Evaluation of a Safe Patient Handling Program

Purpose : The purpose of this project was to evaluate the effectiveness of implementing a comprehensive Safe Patient Handling (SPH) Program system wide in a large healthcare organization relative to injury severity and organizational cost. Background : Extensive review of the literature reveals clear evidence that healthcare workers who participate in patient handling activities continue to be at a very high risk for occupational musculoskeletal injuries. Workers employed up to one year, and those employed greater than ten years within the institution studied were noted to have higher rates of injures that were more severe and more costly to the organization. Methods : Implementation of a comprehensive SPH program was implemented in 2010 and all direct patient caregivers were trained. The sample consisted of new hires (n=89) and long term hires (n=144) identified via aggregate data from data bases owned by the institution. Data were analyzed on the Statistical Package for the Social Sciences (SPSS) program. Mean differences in the severity of injury and cost of injury between pre and post-training periods were analyzed via independent samples t-tests. Chi-square was used to identify whether there was a significant difference in the frequency of injuries between the pre and post-training periods. Results : Results indicated that the average injury severity during the pre-test period was significantly higher compared to post-test. No significant differences were found related to cost or frequency of injury between pre and post-test. Discussion : Issues related to the practical significance of the results and challenges due to the small sample size are discussed

The sensor-based biomechanical risk assessment at the base of the need for revising of standards for human ergonomics

Due to the epochal changes introduced by “Industry 4.0”, it is getting harder to apply the varying approaches for biomechanical risk assessment of manual handling tasks used to prevent work-related musculoskeletal disorders (WMDs) considered within the International Standards for ergonomics. In fact, the innovative human–robot collaboration (HRC) systems are widening the number of work motor tasks that cannot be assessed. On the other hand, new sensor-based tools for biomechanical risk assessment could be used for both quantitative “direct instrumental evaluations” and “rating of standard methods”, allowing certain improvements over traditional methods. In this light, this Letter aims at detecting the need for revising the standards for human ergonomics and biomechanical risk assessment by analyzing the WMDs prevalence and incidence; additionally, the strengths and weaknesses of traditional methods listed within the International Standards for manual handling activities and the next challenges needed for their revision are considered. As a representative example, the discussion is referred to the lifting of heavy loads where the revision should include the use of sensor-based tools for biomechanical risk assessment during lifting performed with the use of exoskeletons, by more than one person (team lifting) and when the traditional methods cannot be applied. The wearability of sensing and feedback sensors in addition to human augmentation technologies allows for increasing workers’ awareness about possible risks and enhance the effectiveness and safety during the execution of in many manual handling activities

Biomechanical Modelling of Manual Material Handling Tasks: A Comprehensive Review

AbstractIn a developing country like India where industrial tasks are labour-intensive, involving Manual Material Handling (MMH) in many situations; workload measurement in terms of Newtonian anthropometry and physiological parameters is important to identify unduly heavy tasks, to evaluate traditional work methods, and to arrive at more efficient methods of work. In jobs which require prolonged manual labour like construction jobs, assessment of cardiovascular capacity may be used to determine a worker's level of fitness for work. To tackle the issues as mentioned, various approaches, such as biomechanical, physiological and physical evaluations may be used for proper quantification and minimization of risks of Musculoskeletal Disorders (MSDs) associated with different types of material handling tasks in order to reduce fatigue and physical stress. Among all evaluations, biomechanical evaluation deals with the study of the physical interaction of workers with their tools, machines, and materials so as to enhance the worker's performance while minimizing the risk of MSDs. In this context, studies of various biomechanical models (static and dynamic) are required to be studied. In this paper, a comprehensive review of the concepts of static and dynamic models as applicable for MMH task is presented. Starting with various types of static and dynamic models, the issues on occupational risk assessment related to various manual handling tasks are discussed progressively. The distinctiveness of the models are highlighted. Finally, based on the critical appraisal of the existing approaches, future research directions on various models of biomechanical evaluation are delineated

Am J Obstet Gynecol

Empirically based lifting criteria established by the National Institute for Occupational Safety and Health (NIOSH) to reduce the risk of overexertion injuries in the general US working population were evaluated for application to pregnant workers. This report proposes criteria to guide decisions by medical providers about permissible weights for lifting tasks performed at work over the course of an uncomplicated pregnancy. Our evaluation included an extensive review of the literature linking occupational lifting to maternal and fetal health. Although it has been 29 years since the American Medical Association's Council on Scientific Affairs published its report on the Effects of Pregnancy on Work Performance, these guidelines continue to influence clinical decisions and workplace policies. Provisional clinical guidelines derived from the NIOSH lifting criteria that account for recent evidence for maternal and fetal health are presented and aim to improve the standard of care for pregnant workers.20132015-08-28T00:00:00ZCC999999/Intramural CDC HHS/United States23467051PMC4552317864

Reducing low back pain and disability in mining

"This report was written in an effort to provide better control measures for low back pain (LBP) and low back disability in the mining industry. There are numerous factors associated with development of LBP, many of which can be effectively controlled while some cannot. Better job design is promoted as the best method of reducing cases of LBP and can also reduce the disability (i.e., lost time from work) associated with LBP when it happens. The report draws attention to what is currently known about LBP, what the causes are thought to be, and discusses recent back injury trends in the mining industry. Research describing unique physical demands in mining, such as the capabilities and limitations of working in awkward postures, is also presented. Methods that can be used to prevent initial LBP episodes are provided, including facilities design and layout for materials and supplies, use of mechanicalassist devices, improved design of lifting tasks, and better seat design. Methods of reducing the disability associated with LBP (including workplace design, proactive return-to-work efforts, communication, and management commitment) are also discussed. The report concludes that control of LBP and disability in mining requires a comprehensive approach to limit the repetitive loading that can occur on the low back due to manual materials-handling tasks and exposure to whole-body vibration (WBV). Specific recommendations include the following: 1. Successful LBP prevention efforts require a proactive program that has strong management commitment and incorporates employee involvement. 2. More efficient supply handling systems and use of mechanical-assist devices can greatly reduce exposure to hazardous lifting tasks. 3. Lifting tasks should be designed to minimize low back stress. Tools to evaluate and redesign lifting tasks are presented. 4. Improved seat design can reduce exposure to WBV and improve posture, leading to reduced LBP risk. 5. The disability associated with LBP can be reduced. Getting the worker back on the job as quickly as possible is in the interest of everyone involved." - NIOSHTIC-2by Sean Gallagher.Includes bibliographical references (p. 67-75)