Ergonomic exposures in apple harvesting: preliminary observations

Ergonomic Risk Factors for Musculoskeletal Disorders among Ethnic Lychee-Longan Harvesting Workers in Northern Thailand

Musculoskeletal disorders (MSDs) are one of the leading causes of occupational injuries and disabilities. The purpose of this study was to assess the prevalence of MSDs and occupational factors affecting MSDs among ethnic lychee-longan harvesting workers in northern Thailand. A cross-sectional study was conducted in the areas of three upper northern provinces of Thailand. The study areas are located in the highlands and rural plains, where many ethnic minority groups live, including Indigenous, Mien, Karen, and Lua. The majority of them work in a farm of perennial fruit trees, mainly lychee and longan. During the harvest season, 404 participants were recruited for the study using the convenience sampling technique. Data were collected using questionnaires that included general information, an ergonomic risk assessment, and a standardized Nordic questionnaire for assessing MSDs in 10 body parts. The average age of lychee-longan harvesting workers was 48.8 years. Almost all (99.5%) reported MSDs in one or more body regions in the previous seven days of work. The prevalence of MSDs was highest in the hands (82.9%), followed by the shoulders (82.2%) and the neck (79.7%). The total ergonomic risk scores, which included awkward posture, heavy carrying and lifting, repetitive activity, land slope, and equipment, were found to be significantly associated with MSDs in part of the neck (AOR = 1.17, 95%CI = 1.11-1.23), shoulder (AOR = 1.15, 95%CI = 1.10-1.21), elbow (AOR = 1.18, 95%CI = 1.12-1.24), hand (AOR = 1.12, 95%CI = 1.07-1.18), finger (AOR = 1.33, 95%CI = 1.24-1.44), upper back (AOR = 1.14, 95%CI = 1.09-1.20), lower back (AOR = 1.16, 95%CI = 1.11-1.22), hip (AOR = 1.11, 95%CI = 1.06-1.15), knee (AOR = 1.18, 95%CI = 1.12-1.24), and feet (AOR = 1.21, 95%CI = 1.15-1.28) when adjusting for ethnicity, sex, age, BMI, and work experience. Many parts of ethnic workers' bodies have been affected by occupational injuries, with a high risk of upper extremity injury. As a result, using an ergonomic approach to improving the working environment and appropriate posture movement is very beneficial in preventing MSDs among ethnic harvesting workers.

Musculoskeletal Disorders among Agricultural Workers of Various Cultivation Activities in Upper Northeastern Thailand

Musculoskeletal disorders (MSDs) are the most significant work-related health conditions that are experienced by agricultural workers. This cross-sectional study has investigated MSDs among agriculturalists in upper northeastern Thailand. We assessed the types of MSDs, their severity, and their frequency. There were 889 cultivating agriculturalists from four provinces who participated in this study. The majority of the participants reported experiencing mild levels of MSDs (60.48%). Predominantly, the farmers who were working on cassava, vegetable, and sugarcane plantations reported experiencing the most severe MSDs in the knees/calves (22.40%). The rice plantation workers reported the largest number of MSDs complaints. The workers on rubber plantations and in sugarcane fields were more likely to feel knee/calf pain (OR = 1.59, 95% CI = 1.05–2.39) and lower limb pain (OR = 1.97, 95% CI = 1.35–2.89) than those who were working on rice and tobacco plantations. The individuals who were working on cassava, fruit, vegetable, and corn plantations were also more likely to report knee/calf pain (OR = 1.48, 95% CI = 1.01–2.17) and lower limb pain (OR = 1.97, 95% CI = 1.37–2.84) than those who were working on rice and tobacco plantations. The MSDs that were found among those working on agricultural activities affected many parts of their bodies. The ergonomic risk needs to be assessed in order to inform plantation workers of the implications in order to improve their health and well-being and to reduce the risks of MSDs.

Biomechanical Exposure to Upper Extremity Musculoskeletal Disorder Risk Factors in Hospital Laboratories

Exposure to ergonomic risk factors has been reported for laboratory workers over decades. However, these exposures are not well characterized with respect to the type of laboratory or work organization. This study compared biomechanical exposure to upper extremity (UE) postures and hand activity levels (HALs) in general hospital laboratories by job, work, and laboratory type. The study used observational data gathered using a revised version of the Posture, Activity, Tools, and Handling (PATH) method, generating frequencies of categorized exposures. Eighteen workers were observed in 11 job titles (seven laboratories) in a single hospital by two investigators over a 7 month period. A taxonomy was constructed to categorize the extent to which the laboratory operations were automated. Overall, there were markedly high exposures to postural strain for the distal UE, especially wrist/forearm deviation (73% of observations), gross grasp (71%), and pinch grip (49%). For the HAL categories, 61% of the observations were in the moderate range (3.3–<6.7). Shoulders and elbows tended to remain in the neutral postural range. Posture frequencies were similar among the job categories studied and laboratory types. HAL was higher when the hand was in a pinch grip. Manual operations represented a higher proportion of work time than semi-automated or automated operations. Biomechanical exposure can be documented more extensively and diversely when using the revised PATH approach along with the taxonomy, with respect to exposure variables, such as the type of job, work, or organization in the industry including the hospital laboratories.

Prevalence of musculoskeletal disorders, ergonomics risk assessment and implementation of participatory ergonomics program for pistachio farm workers

Background and objectives:

Pistachio farmers are exposed to a variety of risk factors for musculoskeletal disorders (MSDs). However, no study has been conducted to investigate MSDs in pistachio workers. Therefore, in the present study, besides investigating the prevalence of MSDs and their ergonomic risk factors, the participatory ergonomics (PE) method is used to provide an intervention program to reduce MSDs in this population in harvesting and processing pistachio.

Methods:

The present study was conducted in two phases. In the first phase 138 workers participated. The prevalence of MSDs was assessed with Nordic Musculoskeletal Questionnaire and the ergonomic risk factors was identified with ManTRA method. In the second phase PE was used to perform ergonomic interventions for reducing MSDs and the effect of the intervention was investigated. Sixty-four workers participated in the second phase (32 in the case group and 32 in the control group).

Results:

The highest prevalence of MSDs was in shoulders (63.7%), followed by the lower back (63%) and wrists/hands (52.1%). The comparison showed that after implementing the PE intervention program, the prevalence of MSDs in the intervention group was not significantly different from that in the control group. However, in the reassessment by the ManTRA method for five tasks that were identified as high risk in the first phase, a decrease in ManTRA final score was observed for all the five tasks.

Conclusions:

MSDs were prevalent in all body regions of workers. After implementing PE interventions exposure to ergonomic risk factors decreased.

Comparisons of physical exposure between workers harvesting apples on mobile orchard platforms and ladders, part 1: Back and upper arm postures

This study compared farmworkers' exposure to non-neutral postures using a new mobile platform apple harvesting method and the traditional method using ladders. Twenty-four workers were recruited and assigned into three groups: ladder workers (n = 8) picking apples from full trees using a ladder, mobile platform workers (n = 8) picking apples from upper part of the trees while standing on a moving platform, and ground-based mobile platform workers (n = 8) picking apples from lower part of the trees which the mobile platform workers left out. Upper arm and back inclinations were continuously monitored during harvesting using tri-axial accelerometers over full work shifts (~8 h). Upper arm posture was characterized as the percentage of time that upper arm flexion and abduction exceeded 30°, 60°, and 90°. Back posture was characterized as the percentage of time that torso angles (sagittal flexion or lateral bending) exceeded 10°, 20°, and 30°. The 10th, 50th, and 90th postural percentiles were also calculated. The platform workers had lower exposures to upper arm flexion and abduction than the ground and ladder workers. There were no differences in torso angles between the ladder and mobile platform workers; however, the ground workers were exposed to more and greater percentages of time in torso flexions.

A feasibility study comparing objective and subjective field-based physical exposure measurements during apple harvesting with ladders and mobile platforms

Although mobile orchardplatforms have been developed to improve apple harvesting productivity in the US, the physical exposures of workers usingthe mobile platforms have not been well characterized, partlydue to the lack of assessment tools specific to the tree fruitorchard environment. The purpose of this study was to evaluate the feasibility and utility of different subjective and objective methods for characterizing apple harvesting workers' posture, armrepetition, heart rate, and perceived exertion during platform- and conventional ladder-based harvesting. During a regular full shiftwork (8 hours), the objective physical exposure measures (armelevation, torso inclination, and heart rate) of 6 platform, 6 ground, and 8 ladder workers were measured with tri-axial accelerometersand heart rate monitor; and subjective perceived exertion wascollected using standardized Borg RPE and CR-10 scales, translated into Spanish. The results showed that the arm elevation, torso forward bending, repetitiveness, heart rates, and perceived exertions were lower for the platform-based workers than forthe ladder-based workers. The subjective measures (Borg RPE and Borg CR-10) appeared to be similar and mirror the general trends of the objective heart rate and posture measures.These results indicate the potential benefit of these low-cost subjective measures when direct measurements are too costly,complicated, or not permitted. This study determined that field measurements of objective and subjective physical exposures were feasible for evaluating apple harvesting work. In summary, all themethods used appear to be feasible for field use in orchard-based environments..

Standing working posture and musculoskeletal pain among Citrus sinensis workers in a low-income country

Background. Work-related musculoskeletal pain (WRMP) among Citrus sinensis farm workers has barely been studied. Yet most work tasks in such farms are manually performed using awkward standing postures that can contribute to WRMP. Aim. This study assessed the standing working posture in relation to WRMP among C. sinensis workers. Methods. Ninety-two workers engaged in manual tasks participated in this cross-sectional study. Postures at the upper limbs were analysed using the rapid upper limb assessment (RULA) method. Data were analysed using SPSS version 20. Results. Analyses generally showed statistically significant associations (p < 0.05) between a body part RULA score and WRMP at the concerned body part. The upper arm score was >1 in 77.2% of the workers and caused upper arm pain in 66.3%; the association between the upper score and upper pain was statistically significant (χ ²= 20.57; p < 0.05). Similarly, significant associations were found between: (a) wrist score and wrist pain; (b) neck score and neck pain; (c) trunk score and back pain. Conclusions. C. sinensis workers use unsafe postures which contribute to WRMP at the upper arm, trunk, neck and wrists. Ergonomics measures are required to improve their working posture.

3D peak and cumulative low back and shoulder loads and postures during greenhouse pepper harvesting using a video-based approach

BACKGROUND

In agricultural field work many tasks have been cited as high priority risk factors for the development of work-related musculoskeletal disorders (WRMDs). Although video-based biomechanical approaches have been effective in documenting the physical demands and risks associated with various occupational and non-occupational tasks, to date, this method has yet to be used to document jobs such as crop harvesting in a greenhouse environment.

OBJECTIVE

To document and assess the postural characteristics and 3D peak and cumulative low back and shoulder loads associated with greenhouse pepper harvesting using a video-based posture sampling approach.

METHODS

Nine male (28.2 (4.1) years) pepper harvesters from a greenhouse in Southwestern Ontario, Canada were videotaped during a normal shift. 3DMatch was used to document working trunk and shoulder postures, from which 3D peak and cumulative forces and moments were quantified.

RESULTS

On average, workers spent the majority of their time in neutral trunk postures (lateral bend: 99.1%; axial twist: 59.9%; flexion: 89.8%). Consistent results were found for the left and right shoulder, with the arms held in a neutral flexion posture 50% of the time or more. Four participants experienced peak L4/L5 compression forces (between 4116.3 N and 5937.0 N) which exceeded the NIOSH Action Limit (3400 N) during the cart pushing/pulling task, but remained below the threshold during picking. Mean cumulative L4/L5 extension and shoulder flexion moments ranged in magnitude from 18.5 Nm to 28.2 Nm, and between 19.4 Nm and 23.2 Nm, respectively, across all tasks.

CONCLUSIONS

The postural characteristics and biomechanical loads associated with greenhouse pepper harvesting were quantified with a video-based biomechanical approach. Further investigations of the physical risk factors for low back and shoulder musculoskeletal disorders is warranted in pepper harvesting, given the postures and loads documented in this study.

Development and Evaluation of Ergonomic Interventions for Bucket Handling on Farms

OBJECTIVE

The aim of this study was to introduce and evaluate two interventions, Ergo Bucket Carrier (EBC) and Easy Lift (EL), for youths (and adults) to handle water/feed buckets on farms.

BACKGROUND

The physical activities of both adult and youth farm workers contribute to the development of low-back disorders (LBDs). Many of the activities youths perform on farms are associated with increased LBD risk, particularly, the handling of water and feed buckets.

METHOD

Seventeen adult and youth participants (10 males and seven females) participated in this study. To assess the risk of LBDs, the participants were instrumented with a three-dimensional spinal electrogonio-meter while lifting, carrying, and dumping water buckets using the traditional method and the two interventions.

RESULTS

For both the adult and youth groups, the results showed that the two interventions significantly decrease the magnitudes of LBD risk in many of the tasks evaluated. Overall, the use of the EBC resulted in a 41% reduction in the level of LBD risk for the carrying task and a reduction of 69% for the dumping task. Using the EL, on the other hand, is especially effective for lifting tasks (55% reduction in LBD risk). Results of the subjective response were consistent with the objective evaluations.

CONCLUSION

This study demonstrated the potential for ergonomic interventions in reducing LBD risk during the common farming task of bucket handling.

APPLICATION

Potential application of this study includes the introduction of the EBC and EL in family farms to reduce the LBD risk among youth and adult farmers.

A field study of exposure to whole-body vibration due to agricultural machines in a full-time rice farmer over one year

OBJECTIVES

The aims of this study were to clarify in detail the levels of whole-body vibration (WBV) exposure from a variety of agricultural machines in a rice farmer over one year, and to evaluate the daily level of exposure compared with European and Japanese threshold limits.

METHODS

The subject was a full-time, male rice farmer. We measured vibration accelerations on the seat pan and at the seat base of four tractors with various implements attached, one rice-planting machine, two combine harvesters, produced by the same manufacturer, and one truck used for transportation of agricultural machines. The position and velocity of the machines were recorded in parallel with WBV measurements. In addition, during the year starting in April 2010, the subject completed a questionnaire regarding his work (date, place, content, hours worked, machines used). We calculated the daily exposure to WBV, A(8), on all the days on which the subject used the agricultural machines.

RESULTS

The WBV magnitude in farm fields was relatively high during tasks with high velocity and heavy mechanical load on the machine, and had no dominant axis. The subject worked for 159 days using the agricultural machines during the year, and the proportion of days on which A(8) values exceeded the thresholds was 90% for the Japan occupational exposure limit and 24% for the EU exposure action value.

CONCLUSIONS

Our findings emphasize the need for rice farmers to have health management strategies suited to the farming seasons and measures to reduce WBV exposure during each farm task.

Evaluation of an ergonomics intervention among Nicaraguan coffee harvesting workers

This study evaluated an ergonomics intervention among Nicaraguan coffee harvesting workers, using electromyography and questionnaire survey techniques. Nicaraguan researchers were involved in the study so that they could gain hands-on experience with ergonomics research and applications, and eventually be the specialists conducting ergonomics interventions in Nicaraguan workplaces. Coffee harvesting activities were studied individually and physical hazards were identified accordingly. The results showed decreased muscle loading on the erector spinae muscle and improved comfort reporting in the back region compared to the commonly used baskets. This fulfils the design objective of a newly developed bag that was used in the intervention to reduce physical workload on the coffee harvesting workers. Workers' opinion survey results showed some issues related to the size of the new bag and the lumbar-shoulder belt mechanism. This information can be used in the modification of the bag in the next design. Key players in the process have been identified.

PRACTITIONER SUMMARY

Stimulating ergonomics activities in developing countries is suggested by many experts. This study provided an example from coffee workers in Nicaragua. Commonly used job evaluation procedures and physical load quantification methods were used. Ergonomics researchers and practitioners in developing countries may do similar projects on their own in the future.

Inter-rater reliability of PATH observations for assessment of ergonomic risk factors in hospital work

This study examined the inter-rater reliability of expert observations of ergonomic risk factors by four analysts. Ten jobs were observed at a hospital using a newly expanded version of the PATH method (Buchholz et al. 1996), to which selected upper extremity exposures had been added. Two of the four raters simultaneously observed each worker onsite for a total of 443 observation pairs containing 18 categorical exposure items each. For most exposure items, kappa coefficients were 0.4 or higher. For some items, agreement was higher both for the jobs with less rapid hand activity and for the analysts with a higher level of ergonomic job analysis experience. These upper extremity exposures could be characterised reliably with real-time observation, given adequate experience and training of the observers. The revised version of PATH is applicable to the analysis of jobs where upper extremity musculoskeletal strain is of concern.

Understanding the ergonomic risk for musculoskeletal disorders in the United States agricultural sector

INTRODUCTION

Farming is a very large industry in the United States. Understanding the risks for injuries and more specifically musculoskeletal disorders in this industry poses a challenge for health officials.

METHODS

A review was conducted of the existing peer-reviewed publications prior to December 2006 about injuries and musculoskeletal disorders for farmers and farm workers. The aim was to review existing knowledge concerning: (1) the prevalence, types, and causes of farm-related injuries, paying particular attention to musculoskeletal disorders and the special populations within the agricultural sector, and (2) interventions that have been developed to reduce risk factors associated with farm-related injuries.

RESULTS

Farmers and farm workers experience high rates of low back, shoulder, and upper extremity disorders. Musculoskeletal disorders may disproportionately affect farm youth and migrant workers due to the types of farm tasks performed. There is an urgent need for improved and validated interventions to reduce exposures and to improve the health of farmers and farm workers.

DISCUSSION

Future farm-related musculoskeletal disorder research should emphasize: (1) better identification of exposures for special populations, (2) development of interventions for diverse farm populations, and (3) identification of additional exposures for musculoskeletal disorders. Inadequate understanding of musculoskeletal disorders in farming impedes efforts to prevent this common and important type of occupational injuries on farms.

Low back pain and musculoskeletal symptoms among Kansas farmers

BACKGROUND

Farming continues to rank as one of the most dangerous occupations in the United States. The purpose of this study was to determine the prevalence of low back pain and other musculoskeletal disorders (MSDs) among the farmers and to examine the factors associated with occupational back pain. Farmers in a predominately corn and soybean growing region of Kansas served as the study sample.

METHODS

Questionnaires were mailed out to 499 active farmers of a Farmers' Cooperative in Southeast Kansas. The self-administered questionnaire was used to determine the prevalence of self-reported symptoms of back pain and other MSDs and to determine the strength of associations between back pain and work factors.

RESULTS

The participation rate was 57.2%. The low back was the anatomical area with the highest prevalence of self-reported work-related pain (37.5%), followed by the shoulders (25.9%), knees (23.6%), and neck (22.4%). Close to 60% of the farmers reported that they experienced farm work-related MSD symptoms in at least one of the nine body areas in the previous year. Nearly one quarter of the farmers reported seeing a physician for their low back symptoms, and one in five farmers had to modify their work habits due to low back symptoms during the previous year.

CONCLUSIONS

Low back pain and other musculoskeletal conditions are a significant problem for Kansas farmers. This group of Kansas farmers experienced low back pain at a much higher rate than the general working population and higher than other groups of farmers previously studied.

A descriptive study of workers' compensation claims in Washington State orchards

BACKGROUND

Previous studies have reported high rates of occupational injury and illness among workers in the tree fruit industry. However, many common and preventable risk factors and conditions in orchards have not been investigated.

AIMS

To identify and rank risk conditions leading to workers' compensation claims among orchard workers with respect to frequency, severity and cost.

METHODS

State Fund workers' compensation claims between 1996 and 2001 for orchard workers in the main tree fruit growing region of Washington were reviewed and categorized according to cause of injury. Descriptive analyses were performed to characterize claims by cause of injury.

RESULTS

Of the 13,068 claims in the dataset, 4,020 (31%) were determined to be ladder-related injuries. Ladder-related claims accounted for nearly half (48%) of all 'compensable' claims (e.g. claims involving time loss, disability or 'loss of earning power' in addition to medical expenses). Claims related to ladders were not only the most frequent but also the most expensive collectively in terms of medical aid, time loss and other costs. On a per-claim basis, ladder-related injuries were among the most severe and costly reported injuries. Other common causes of injury among claims were branches and vegetation, structure and material and ground-related injuries.

CONCLUSIONS

There is a strong and compelling need to develop interventions to reduce the number of ladder-related injuries in orchards.

Laboratory evaluation of belt usage with apple buckets

BACKGROUND

Migrant and seasonal orchard harvest workers experience musculoskeletal strain caused by carrying heavy loads and holding awkward postures. An ergonomic hip belt designed to redistribute weight from the upper back, neck, and shoulders to the hips was evaluated.

METHODS

A comparison of muscle exertion (using electromyography [EMG]) of four key back and shoulder muscles and shoulder surface pressure (using a surface pressure sensor [PS]) was made among 10 laboratory volunteers under intervention and control conditions, in two postures (standing erect [0 degrees ]) and flexed [45 degrees ]).

RESULTS

All but one measure showed a significant reduction in the flexed posture with the intervention. Two of eight measures showed a significant reduction in the erect posture. Correlations with shoulder discomfort were found for deep shoulder EMG (r=0.71, P=0.021) and shoulder surface pressure (r=0.58, P=0.082).

CONCLUSIONS

The hip belt intervention produces significant reductions in muscle activity while in a posture commonly assumed during orchard work.

Occupational risk among orchard workers: a descriptive study

Orchard workers are exposed to an array of occupational health and safety hazards that result in injury, illness, and, in some cases, death. The purpose of this qualitative study was to identify and explore factors that contribute to occupational risks related to orchard work. Twenty-five Hispanic orchard workers were interviewed. They reported that the most common type of accident was falls, usually from a ladder; and the most common injuries were strains and sprains. Three broad categories of factors that contributed to the occurrence of such injuries were Knowledge, Attitudes and Behaviors; Work-Related Factors; and Factors External to Work.