Preliminary Ergonomic Evaluation of Barn Tasks in Intensive Swine Production

ABSTRACT

This exploratory pilot study analyses musculoskeletal symptoms and working exposures of intensive pig barn tasks. Methods included a questionnaire phase to gather information about workers’ symptoms and video analysis to assess exposures during typical production tasks. Ninety-two percent of workers reported symptoms in the last 12 months in any body part; 58% reported interruption of work activities in the last 12 months. The task “moving dead pigs” exceeded 3400 N during 6 of 18 observations. Frequency of hand gripping and trunk bending >45 degrees were moderate to high in many tasks. These biomechanical exposures suggest a need for further study, particularly on interventions to limit bending, lifting, and repetitive gripping.     

Musculoskeletal Discorders in Industrial Workers of Delhi

Abstract

To study the musculoskeletal disorders in industrial workers in Delhi, 631 workers from 60 factories representing small and medium-sized enterprises located in Delhi were interviewed. Many (59.4%) of the workers had musculoskeletal disorders. Tailors, those working near furnaces, cooks, workers in buffing, checking and assembly work, and those working with chemicals had the most joint complaints. Cervical pain was more frequent in tailoring and packing work, whereas lumbar pain was more common in buffing, operators working on presses, those using hand and power tools, and those lifting heavy manual loads. Contract workers had less musculoskeletal morbidity than regular and temporary workers. Skilled workers also had less morbidity. Workers experiencing more job satisfaction reported fewer musculoskeletal disorders. The high prevalence of musculoskeletal disorders in workers needs urgent attention from the health and labor sectors. An ergonomic approach to prevention should be considered. The current manual load handling limits prescribed in the Indian Factory Rules potentially expose workers to back stress.It is also inappropriate to have separate load-lifting limits for men and women. Research is urgently required to determine the safe load handling limits for the Indian working population based on ergonomic principles. Until internationally acceptable safe limits are established, back pain should be a notifiable diseasein India.     

A comparison of isometric strength and dynamic lifting capacity in men with work-related low back injuries

Job classification, return to work status, and job placement are determined by the results of lifting capacity tests. Lifting capacity is often assessed by maximum static or dynamic physical exertions. The purpose of this study was to compare maximum isometric lifting strength with maximum dynamic lifting capacity in subjects with work-related low back injury. Twenty-seven men performed five dynamic lifting tasks and two isometric strength tests. The mean Pearson product-moment correlation between maximum isometric lifting strength measurements and maximum dynamic lifting capacity measurements was .51 with a range of .30–.73. The results indicate low to moderate associations between isometric strength measurements and lifting capacity suggesting that estimates of functional lifting capacity should not be based on static measurements alone. Dynamic lift tests are often a better simulation of the task being assessed and may be more appropriate for a back-injured population.     

Effects of work and rest on upper extremity signs and symptoms of workers performing repetitive tasks

The temporal relationship between work and signs and symptoms of upper extremity musculoskeletal disorders among workers at risk is relatively unexplored. The study focused on changes in upper extremity circumference, volume, sensory threshold, and reported symptoms after work and rest. All workers (N=50) performed a repetitive poultry processing task and had exhibited upper extremity signs and symptoms in baseline testing prior to this study. These workers manifested significantly increased upper extremity circumference following a period of rest, with circumferences decreasing during work. Upper extremity volume and reported swelling also decreased during work. Reports of tenderness were significantly greater after work than after rest, while reports of pain were greatest after a short rest interval. Results show that the signs and symptoms observed in these workers were manifestations of occupational cumulative trauma and that further study of the relationship between work and signs and symptoms is needed.     

Reduction of Acute Low Back Injuries by Use of Back Supports

Abstract

The objective of this study was to determine the effect of a change in back-support-use policy on the occurrence of work related low back injuries among a large cohort of employees in the retail-trade home improvement industry. Working hours of exposure, back support use, and intensity of materials-lifting requirements were collected from 1989 through 1994. Records of injury-related claims were reviewed for all documented injuries to the lower back among members of the cohort during the same period. Over 101,000,000 working hours were recorded by nearly 36,000 employees; 2,152 employees reported an acute low back injury occurring during working hours as a first report of episode, with medical-physician diagnosis and acute/abrupt onset. Incidence density rates were calculated for persons wearing and not wearing the back support. Rate ratios and prevented fractions were evaluated. Before implementation of a company-wide back-support policy, the employees had a rate of acute low back injuries of 30.6 per million working hours. After implementation, this rate fell to 20.2 per million working hours, a significant reduction of 34.0%. This effect was seen in both genders, in younger workers and in those aged 55 +, with low levels of lifting as well as high lifting intensities, and in persons with one to two years of employment with the company. The authors conclude that uniform mandatory implementation of a back-support-use policy significantly reduces the incidence of acute low back injuries incurred in the workplace.     

Work-related Musculoskeletal Disorders in Urban Bus Drivers of Hong Kong

Introduction: Work-related musculoskeletal disorders (WMSD) affect workers in many occupations including drivers of large vehicles. Urban bus drivers have been found to have high prevalence rates of back problems in overseas studies. Hong Kong is a densely populated city and has a large number of double-deck buses that constitute a major means of public transportation. The present study aimed at investigating the prevalence and characteristics of WMSD in male and female bus drivers who operate double-deck buses in Hong Kong. Method: Altogether 481 bus drivers (404 males, 77 females) participated in the study that consisted of a questionnaire survey as well as physical assessment. The questionnaire included questions on work, musculoskeletal complaints and perceived occupational risk factors associated with each discomfort. Physical assessment consisted of measurement of lumbar spine mobility, hand grip strength, sit-and-reach test, and observation of standing and sitting postures. Results: The results showed generally the male drivers had longer years of work experience but their daily workloads were similar to the females. On the average drivers worked 9–10 h per day, with 5 days on and 1 day off. Neck, back, shoulder and knee/thigh areas had the highest 12-month prevalence rates ranging from 35% to 60%, and about 90% of the discomfort was related to bus-driving. Occupational factors of prolonged sitting and anthropometric mismatch were perceived to be most related to musculoskeletal discomfort. On physical examination, grip strength was significantly related to neck and shoulder discomfort. Conclusions: The present results showed high prevalence rates of WMSD among bus drivers in Hong Kong which warrants further investigation.     

Effect of an Exercise Programme for the Prevention of Back and Neck Pain in Poultry Slaughterhouse Workers

The objectives of this study were to determine the effectiveness of a programme of prevention exercises conducted in a corporate environment in poultry industry slaughterers suffering from musculoskeletal disorders. Forty workers, 70% female (mean ± SD age: 44.4 ± 8.4 years) were consecutively, in an alternative way, assigned to one of two groups receiving either set of 10 sessions (experimental or control group). The experimental group followed an exercise programme for a period of five weeks and a protocol of home exercises. The control group performed the exercise protocol only at home. The Roland Morris Disability Questionnaire (RMDQ) and the Oswestry Disability Index (ODI) to measure disability, the Visual Analogue Scale (VAS) score and the Pain Drawing to measure pain were used as outcome evaluations. A significant effect of time interaction (all P <0.001 and; F = 40.673; F = 33.907 and F = 25.447) existed for lumbar VAS, RMDQ and ODI immediately after the intervention (all P < 0.006). No significant group effect or group‐by‐time interaction was detected for any of them, which suggests that both groups improved in the same way. This study shows that a programme of prevention exercises may have a positive effect in improving musculoskeletal disorders of slaughterhouse workers. Pain decreased in the lumbar region, and there was an almost significant reduction in disability. Copyright © 2014 John Wiley & Sons, Ltd.     

Work-related musculoskeletal disorders: Comparison of data sources for surveillance

Work-related upper extremity musculoskeletal disorders “associated with repeated trauma” account for more than 60% of all newly reported occupational illness, 332,000 in 1994 according to the U.S. Department of Labor. These numbers do not include, for example, those disorders categorized as “injuries due to overexertion in lifting,” approximately 370,000. Early identification of potential disorders and associated risk factors is needed to reduce these disorders. There are a number of possible methods for conducting surveillance for work-related musculoskeletal disorders (WMDs) based on health outcome: workers' compensation, sickness and accident insurance, OSHA 200 logs, plant medical records, self-administered questionnaires, professional interviews, and physical examinations. In addition, hazard surveillance based on evaluation of job exposures to physical stressors by nonoccupational health personnel is possible. As part of a large labor-management-initiated intervention study to reduce the incidence of WMDs in four automotive plants, we were able to compare the strengths and limitations of each of these surveillance tools. University administered health interviews yielded the highest rate of symptoms; combined physical examinations plus interview (point prevalence) rates were similar to self-administered questionnaires (period prevalence) rates. Plant medical records yielded the lowest rate of WMDs. WMD status on self-administered questionnaire and on physical examination were associated with risk factor exposure scores. This study suggests that symptoms questionnaires associated with risk factor exposure scores. This study suggests that symptoms questionnaires and checklist-based hazard surveillance are feasible within the context of joint labor-management ergonomics programs and are more sensitive indicators of ergonomic problems than pre-existing data sources. Am. J. Ind. Med. 31:600–608, 1997. © 1997 Wiley-Liss, Inc.     

Work-related Musculoskeletal Disorder: An Occupational Disorder of the Goldsmiths in India

Background:

Gold ornament making industries are one of the widespread small-scale industries of India. These industries belong to the unorganized sector of the state. A large number of goldsmiths are working there for prolonged period in cross leg posture at semi-confined workstation.

Objectives:

The aim of this study is to identify Occupational Disorder of the Goldsmiths in India.

Materials and Methods:

In the spresent study, 120 male goldsmiths were randomly selected from the Davangere district of Karnataka. A detailed questionnaire study on discomfort feeling was done by the modified Nordic questionnaire, which considering the information about work nature, job stress and discomfort feeling. The existing workstations were assessed by the measurement of work areas. Analysis of body posture by rapid upper limb assessment was done to evaluate the work stress during their job.

Results:

From the analysis, it was revealed that MSDs were the major problem of the goldsmiths. The activities of the goldsmiths were also highly repetitive. Moreover, the questionnaire study revealed that most of the workers were affected by occupational disorder like pain at neck (80%), shoulder (20%), wrist (45%), and low back (75%) and also eye problem like irritation (30%) and burning sensation (70%). They also perform their job in hazardous postures. It was recorded that the workstations were poorly illuminated (19 Lux) in respect to precision work. Accidents like cut and burn occurred frequently due to the unsafe condition of the workstation.

Conclusions:

From the observation and analysis of the result it was concluded that health of the goldsmiths were highly affected improper body posture and workload. Twisting, bending, and over-reaching are the resultant of poorly designed workstation. These actions force them into a non-neutral position that increases the overall discomfort and pain at the lower back, neck, and shoulders. Moreover, lack of proper illumination at work site also exerts an additional adverse effect on the health of the goldsmiths.     

Stressful psychosocial work environment increases risk for back pain among retail material handlers

BACKGROUND: Back pain is a major source of lost work time. Occupational physical activity only accounts for a fraction of low back pain; therefore, there is growing interest in investigating other possible causes of back pain including the psychosocial work environment. METHODS: Material handlers (N = 6,311) in 160 newly opened stores were interviewed at study entry and approximately 6 months later. Factor analysis was used to reduce the 37 psychosocial questionnaire items to seven distinct factors. RESULTS: After adjusting for history of back problems and work-related lifting, risk of back pain was moderately increased among employees who reported high job intensity demands (odds ratio (OR) = 1.8), job dissatisfaction (OR = 1.7), and high job scheduling demands (OR = 1.6). CONCLUSIONS: Modification of the psychosocial work environment for material handlers in large retail stores may help reduce back pain among employees.     

Physical workload, work intensification, and prevalence of pain in low wage workers: results from a participatory research project with hotel room cleaners in Las Vegas

BACKGROUND: Occupational injury rates among hotel workers exceed the national service sector average. This study assesses the prevalence of back and neck pain, and its associations with physical workload, ergonomic problems, and increasing work demands. METHODS: Nine hundred forty-one unionized hotel room cleaners completed a survey about health and working conditions. Associations between job demands and pain were determined by logistic regression models adjusting for individual characteristics, cumulative work demands, care-taking responsibilities at home, and psychosocial job factors. RESULTS: The 1-month prevalence of severe bodily pain was 47% in general, 43% for neck, 59% for upper back, and 63% for low back pain. Workers in the highest exposure quartiles for physical workload and ergonomic problems were between 3.24 and 5.42 times more likely to report severe pain than workers in the lowest quartile. Adjusted odds ratios for work intensification ranged from 1.74 (upper back) to 2.33 (neck). CONCLUSIONS: Most room cleaners experience severe back or neck pain. Severe pain showed strong associations with physical workload, work intensification, and ergonomic problems.     

The Effects of a Four-Week Muscle Strengthening Program on Maximum Acceptable Lifting Load

The purpose of this study is to investigate the effects of a traditional strengthening program on subjects' maximum acceptable lifting load. Nineteen (nine males, ten females) university students volunteered for the present study. They were randomly divided into a training group (five males, seven females) and a control group (four males, three females). The training group participated in 12 sessions of alternate day traditional dead weight strengthening programs for a period of 4 weeks. The measurements of the training effects included assessment of the maximum acceptable lifting load by psychophysical approach and isokinetic peak torque of the back extensors, knee extensors, shoulder abductors, and elbow flexors. Multivariate ANOVA was used to test for the training effect. Results revealed significant improvement in the maximum acceptable lifting load (p < 0.001) and back extensors peak torque (p = 0.039) after 4 weeks of training. It is concluded that a 4-week free weight muscle training program is effective in improving an individual's maximum acceptable lifting load. This type of physical training program may be useful to people engaged in manual material handling tasks.     

Short time effects of a low-frequency,high intensity magnetic field in the treatment of chronic neck and low back pain

IntroductionNeck and back pain afflicts millions of people. Magnetotherapy has shown to have anti-inflammatory effects that could act on pain generation, but the literature lacks provide a precise therapeutic protocol.MethodsA high-intensity electromagnetic field with a dedicated applicator was administered to 38 patients with low-back pain and 30 patients with neck pain. The device provides 60 mT and a frequency of 50 Hz for 30 minutes, the session was repeated 4 times.ResultsThe mean VAS of the low-back pain group decreased from 6.56 to 4.54, with a significant reduction of 30.8%. The mean VAS of the neck pain group decreased from 6.51 to 1.96, with a significant reduction of 69.9%.DiscussionThe treatment used showed good results in both groups of the patient, without side effects. The therapeutic protocol adopted is safe, provide rapid relief from the pain and is not time demanding. This treatment could represent an effective non-pharmacologic physical therapy option in the treatment of low-back pain and cervical pain.     

NIOSH提举指数在下背痛流行病学研究中的应用

[目的 ]探讨美国国家职业安全卫生研究所提出的手工作业提举指数 (LI)与下背痛患病率的关系。[方法 ]在 3个具有典型提举作业的工厂中采用流行病学横断面调查方法 ,利用NIOSH提出的提举指数进行接触负荷评价 ,按照Nordic肌肉骨骼症状分析调查表对 491名从事手工提举作业的工人和 3 4名无明显提举任务的行政人员进行问卷调查 ,并对静态肌力进行测试。根据提举指数分为 0 ,～ 1,～ 2 ,～ 3 ,>3共 5组。观察各组工人不同部位肌肉骨骼疾患的患病情况 ,并分析提举指数与下背痛患病的关系。 [结果 ]在肌肉骨骼症状中 ,下背痛的发生率最高。当LI增高时 ,下背痛的OR值也随之增加 ,但其峰值出现在～ 3组 (OR =1.3 5 ) ,而LI >3 ,其OR值并非最高 ,仅为 1.3 0。平均腰拉力最大的为～ 1组 ( 95 .5 9± 2 1.76)kg ,而对照组和LI >3组则分别为 ( 80 .3 6± 14 .49)kg、( 86.85± 2 0 .3 3 )kg。 [结论 ]提举指数对手工提举所引起的下背痛是一个有意义的危险度评价指标。过度手工提举活动可能降低腰拉力。     

Effect of bit wear on hammer drill handle vibration and productivity

The use of large electric hammer drills exposes construction workers to high levels of hand vibration that may lead to hand-arm vibration syndrome and other musculoskeletal disorders. The aim of this laboratory study was to investigate the effect of bit wear on drill handle vibration and drilling productivity (e.g., drilling time per hole).

A laboratory test bench system was used with an 8.3 kg electric hammer drill and 1.9 cm concrete bit (a typical drill and bit used in commercial construction). The system automatically advanced the active drill into aged concrete block under feed force control to a depth of 7.6 cm while handle vibration was measured according to ISO standards (ISO 5349 and 28927). Bits were worn to 4 levels by consecutive hole drilling to 4 cumulative drilling depths: 0, 1,900, 5,700, and 7,600 cm.

Z-axis handle vibration increased significantly (p<0.05) from 4.8 to 5.1 m/s² (ISO weighted) and from 42.7–47.6 m/s² (unweighted) when comparing a new bit to a bit worn to 1,900 cm of cumulative drilling depth. Handle vibration did not increase further with bits worn more than 1900 cm of cumulative drilling depth. Neither x- nor y-axis handle vibration was effected by bit wear. The time to drill a hole increased by 58% for the bit with 5,700 cm of cumulative drilling depth compared to a new bit.

Bit wear led to a small but significant increase in both ISO weighted and unweighted z-axis handle vibration. Perhaps more important, bit wear had a large effect on productivity. The effect on productivity will influence a worker's allowable daily drilling time if exposure to drill handle vibration is near the ACGIH Threshold Limit Value.^[1] ACGIH: 2017 TLVs and BEIs: Threshold Limit Values, ACGIH, Cincinnati, OH (2017). [Google Scholar] Construction contractors should implement a bit replacement program based on these findings.     

Barriers for Early Return-to-Work of Workers with Musculoskeletal Disorders According to Occupational Health Physicians and Human Resource Managers

Recent studies have indicated positive effects of modified work for workers with musculosceletal complaints. The question remains how effectively modified work can be implemented in companies. This study describes barriers for introducing modified work for workers on sickness absence due to musculoskeletal complaints. Modified work was defined as gradually increasing the physical demands at work until the worker is ready for full duty in his regular job. In order to describe barriers in implementation of modified work, a model based on health education was used, consisting of six successive stages. A questionnaire derived from this model was sent to human resource managers of different companies and their occupational health physicians. The internal consistency was estimated with the Cronbach's alpha. The results showed a large number of barriers for modified work. According to 52% of the company management and 54% of the occupational health physicians evident barriers were found due to lack of knowledge on modified work and negative attitudes of the employees. Both companies and physicians reported a barrier in the possibilities to change the work tasks (45-54%) or the organization of the work (45-38%). About 62% of the companies reported barriers due to a mismatch between the education of the sick worker and the specific requirements of modified work. Despite the assumed positive effects of modified work, the implementation process is hampered by a large number of barriers. A maximum effort from all parties involved is required for a successful rehabilitation process.     

Use of a Computerized Decision Support System for Primary and Secondary Prevention of Work-Related MSD Disability

The present study evaluates the effectiveness of a decision support system used to evaluate and control physical job stresses and prevent re-injury of workers who have experienced or are concerned about work-related musculoskeletal disorders. The software program is a database that stores detailed job information such as standardized work data, videos, and upper-extremity physical stress ratings for over 400 jobs in the plant. Additionally, the database users were able to record comments about the jobs and related control issues. The researchers investigated the utility and effectiveness of the software by analyzing its use over a 20-month period. Of the 197 comments entered by the users, 25% pertained to primary prevention, 75% pertained to secondary prevention, and 94 comments (47.7%) described ergonomic interventions. Use of the software tool improved primary and secondary prevention by improving the quality and efficiency of the ergonomic job analysis process.