A head-mounted display (HMD) with inappropriate mass and center of mass (COM) increases the physical workload of HMD users. The aim of this study was to investigate the effects of mass and COM of HMD ...on physical workload. Twelve subjects participated in this study. The mass and posteroanterior COM position were 0.8, 1.2, or 1.6 kg and −7.0, 0.0, or 7.0 cm, respectively. The subjects gazed at the target objects in four test postures: the neutral, look-up, body-bending, and look-down postures. The normalized joint torques for the neck and the lumbar region were calculated based on the measured segment angles. The results showed that the neck joint torque was significantly affected by mass and COM and it increased as the HMD mass increased for all test postures. The COM position that minimized the neck joint torque varied depending on the test postures, and the recommended ranges of COM were identified.
•A gazing task while wearing head mounted display (HMD) was conducted.•The HMD had different levels of the mass and center of mass (COM) positions.•The joint torques of neck and lumbar region were calculated during the task.•The neck joint torque was significantly affected by the mass and COM of HMD.•The proper COM position varied depending on the position of the target object.
Objective
Trade-offs between productivity, physical workload (PWL), and mental workload (MWL) were studied when integrating collaborative robots (cobots) into existing manual work by optimizing the ...allocation of tasks.
Background
As cobots become more widely introduced in the workplace and their capabilities greatly improved, there is a need to consider how they can best help their human partners.
Methods
A theoretical data-driven analysis was conducted using the O*NET Content Model to evaluate 16 selected jobs for associated work context, skills, and constraints. Associated work activities were ranked by potential for substitution by a cobot. PWL and MWL were estimated using variables from the O*Net database that represent variables for the Strain Index and NASA-TLX. An algorithm was developed to optimize work activity assignment to cobots and human workers according to their most suited abilities.
Results
Human workload for some jobs decreased while workload for some jobs increased after cobots were reassigned tasks, and residual human capacity was used to perform job activities designated the most important to increase productivity. The human workload for other jobs remained unchanged.
Conclusions
The changes in human workload from the introduction of cobots may not always be beneficial for the human worker unless trade-offs are considered.
Application: The framework of this study may be applied to existing jobs to identify the relationship between productivity and worker tolerances that integrate cobots into specific tasks.
This study aimed to investigate the effects of different tools and working heights on physical workloads in vertical cleaning tasks. Thirty healthy adults were recruited to use a rag and a ...long-handle tool (LHT) to simulate cleaning operations on the Wii Fit board surfaces of 3 different heights, respectively. Participants used a lower 50th percentile force but were required to spend a longer time to finish the task while using an LHT than using a rag. The tool preferences were the main factors considered for efficiency and personal subjective workload and physiological load. 76.6% of the participants preferred to use the LHT instead of the rag at a high task height, but 70% preferred to use the rag when working at a medium task height. For low workload cleaning tasks on vertical surfaces, employers should provide cleaners with different handle lengths tools to choose from to reduce the cleaner's workload.
•A lab study was conducted to evaluate the workload of vertical cleaning tasks.•The median force exertion and cleaning task time were inversely related.•There were distinct tool preferences for high- and mid-height vertical cleaning tasks.•No tool preference was found for low-height vertical cleaning tasks.
A decline in musculoskeletal health during pregnancy is an underappreciated adverse outcome of pregnancy that can have immediate and long-term health consequences. High physical job demands are known ...risk factors for nontraumatic musculoskeletal disorders in the general working population. Evidence from meta-analyses suggest that occupational lifting and prolonged standing during pregnancy may increase risk of adverse pregnancy outcomes. This systematic review examined associations between occupational lifting or postural load in pregnancy and associated musculoskeletal disorders and related sequalae.
Five electronic databases (Medline, Embase, CINAHL, NIOSHTIC-2, and Ergonomic Abstracts) were searched from 1990 to July 2022 for studies in any language. A Web of Science snowball search was performed in December 2022. Reference lists were manually reviewed.
Eligible studies reported associations between occupational lifting or postural load and musculoskeletal health or sequelae (eg, employment outcomes) among pregnant and postpartum workers.
Data were extracted using a customized form to document study and sample characteristics; and details of exposures, outcomes, covariates, and analyses. Investigators independently assessed study quality for 7 risk-of-bias domains and overall utility, with discrepant ratings resolved through discussion. A narrative synthesis was conducted due to heterogeneity.
Sixteen studies (11 cohort studies, 2 nested case-control studies, and 3 cross-sectional studies) from 8 countries were included (N=142,320 pregnant and N=1744 postpartum workers). Limited but consistent evidence with variable quality ratings, ranging from critical concern to high, suggests that pregnant workers exposed to heavy lifting (usually defined as ≥22 lbs or ≥10 kg) may be at increased risk of functionally limiting pelvic girdle pain and antenatal leave. Moreover, reports of dose-response relationships suggest graded risk levels according to lifting frequency, ranging from 21% to 45% for pelvic girdle pain and 58% to 202% for antenatal leave. Limited but consistent evidence also suggests that postural load increases the risk of employment cessation.
Limited but consistent evidence suggests that pregnant workers exposed to heavy lifting and postural load are at increased risk of pelvic girdle pain and employment cessation. Job accommodations to reduce exposure levels may promote safe sustainable employment for pregnant workers.
Display omitted
IntroductionMusculoskeletal pain (MSP) can affect the functional capacity of workers and engender reduced work ability (WA). The effect of MSP on WA may differ between workers with and without heavy ...physical workload/low decision authority. Although MSP is widespread in the workforce, only a few studies have explored this hypothesis.ObjectivesTo investigate the separate and combined effects of MSP and heavy physical workload/low decision authority on poor self-reported physical WA.MethodsThis study uses baseline data from the 2010 Stockholm Public Health Cohort (SPHC) questionnaire. The sample included 9419 workers with good baseline physical WA. Exposure to heavy physical workload and low decision authority were estimated using sex-specific job exposure matrices. The mean values for each exposure were dichotomised at the median (high/low) then combined with the presence of MSP. Follow-up data on poor self-reported physical WA were taken from the 2014 SPHC questionnaire. Logistic regression was performed adjusting for age, education, smoking, BMI, health conditions, psychological distress, and leisure-time physical activity. Additive interaction was estimated using the synergy index (SI).ResultsMSP, heavy physical workload and low decision authority were separately associated with poor WA. MSP was associated with higher odds of poor WA than heavy physical workload/low decision authority for women, the opposite was observed for men. Combined exposure to MSP and heavy physical workload/low decision authority was associated with the highest odds of poor WA (e.g, MSP and heavy physical workload men: AOR: 4.04, 95%CI: 2.00–8.15; women: AOR: 3.25 95%CI: 1.81–5.83). However, the SI was non-statistically significant for both sexes.ConclusionCombined exposure to MSP and heavy physical workload/low decision authority was associated with higher odds of poor WA than exposure to each factor separately. However, heavy physical workload/low decision authority did not statistically significantly aggravate the effect of MSP on the risk of poor WA.
IntroductionLow back pain (LBP) is one of the leading musculoskeletal disorders and it is a disabling occupational hazard. It is also a common cause of morbidity among the healthcare staff within ...were more vulnerable to LBP.ObjectivesThis study aimed to assess prevalence of LBP among healthcare staff and identify the socio-occupational hazards of this morbidity.MethodsThis is a cross-sectional study, carried out over 14 months, with 300 healthcare staff from two university hospitals in Tunisian center. It is based on an analysis of socio-occupational profile, the assesement of the Work Ability Index (WAI), the Nordic musculoskeletal questionnaire as well as assessment tests of physical condition and flexibility of the spine (hand-floor distance; sit-stand test; balance test)ResultsThe sex ratio of the sample was 1.06, the average age was 42.64 ±11.65. 20% of the healthcare staff in the sample had a BMI larger than 30 and 51.9% of them did not practice any regular sports activity. The perceived physical workload was considered « heavy » by 41.6% of the staff questioned. 75% of the healthcare staff in the sample had a good to excellent work ability according to the WAI. Over the 12 months preceding the survey, two third of the healthcare staff in the sample complained of LBP, with pain assessed as ‘severe’ or ‘extremely severe’ in 54.4% of cases. The LBP was statistically correlated with female gender (p=0.01) and with impaired work ability (p<10-3). The average finger-ground distance was 7.10 ± 7.5 cm and it was statistically correlated with LBP (p=0.05), with age (p<10-3), with seniority (p<10-3) and with a BMI ≥ 25 (p=10-3).ConclusionLBP persists as a real health problem among healthcare staff with heavy professional and social repercussions. Reducing their prevalence and impact is based on improving working conditions and multidisciplinary care.
IntroductionExposure to occupational noise has been implicated in the development of myocardial infarction (MI); however, the quality of previous evidence has been determined to be low, with few ...studies consisting mostly of men. Existing research also does consider other work exposures that may also affect MI risk. Thus, we aim to use a population-based cohort to investigate the impact of occupational noise on MI, while accounting for related work exposures.Materials and MethodsThis study is based on the SNOW cohort, which includes data on demographics, occupation, and diagnoses available for all individuals born between 1930 and 1990 and living in Sweden between 1968 and 2017. Working individuals between 1985 and 2013 were included. Exposure to noise was obtained by matching occupational codes to a job exposure matrix (JEM) developed using measurements and expert assessment, characterized in five levels (LAeq8h): <70, 70–74, 75–79, 80–84, 85+ dB(A). Additional occupational exposures considered were whole-body vibrations, chemicals, particles, physical workload, and psychosocial work environment. MI status was ascertained using diagnostic codes. Because occupational data can vary over time, we utilized a discrete-time proportional hazards model. Sensitivity analyses were done by restricting to low physical workload.ResultsPreliminary results show that exposure to over 85 dB(A) of occupational noise is associated with an increased risk for MI, after adjusting for age, gender, marital status, income, and country of birth, and exposure to whole-body vibrations, decision authority, carbon monoxide, diesel engine exhaust, oil mist, polycyclic aromatic hydrocarbons, pulp/paper, silica, and welding fumes. Restrictions to low physical workload resulted in similar effects.ConclusionsIn this working population, exposure to high levels of occupational noise was associated with an increased risk for MI, including among those with low physical workload. Analyses are ongoing to elucidate the role of other psychosocial working conditions.
IntroductionDisability retirement is one of the important paths of exit from paid employment and major reason for loss of working years. Knowledge on the contribution of work-related factors on ...occupational inequalities in cause-specific disability retirement is limited. We examined the impact of physical and psychosocial work-related factors on the occupational differences in disability retirement due to low back disorders, mental disorders, cardiovascular diseases and neurological diseases.Material and MethodsA total of 1 146 744 Finnish employees aged 30–60 years were followed from January 2005 to June 2016 for the first full disability retirement. In addition to all-cause disability retirement, we examined common non-communicable diseases such as low back disorders (sciatica and non-specific low back pain (LBP)), mental disorders, cardiovascular and neurological diseases separately. Information on pensions and occupation were obtained from national registers. Physical and psychosocial work-related factors were assessed by a gender-specific job exposure matrix. We examined the associations of occupation and exposures with disability retirement using competing risk regression model.ResultsControlling for age, physical workload and low job control were statistically significantly associated with disability retirement due to sciatica, non-specific LBP, cardiovascular and neurological diseases in both genders. For disability retirement due to mental disorders a weaker association of physical workload (women) and low job control (both genders) than for other outcomes was observed. Both men and women working in lower level non-manual and manual occupations had an elevated age-adjusted risk of all-cause and cause-specific disability retirement. The observed occupational differences in disability retirement due to sciatica and non-specific LBP were largely explained by physical workload and job control.ConclusionOur results suggest that physical workload and low job control appear to be the major reasons for excess disability retirement due to low back disorders in lower level non-manual and manual occupations.
This paper discusses about the manual material handling activities in the UD. Santosa. The activities give a particular injury because of the excessive load. Minimizing manual material handling can ...decrease and prevent a big number of injuries and fatigue. The increased rate of the injury that happened on the workers is also one of the indicator that there is excessive physical workload. This study aims to minimize the manual material handling and the physical workload by making multifunction trolley using anthropometrics. The method that used in this research is Cardiovascular Load, Anthropometrics. The result shows that the recommended weight load for each operator is 7.30411 kg, 5.93229 kg, 4.949725 kg, 2.88399 kg, and 2.594356 kg to avoid the risk of injury. For the physical workload for operators classified into 60% need to be improved and 40% no fatigue. The size for the multifunction trolley based on anthropometrics is 72.54 cm for the height of incline mode, 134.56 cm for the height of the trolley, 105.813 cm for the height of the of the hand holder, and 9.19177 cm for the width of the hand holder.
PDF
