Lifting Belts: A Review

This article reviews and evaluates the literature related to the effectiveness of protective restraints on abdominal strength, lower back injuries, and workers’ discomfort. The studies indicate that back belts have potential disadvantages as well as advantages. Belts seem to reduce lifting stress. They may, however, lead to a false sense of security while being worn and may also weaken the body, so injury occurs when they are not being worn. There also seems to be comfort problems with some belts. More scientific research is needed before any conclusions can be drawn about positive, negative, or long-term effects of lifting belts.     

Three-Dimensional Lifting Model For Non-Homogeneous Loads

A 3-dimensional model and analysis methodology is suggested for treating lifting tasks when unbalanced loads are involved. The paper describes the biomechanical equations that are coupled with the worker’s posture geometry, to address a practical problem of non-symmetric lifting. The analysis has a dominant biomechanical modeling scope, as it contains a breakdown of the internal lifting forces resulting from posture and external loads acting on the body. The load model represents the acting forces due to unbalanced lifting, which is commonly found in industrial situations. The suggested model allows the user to simulate the influence of the practical load distribution, aiding safe design of a lifting job.     

Effects of Manual Handling,Posture, and Whole Body Vibrations on Low-Back Pain

To determine the effect of occupational stress on low-back pain (LBP), a cross-sectional study has been carried out, by interviews, on workers exposed to 3 stresses: manual handling (MH, 82 women and 264 men), whole body vibrations (WBV, 274 men), and static postures (278 women). Anthropometric data, occupational stress, LBP severity and frequency, and a psychological evaluation of these groups were compared to those of a control population of 208 workers (104 men and 104 women).

The results show that 30% of the population had never suffered from LBP. Age and the body mass index of the workers were the parameters most closely associated with LBP. Women involved in MH had higher frequency and severity of LBP than their reference population. Men involved in MH or exposed to WBV had higher frequency of painful episodes than their reference population. Workers exposed to one of the stresses were on sick leave for LBP more often, and for longer periods, than workers in the reference group. The results show that individual factors are often decisive in the onset of LBP. Nevertheless, in the more serious LBP cases, occupational stress is an aggravating factor for LBP and its consequences.     

Manual Handling Injuries in Health Care Workers

Nursing aides are particularly susceptible to manual handling injuries because they have the primary responsibility for heavy lifting. The aim of this study was to determine why a specific group of nursing aides have the highest manual handling injury rate in their hospital. The study investigated the adequacy of the manual handling training program, knowledge of manual handling, mechanical aid availability, and use of mechanical aids. Results indicated that the nursing aides’ manual handling knowledge was adequate but that they rarely used mechanical aids. This lack of use of aids was in part due to an over-reliance on their own strength and abilities. This may have been due to a lack of suitable mechanical aids on the wards or a lack of familiarity with the available aids. This study suggests that neither training alone nor the purchase of equipment alone is likely to resolve manual handling problems.     

Lower back pain and its association with whole-body vibration and manual materials handling among commercial drivers in Sabah

A cross-sectional study was undertaken to determine the prevalence of lower back pain (LBP) and its association with whole-body vibration (WBV) and manual materials handling (MMH). We studied 110 commercial vehicle drivers using a self-administered questionnaire and the VI-400Pro human vibration monitor. Prevalence of LBP was 66.4%. The percentage of drivers who had frequent manual handling of heavy loads was 45.5% and those who handled heavy loads in awkward postures accounted for 86.4%. Daily vibration A(8) averaged on the z axis was 0.25 (0.06) m·s^?2 and at vector sum was 0.29 (0.07) m·s^?2. Daily vibration exposures on the z axis, frequent manual handling of heavy loads and awkward posture during MMH were significantly associated with LBP. Drivers who are exposed to WBV and frequently handle heavy loads manually and with awkward postures probably have more LBP than drivers who are exposed to only one of these risk factors.     

NIOSH手工提举方程在缸盖搬运中的应用

为了平衡操作人员的精力和体力,在保证人安全的前提下,提高生产力。采用NIOSH（National Institute of Occupational Safety and Health）提举方程对机加工车间缸盖搬运上线工位进行人机工程安全评估,通过对操作工作业的水平距离（H）、垂直距离（V）、提升距离（D）以及频率（F）进行研究,并对修订版NIOSH提举方程的重量常量与高度系数进行了修正。结果表明,经过合理调整四大参数,可在不设起吊、机器人等设备的情况下,保证人的身心健康,节约成本,提高人的工作效能。     

An Evaluation of the NIOSH Lifting Equation: A Psychophysical and Biomechanical Investigation

Using the results of psychophysical and biomechanical experiments, NIOSH (National Institute for Occupational Safety and Health) Recommended Weight Limit (RWL), the Lifting Index (LI), the form of the asymmetry multiplier, and the criterion for compression force were investigated. Analysis of the results indicated a significant difference between the NIOSH RWL and the reported Maximum Acceptable Weight of Lift (MAWL). Contrary to the NIOSH lifting equation, the form of the asymmetry multiplier was found to be non-linear. The overall average of peak compression force on the L5/S1 was 3685 N. Fifty-eight percent of all compression forces reported in the biomechanical experiment were found to exceed the suggested 3400 N set by NIOSH guidelines. These results support previous research findings on the validity of NIOSH guidelines.     

手工电弧焊接防触电措施

从电焊机的使用中的常见问题诸如电源的连接、设备的包养、防护的措施等方面告诉人们如何去避免危险的放生。对实际的现场作业的安全防护具有现实的指导意义。     

The Effect of Protective Gloves on Manual Dexterity in the Cold Environments

This article presents a study on the effect of different protective gloves (which are commercially available and commonly used in the cold) on manual dexterity in cold environments. The experiments compared statistically four different types of gloves and two different types of gloving (outer or double) at +19 °C and -10 °C. Performance was determined both objectively and subjectively using two manual dexterity tasks: bolt-nut and pick-up tasks. The response measured was the time of performing each task. Statistical analysis showed that all independent factors such as glove type, participant, object size, and temperature had significant effects on the hand cooling reaction. A significant difference in the performance between the gloves was found in the bolt-nut task. It was also found that outer-inner combination gloving may be an approach to use for precision tasks.     

Load Acceleration and Footstep Strategies in Asymmetrical Lifting and Lowering

Accelerated execution effects for lifting and lowering a 12-kg box using two footstep strategies associated with experienced workers were studied. Eight healthy male participants performed a normal and an accelerated execution of a lifting task and a lowering task, using a minimal feet displacement strategy (oblique-step) and a strategy with a step (crossed-step). It was hypothesized that the accelerated executions, as compared to the normal executions, would have a different effect on L5/S1 resultant moment, body posture, and other kinematic variables. A tridimensional dynamic rigid body model was used to compute L5/S1 resultant moments. Results showed that the accelerated condition did not reduce body asymmetry of posture, but it reduced the length of the path of the global center of gravity and the duration of the supporting phase of the box, and it did not significantly affect L5/S1 maximal resultant moments for lifting but increased them for lowering. These results indicate that the net work production for accelerated strategies might be smaller, which may represent an economy of energy. Furthermore, the results showed that the use of an accelerated strategy for lowering should be avoided.     

Pushing and pulling: an assessment tool for occupational health and safety practitioners

A tool has been developed for supporting practitioners when assessing manual pushing and pulling operations based on an initiative by two global companies in the manufacturing industry. The aim of the tool is to support occupational health and safety practitioners in risk assessment and risk management of pushing and pulling operations in the manufacturing and logistics industries. The tool is based on a nine-multiplier equation that includes a wide range of factors affecting an operator’s health risk and capacity in pushing and pulling. These multipliers are based on psychophysical, physiological and biomechanical studies in combination with judgments from an expert group consisting of senior researchers and ergonomists. In order to consider usability, more than 50 occupational health and safety practitioners (e.g., ergonomists, managers, safety representatives and production personnel) participated in the development of the tool. An evaluation by 22 ergonomists supports that the push/pull tool is user friendly in general.     

Low Back Muscle Activity in an Automobile Seat with a Lumbar Massage System

This investigation was conducted to determine the effects of a massaging lumbar support system on low back muscle activity. The apparatus included a luxury-level automobile seat, six 10-mm diameter bipolar surface electrodes, an amplifier, an analog-to-digital conversion board, data acquisition software, and a personal computer. Six experimental conditions, each involving a variation of massage time, were considered. The dependent variable was the change in the root mean square variation of the EMG signal. One minute of lumbar massage every 5 min was found to have a beneficial effect on low back muscle activity (as compared to no massage). This may prove to be an extremely important result in the quest to combat low back pain attributable to automobile seating.     

机械制造业中事故原因的分析与控制

目前社会安全生产事故频频发生,形势非常严峻.在机械制造业中,如何对安全生产事故进行有效的预防,保持良好的安全生产秩序,这对安全生产,维护安全稳定是至关重要的.用系统分析的方法,对机械制造过程中,人-机器-环境这一封闭的系统,每一个环节进行了分析,从而总结出了预防事故的方法和原则,对实际的生产有重要的指导意义.     

Influence of trunk muscle activity and stability in front and back holding

Purpose. A tandem carrying style is often used in the workplace, but carrying approaches are different for two people because of the holding load in the tandem posture. To understand these carrying styles, this study aimed to investigate the patterns of muscle activity and stability of the trunk influenced by front and back holding of a heavy load. Methods. Electromyography data of eight trunk and two hip muscles, as well as displacements of the trunk, were recorded for analysis while subjects stood statically holding a handle in the front and back of the body with and without load. Results. Without load, muscle activities during front holding mirrored those during back holding. With load, greater muscle activities were observed in the dorsal muscles of the trunk and lesser activities were noted in the ventral muscles in the two holding styles. More frequencies of trunk oscillations occurred in front holding with and without load. Conclusions. The results revealed that back holding of load created more stability of the upper body, whereas front holding resulted in more instability of the trunk.     

A Comparative Ergonomics Postural Assessment of Potters and Sculptors in the Unorganized Sector in West Bengal,India

Potters and sculptors perform their work in very awkward postures. The purpose of this study was to analyse these postures. The modified Nordic questionnaire was used to analyse musculoskeletal discomfort. Rapid entire body assessment (REBA) and rapid upper limb assessment (RULA) were used to evaluate the subjects’ postures. There were no significant differences between times of discomfort and the group of subjects. However, there were significant differences in discomfort in different body parts. The analysis indicated that various body postures were harmful to the subjects and that there were profound deviations from natural curvature of various body parts due to awkward body postures. Ergonomics intervention was required to improve the quality of life.     

Risk Factors to Musculoskeletal Disorders and Anthropometric Measurements of Filipino Manufacturing Workers

This study looked into the risk factors to musculoskeletal disorders and established anthropometric measurements of Filipino workers in 29 manufacturing industries. Anthropometric measurements of 1,805 workers were taken, and 495 workers were surveyed. Limitation of motion was found in 0.8% of the respondents, affectation in activities of daily living was seen in 1.6% and 3.2% felt discomfort in the head and neck. Upper trunk and low back pain was experienced by 23.8%. Odds ratio results (p = .05) showed that it is 29 times likely for workers to develop low back pain when they stand for 2-8 hrs a day than when they sit all the time. Anthropometry can be used for the design ofworkstations and work furniture.     

A detailed analysis of musculoskeletal disorder risk factors among Japanese nurses

INTRODUCTION: Although Musculoskeletal Disorders (MSD) represent a common occupational problem, few epidemiological studies have investigated MSD risk factors among Asian nurses, particularly those in Japan. METHOD: We administered a modified Japanese-language version of the Standardized Nordic Questionnaire to 1,162 nurses from a large teaching hospital. MSD categories focused on the neck, shoulder, upper back, and lower back regions. RESULTS: A total of 844 completed questionnaires were analyzed (response rate: 72.6%). The 12-month period-prevalence of MSD at any body site was 85.5%. MSD was most commonly reported at the shoulder (71.9%), followed by the lower back (71.3%), neck (54.7%), and upper back (33.9%). Alcohol consumption, tobacco smoking, and having children were shown to be significant risk factors, with adjusted Odds Ratios of 1.87 (95%CI: 1.17-2.96), 2.45 (95%CI: 1.43-4.35), and 2.53 (95%CI: 1.32-4.91), respectively. Workplace risk factors included manually handling patients (OR: 2.07 to 11.97) and undertaking physically laborious work (OR: 2.09 to 2.76). Nurses reporting pre-menstrual tension were 1.66 and 1.94 times more likely to suffer from lower back and upper back MSD, respectively. High mental pressure was also identified as a significant risk factor for MSD of the neck (OR: 1.53) and shoulder (OR: 2.07). IMPACT ON INDUSTRY: The complex nature of MSD risk factors identified during this study suggests that remediation strategies which focus only on manual handling tasks would probably be suboptimal in reducing MSD among nurses. Therefore, to help alleviate their considerable MSD burden, a greater emphasis will need to be placed on job satisfaction, work organization, and occupational stress, as well as the more traditional hazard reduction strategies such as manual handling, work tasks, and other occupational factors.     

Causation of Severe and Fatal Accidents in the Manufacturing Sector

The main purpose of this paper is to identify the most frequent causes of accidents in the manufacturing sector in Andalusia, Spain, to help safety practitioners in the task of prioritizing preventive actions. Official accident investigation reports are analyzed. A causation pattern is identified with the proportion of causes of each of the different possible groups of causes. We found evidence of a differential causation between slight and non-slight accidents. We have also found significant differences in accident causation depending on the mechanism of the accident. These results can be used to prioritize preventive actions to combat the most likely causes of each accident mechanism. We have also done research on the associations of certain latent causes with specific active (immediate) causes. These relationships show how organizational and safety management can contribute to the prevention of active failures.     

Structural equation modelling of lower back pain due to whole-body vibration exposure in the construction industry

Whole-body vibration (WBV) exposure is a health hazard among workers, causing lower back pain (LBP) in the construction industry. This study examines key factors affecting LBP due to WBV exposure using exploratory factor analysis and structural equation modelling. The results confirm five key factors (equipment, job related, organizational, personal, social context) with their 17 associated items. The organizational factor is found the most important, as it influences the other four factors. The results also show that appropriate seat type, specific training programme, job rotation, workers’ satisfaction and workers’ physical condition are crucial in reducing LBP due to WBV exposure. Moreover, provision of new machines without proper training and good working condition might not help reduce LBP due to WBV exposure. The results help the construction companies to better understand key factors affecting LBP due to WBV exposure, and to plan for a better health improvement programme.