Risk of Traumatic Brain Injury in Deployment and Nondeployment Settings Among Members of the Millennium Cohort Study.

OBJECTIVE: To describe and quantify the prevalence and risk of deployment and nondeployment service-related traumatic brain injury (TBI) among participants of the Millennium Cohort Study. SETTING: Survey data. PARTICIPANTS: 28 759 Millennium Cohort Study participants who were active duty, Reserves, or National Guard at the time of the survey. DESIGN: Cross-sectional secondary data analysis. MAIN MEASURES: Estimates of prevalence and rates of TBI were calculated. Multivariable Poisson regression estimated rate ratios of TBI overall and stratified by deployment and nondeployment settings. RESULTS: The rate of TBI over the 362 535 person-years (PY) was 2.95 p/100 PY. the nondeployment rate was 2.15 p/100 PY, with a significantly higher rate (11.38 p/100 PY) in deployment settings. Bullets/blasts were the most common TBI mechanisms in deployed settings, while sports/physical training and military training were common in nondeployed settings. CONCLUSIONS: The risk of TBI as well as its mechanism varies by deployment and nondeployment, suggesting that targeted prevention strategies are needed to reduce the risk for TBI among military personnel based on their deployment status.

The association of employment status and unwanted job loss with maternal oral health experiences: findings from the pregnancy risk assessment monitoring system.

BACKGROUND: Oral health is an essential component of a healthy pregnancy. While most women work full-time while pregnant, research has overlooked the impact of occupational status and job loss on oral health experiences during pregnancy. To examine the impact of employment status and job loss on oral health experiences during pregnancy in the United States. DATA: Data are from eight sites (Georgia, Massachusetts, Minnesota, Missouri, North Carolina, New York State, New York City, and Wisconsin) of the Pregnancy Risk Assessment Monitoring System (PRAMS) for the years 2016-2020 (n = 31,362). Multiple logistic regression is used to assess the relationship between occupational status (including employment status and unwanted job loss) during pregnancy and oral health. FINDINGS: Women who experienced an unwanted job loss in the prenatal period were at elevated risk of not having dental insurance, not receiving a dental cleaning during pregnancy, having an oral health problem, and having unmet dental care needs. CONCLUSION: Experiencing unwanted job loss around the time of pregnancy is an important life event that corresponds to worse oral health experiences. There is a need for greater focus on adverse life events, such as job loss, especially during pregnancy, as a mechanism for oral health issues and challenges with proper access to dental health systems.

Maternal occupational exposure to chemicals and child cognitive function.

BACKGROUND: Limited data exist regarding child neurodevelopment in relation to maternal occupational exposure to endocrine-disrupting chemicals (EDCs). METHODS: We included 1058 mother-child pairs from the INfancia y Medio Ambiente (INMA) project (2003-2008). Using a job-exposure matrix, exposure probability scores for ten EDC groups were assigned to each mother based on her longest held job during pregnancy. At the child's 5-year visit, the McCarthy Scales of Children's Abilities was administered, yielding the general cognitive index and scales for specific cognitive domains. We analyzed region-specific associations between EDC exposures and each outcome separately using adjusted linear regression and combined region-specific effect estimates using random-effects meta-analyses. RESULTS: Approximately 24% of women were exposed to at least one EDC group, but exposure to most individual EDC groups was low (<5%). Maternal organic solvent exposure was associated with lower quantitative scores among children (-5.8 points, 95% confidence interval: -11.0, -0.5). Though statistically non-significant, exposures to polycyclic aromatic hydrocarbons, phthalates, alkylphenolic compounds, and miscellaneous chemicals were associated with poorer offspring performance for most or all cognitive domains. CONCLUSIONS: This study found limited evidence for a role of maternal occupational EDC exposures on child cognition. Further research is needed to better characterize exposures among pregnant workers. IMPACT: Using data from a prospective birth cohort, we help fill an important research gap regarding the potential consequences of work-related exposure to endocrine-disrupting chemicals (EDCs) among pregnant women on child neurodevelopment. We expand on existing literature-largely limited to pesticide and organic solvent exposures-by using a job-exposure matrix to estimate exposure to several EDC groups. We found limited evidence of an association between maternal occupational EDC exposure and children's overall cognition. We did observe specific associations between exposure to organic solvents and lower quantitative reasoning scores.

Impact of high, low, and non-optimum temperatures on chronic kidney disease in a changing climate, 1990-2019: A global analysis.

BACKGROUND: Although a few studies have reported the relationship between high and low temperatures and chronic kidney disease (CKD), the global burden of CKD attributable to extreme heat and cold in recent decades remains unknown. METHODS: Based on the Global Burden of Disease Study (GBD) 2019, we obtained data on age-standardized mortality rates (ASMR) and age-standardized rates of disability-adjusted life years (ASDR) per 100 000 population of the CKD attributable to non-optimum temperatures from 1990 to 2019. The annual mean temperature of each country was used to divide each country into five climate zones (tropical, subtropical, warm-temperate, cool-temperate, and boreal). The locally weighted regression model was used to estimate the burden for different climate zones and Socio-demographic index (SDI) regions. RESULTS: In 1990, the ASMR and ASDR due to high temperature estimated -0.01 (95% UI, -0.74 to 0.44) and -0.32 (-21.66 to 12.66) per 100 000 population, respectively. In 2019, the ASMR and ASDR reached 0.10 (-0.28 to 0.38) and 2.71 (-8.07 to 10.46), respectively. The high-temperature burden increased most rapidly in tropical and low SDI regions. There were 0.99 (0.59 to 1.39) ASMR attributable to low-temperature in 1990, which increased to 1.05 (0.61-1.49) in 2019. While the ASDR due to low temperature declined from 22.03 (12.66 to 30.64) in 1990 to 20.43 (11.30 to 29.26) in 2019. Overall, the burden of CKD attributable to non-optimal temperatures has increased from 1990 to 2019. CKD due to hypertension and diabetes mellitus were the primary causes of CKD death attributable to non-optimum temperatures in 2019 with males and older adults being more susceptible to these temperatures. CONCLUSIONS: The CKD burden due to high, low, and non-optimum temperatures varies considerably by regions and countries. The burden of CKD attributable to high temperature has been increasing since 1990.

Do health professionals' attitudes towards alcohol use matter for alcohol prevention efforts? Results from the WIRUS-OHS study.

BACKGROUND: Use of alcohol is a major public health issue, representing the 7th largest burden of disease in the world. Workplaces offer a unique arena for health initiatives addressing alcohol use, where occupational health services (OHS) personnel play an important role. However, we do not know if the extent of such initiatives may be influenced by personal drinking attitudes among OHS personnel. Thus, the aim of the study was to explore how drinking attitudes among OHS personnel were associated with their frequency of working with alcohol-related cases and with their views on alcohol prevention activities in the OHS. METHODS: The WIRUS project included a cross-sectional survey of attitudes and practices among OHS personnel (n = 325) employed by Norwegian OHS services (n = 69), who informed about sociodemographic and professional characteristics, drinking attitudes, frequency of cases with alcohol-related issues, and perceptions toward the role of the OHS in primary, secondary, and tertiary alcohol prevention activities. Measures of associations were examined with linear and logistic regression models. RESULTS: Drinking attitudes were unrelated to the frequency of working with alcohol-related cases. Physicians, psychologists, and nurses had higher frequency of working with alcohol-related cases, compared to those with other professional backgrounds (ß = 0.46, p = 0.01). Drinking attitudes were also unrelated to attitudes towards primary/secondary/tertiary alcohol prevention activities in the OHS, while female OHS personnel were more positive towards increased primary alcohol prevention activities in the OHS (OR: 1.82, p < 0.05). Only marginal portions (1%-3%) of the variance in attitudes towards alcohol prevention activities in the OHS were accounted for by the models. CONCLUSION: This study did not find evidence of associations between OHS personnel's drinking attitudes and their practices and attitudes towards alcohol prevention activities. The lack of association between OHS personnel's attitudes towards alcohol use and their attitudes and practices relating to alcohol prevention in the workplace might point towards professionalism, as personal attitudes appear not to interfere with their priorities and professional mission. Given the small amount of outcome variance explained by the tested models, other variables should be used in future studies.

A pilot study of total personal exposure to volatile organic compounds among Hispanic female domestic cleaners.

Cleaners have an elevated risk for the development or exacerbation of asthma and other respiratory conditions, possibly due to exposure to cleaning products containing volatile organic compounds (VOCs) leading to inflammation and oxidative stress. This pilot study aimed to quantify total personal exposure to VOCs and to assess biomarkers of inflammation and pulmonary oxidative stress in 15 predominantly Hispanic women working as domestic cleaners in San Antonio, Texas, between November 2019 and July 2020. In partnership with a community organization, Domésticas Unidas, recruited women were invited to attend a training session where they were provided 3M 3500 passive organic vapor monitors (badges) and began a 72-hr sampling period during which they were instructed to wear one badge during the entire period ("AT," for All the Time), a second badge only while they were inside their home ("INS," for INSide), and a third badge only when they were outside their home ("OUT," for OUTside). At the end of the sampling period, women returned the badges and provided blood and exhaled breath condensate (EBC) samples. From the badges, 30 individual VOCs were measured and summed to inform total VOC (TVOC) concentrations, as well as concentrations of the following VOC groups: aromatic hydrocarbons, alkanes, halogenated hydrocarbons, and terpenes. From the blood and EBC samples, concentrations of serum C-reactive protein (CRP) and EBC 8-isoprostane (8-ISP) and pH were quantified. Data analyses included descriptive statistics. The 72-hr average of personal exposure to TVOC was 34.4 ppb and ranged from 9.2 to 219.5 ppb. The most prevalent class of VOC exposures for most women (66.7%) was terpenes, specifically d-limonene. Overall, most women also experienced higher TVOC concentrations while outside their home (86.7%) as compared to inside their home. Serum CRP concentrations ranged from 0.3 to 20.3 mg/dL; 8-ISP concentrations ranged from 9.5 to 44.1 pg/mL; and EBC pH ranged from 7.1 to 8.6. Overall, this pilot study demonstrated personal VOC exposure among Hispanic domestic cleaners, particularly to d-limonene, which may result from the use of scented cleaning products.

Monitoring Self-Perceived Occupational Health Inequities in Central America, 2011 and 2018.

Objectives. To analyze changes in occupational health inequity between 2011 and 2018 among workers in Central America. Methods. Data were collected by face-to-face interviews at the workers' homes for the 2 Central America Working Conditions Surveys (n = 12 024 in 2011 and n = 9030 in 2018). We estimated health inequity gaps by means of absolute and relative population attributable risks and the weighted Keppel index. We stratified all analyses by gender. Results. Between 2011 and 2018, the proportion of workers reporting poor self-perceived health decreased both in women (from 32% to 29%) and men (from 33% to 30%). However, the health inequity gaps remained wide in the 4 stratifiers. Measured by the Keppel index, health inequity gaps between countries increased from 22% to 39% in women and from 20% to 29% in men. Conclusions. While health improved between 2011 and 2018, health inequity gaps remained wide. Wider health inequity gaps were observed between countries than by gender, age, occupation, or education. Public Health Implications. This first benchmark of occupational health inequities in Central America could be useful when developing and evaluating the impact of public policies on work.

Pilot study determining the feasibility of implementing the Disadvantaged Populations eGFR Epidemiology Study (DEGREE) protocol, point-of-care field measurements and a new module on risk factors for chronic kidney disease of unknown origin in Hispanic outdoor workers.

BACKGROUND: To field test the Disadvantaged Populations eGFR Epidemiology (DEGREE) protocol, outdoor point-of-care (POC) testing for serum creatinine, and a new risk factor module on chronic kidney disease of undetermined origin (CKDu) in U.S. outdoor Hispanic workers. METHODS: Fifty workers were interviewed in Houston (TX). DEGREE and CKDu questionnaires were completed indoors. Anthropometrics and paired blood samples for POC and laboratory assay were completed outdoors over two periods (November-December 2017, April-May 2018). RESULTS: Administration of DEGREE and CKDu questionnaires averaged 10 and 5 min, respectively, with all questions easily understood. We observed high correlations between POC and IDMS creatinine (r = 0.919) and BUN (r = 0.974). The POC device would disable testing when outdoor temperatures were above 85 °F or below 65 °F; this was adjustable. CONCLUSIONS: Implementation of DEGREE and the new CKDu module was straightforward and well understood. The POC device performed well in the field, with some adjustment in methods when temperature readings were out of range.

Reciprocal associations between depression, anxiety and work-related injury.

OBJECTIVE: To examine the reciprocal longitudinal associations between depression or anxiety with work-related injury (WRI) at a large employer in the southwestern United States. METHOD: Three administrative datasets (2011-2013) were merged: employee eligibility, medical and prescription claims, and workers' compensation claims. The sample contained 69 066 active employees. Depression and anxiety were defined as episodes of medical visits care (ie, claims) with corresponding ICD-9-CM codes. For an individual's consecutive claims, a new case of depression or anxiety was defined if more than 8 weeks have passed since the prior episode. The presence of a workers' compensation injury claim was used to identify WRI. Three-wave (health plan years 2011 or T1, 2012 or T2, and 2013 or T3) autoregressive cross-lagged models were used to estimate whether depression or anxiety predicted WRI, also if WRI predicted depression or anxiety in the following year(s). RESULTS: Depression predicted injury from T1 to T2 (ß=0.127, p<0.001) and from T2 to T3 (ß=0.092, p=0.001). Injury predicted depression from T1 to T3 (ß=0.418, p<0.001). Effects of anxiety on WRI were small and inconsistent, from T1 to T2 (ß=0.013, p=0.622) and from T2 to T3 (ß=-0.043, p=0.031). T1 injury had a protective effect on T3 anxiety (ß=-0.273, p<0.001). CONCLUSIONS: We found evidence of reciprocal effects for depression with WRI after adjustment for prior injuries and depression. The evidence for the relationship between anxiety and WRI is less clear. WRI prevention and management programmes should incorporate depression prevention and management.

Association of organic solvents and occupational noise on hearing loss and tinnitus among adults in the U.S., 1999-2004.

PURPOSE: Exposure to organic solvents and noise may be causal agents in the development of hearing loss and tinnitus. The objectives of the present study were to examine the association of organic solvents with hearing loss and tinnitus and to assess the interaction of organic solvent and occupational noise exposure on hearing loss and tinnitus. METHODS: A secondary data analysis of data from the National Health and Nutrition Examination Survey and Occupational Information Network (O*NET) among a study population ranging from 1085 to 2471 study participants from 1999 to 2004. Multiple multivariate logistic regression models were used to assess the associations of individual organic solvent exposures as measured by blood biomarkers (1,4-dichlorobenzene, benzene, ethylbenzene, styrene, toluene, o-xylene, and m-/p-xylene) with self-reported hearing loss, audiometrically assessed hearing loss, and self-reported tinnitus. Models were adjusted for age, gender, race/ethnicity, diabetes, non-occupational noise exposure, smoking, and income. Organic solvents found to be statistically significantly associated with the outcome after adjusting for covariates were tested for interaction with occupational noise exposure. RESULTS: Solvent exposure was not statistically significantly associated with self-reported tinnitus. Benzene (OR 1.43, 95% CI 1.15-1.78), ethylbenzene (OR 1.24, 95% CI 1.02-1.50), and toluene (OR 1.27, 95% CI 1.06-1.52) concentrations were statistically significantly associated with increased adjusted odds of high-frequency hearing loss. No statistically significant interaction was observed between these solvents and occupational noise on high-frequency hearing loss. CONCLUSIONS: We found no evidence of an association between organic solvents and tinnitus; however, there was evidence of an association between organic solvent exposure and prevalence of high-frequency hearing loss.

Reliability of observational- and machine-based teat hygiene scoring methodologies.

Removal of teat-end debris is one of the most critical steps in the premilking process. We aimed to estimate inter- and intra-rater reliability of an observation-based rating scale of dairy parlor worker teat-cleaning performance. A nonrandom sample of 8 experienced raters provided teat swab debris ratings scored on a 4-point ordinal visual scale for 175 teat swab images taken immediately after teat cleaning and before milking unit attachment. To overcome the uncertainty associated with visual inspection and observation-based rating scales, we assessed the reliability of an automated observer-independent method to assess teat-end debris using digital image processing and machine learning techniques to quantify the type and amount of debris material present on each teat swab image. Cohen's kappa coefficient (κ) was used to assess inter-rater score agreement on 175 teat swab images, and the intraclass correlation coefficient was used to assess both intra-rater score agreement and machine reliability. The reliability of debris scoring of teat swabs by raters was low (overall κ = 0.43), whereas the machine-based rating system demonstrated near-perfect reliability (Pearson r > 0.99). Our findings suggest that machine-based rating systems of worker performance are much more reliable than observational-based methods when evaluating premilking teat cleanliness. Teat swab image analysis technology can be further developed for training and quality control purposes to enable more efficient, reliable, and independent feedback on worker milking performance. As automated technologies are becoming more popular on dairy farms, machine-based teat cleanliness scoring could also be incorporated into automated milking systems.

Personality traits and career choices among physicians in Finland: employment sector, clinical patient contact, specialty and change of specialty.

BACKGROUND: Personality influences an individual's adaptation to a specific job or organization. Little is known about personality trait differences between medical career and specialty choices after graduating from medical school when actually practicing different medical specialties. Moreover, whether personality traits contribute to important career choices such as choosing to work in the private or public sector or with clinical patient contact, as well as change of specialty, have remained largely unexplored. In a nationally representative sample of Finnish physicians (N = 2837) we examined how personality traits are associated with medical career choices after graduating from medical school, in terms of employment sector, patient contact, medical specialty and change of specialty. METHODS: Personality was assessed using the shortened version of the Big Five Inventory (S-BFI). An analysis of covariance with posthoc tests for pairwise comparisons was conducted, adjusted for gender and age with confounders (employment sector, clinical patient contact and medical specialty). RESULTS: Higher openness was associated with working in the private sector, specializing in psychiatry, changing specialty and not practicing with patients. Lower openness was associated with a high amount of patient contact and specializing in general practice as well as ophthalmology and otorhinolaryngology. Higher conscientiousness was associated with a high amount of patient contact and specializing in surgery and other internal medicine specialties. Lower conscientiousness was associated with specializing in psychiatry and hospital service specialties. Higher agreeableness was associated with working in the private sector and specializing in general practice and occupational health. Lower agreeableness and neuroticism were associated with specializing in surgery. Higher extraversion was associated with specializing in pediatrics and change of specialty. Lower extraversion was associated with not practicing with patients. CONCLUSIONS: The results showed distinctive personality traits to be associated with physicians' career and specialty choices after medical school independent of known confounding factors. Openness was the most consistent personality trait associated with physicians' career choices in terms of employment sector, amount of clinical patient contact, specialty choice and change of specialty. Personality-conscious medical career counseling and career guidance during and after medical education might enhance the person-job fit among physicians.

The Identification of a Threshold of Long Work Hours for Predicting Elevated Risks of Adverse Health Outcomes.

Working long hours has been associated with adverse health outcomes. However, a definition of long work hours relative to adverse health risk has not been established. Repeated measures of work hours among approximately 2,000 participants from the Panel Study of Income Dynamics (1986-2011), conducted in the United States, were retrospectively analyzed to derive statistically optimized cutpoints of long work hours that best predicted three health outcomes. Work-hours cutpoints were assessed for model fit, calibration, and discrimination separately for the outcomes of poor self-reported general health, incident cardiovascular disease, and incident cancer. For each outcome, the work-hours threshold that best predicted increased risk was 52 hours per week or more for a minimum of 10 years. Workers exposed at this level had a higher risk of poor self-reported general health (relative risk (RR) = 1.28; 95% confidence interval (CI): 1.06, 1.53), cardiovascular disease (RR = 1.42; 95% CI: 1.24, 1.63), and cancer (RR = 1.62; 95% CI: 1.22, 2.17) compared with those working 35-51 hours per week for the same duration. This study provides the first health risk-based definition of long work hours. Further examination of the predictive power of this cutpoint on other health outcomes and in other study populations is needed.

Effect of informal employment on the relationship between psychosocial work risk factors and musculoskeletal pain in Central American workers.

INTRODUCTION: The constant increase on the psychosocial demands experienced at work seems to contribute to the increase in health problems such as musculoskeletal pain (MSP). This association may be especially important in low-income and middle-income countries, where there is a large proportion of informal workers among whom there is little research. We analysed the association between psychosocial work risk factors and MSP among formal and informal workers using the First Central American Survey of Working Conditions and Health. METHODS: This is a representative sample (n=12 024) of the economically active population of the six Spanish-speaking countries of Central America. Prevalence ratios (PR) and corresponding 95% CIs from Poisson regression models were used to estimate the association between psychosocial work risk factors and the MSP. RESULTS: Compared with formal workers, informal workers reported higher prevalence of MPS in the body regions analysed (ie, cervicodorsal, lumbosacral, upper extremities) and higher exposure to psychosocial work risk factors. However, on the whole, the associations between the exposure to psychosocial work risk factors and the prevalence of MSP were similar for both formal and informal workers. Only the association between exposure to high demands and MSP in the upper extremities was higher (p=0.012) among formal (PR=1.69, 95% CI 1.46 to 1.96) than among informal workers (PR=1.40; 95% CI 1.30 to 1.51). CONCLUSION: Exposure to adverse levels of psychosocial work risk factors is associated with higher prevalence of MPS among both formal and informal workers. However, the role of employment informality in this association is complex and requires further examination.

Low back pain among office workers in three Spanish-speaking countries: findings from the CUPID study.

OBJECTIVES: To assess the differences in the prevalence and incidence of low back pain (LBP) and associated disability among office workers in Costa Rica, Nicaragua and Spain. METHODS: Data were collected at baseline (n=947, 93% response) in November 2007 and at follow-up after 12 months (n=853, 90% response). Six outcome measures were examined: baseline prevalence of (1) LBP in the past 12 months, (2) LBP in the past month and (3) disabling LBP in the past month; and at follow-up: (4) incidence of new LBP in the past month, (5) new disabling LBP and (6) persistent LBP. Differences in prevalence by country were characterised by ORs with 95% CIs, before and after adjustment for covariates. RESULTS: Prevalence of LBP in the past month among office employees in Costa Rica (46.0%) and Nicaragua (44.2%) was higher than in Spain (33.6%). Incidence of new LBP was 37.0% in Nicaragua (OR=2.49; 95% CI 1.57 to 3.95), 14.9% in Costa Rica (OR=0.74; 95% CI 0.41 to 1.34) and 19.0% in Spain (reference). Incidence of new disabling LBP was higher in Nicaragua (17.2%; OR=2.49; 95% CI 1.43 to 4.34) and Costa Rica (13.6%; OR=1.89; 95% CI 1.03 to 3.48) than Spain (7.7%), while persistence of LBP was higher only in Nicaragua. CONCLUSIONS: Prevalence of LBP and disabling LBP was higher in Costa Rican and Nicaraguan office workers than in Spain, but the incidence was higher mainly in Nicaragua. Measured sociodemographic, job-related and health-related variables only partly explained the differences between countries, and further research is needed to explore reasons for the remaining differences.

Pulmonary function and airway inflammation among dairy parlor workers after exposure to inhalable aerosols.

BACKGROUND: Inhalation exposure to organic dust causes lung inflammation among agricultural workers. Due to changes in production and work organization, task-based inhalation exposure data, including novel lung inflammation biomarkers, will inform exposure recommendations for dairy farm workers. METHODS: Linear regression was used to estimate the associations of airborne exposure to dust concentration, endotoxin, and muramic acid with pulmonary outcomes (i.e., FEV1 , exhaled nitric oxide). Logistic regression was used to estimate associations with self-reported pulmonary symptoms. RESULTS: Mean exposure concentration to inhalable dust, endotoxin, and muramic acid were 0.55 mg/m3 , 118 EU/m3 , and 3.6 mg/m3 , respectively. We found cross-shift differences for exhaled nitric oxide (P = 0.005) and self-reported pulmonary symptoms (P = 0.008) but no association of exposure with respiratory outcomes. CONCLUSIONS: Inhalation exposures during parlor tasks, which were lower than previously reported and were not associated with cross-shift measures of pulmonary health among dairy workers. Modern milking parlor designs may be contributing to lower inhalation exposure. Am. J. Ind. Med. 60:255-263, 2017. © 2017 Wiley Periodicals, Inc.

Full-shift and task-specific upper extremity muscle activity among US large-herd dairy parlour workers.

US large-herd dairy parlour workers experience a high prevalence of musculoskeletal symptoms in the upper extremity. The purpose of this study was to estimate and compare full-shift and task-specific muscle activity of the upper extremity among parlour workers. Surface electromyography data were recorded continuously throughout a full work shift for each participant (n = 60). For a subset of participants (n = 33), muscular effort was estimated for milking task cycles. Lower muscle activity levels and higher per cent muscular rest was observed among rotary parlour participants as compared to herringbone and parallel parlour participants for anterior deltoid, forearm flexor and forearm extensor muscles. These findings suggest rotary parlours may offer workstation designs or work organisational dynamics which may be more beneficial to the health and performance of the worker, as compared to parallel or herringbone parlours. Practitioner Summary: Study findings suggest milking parlour configurations present different biomechanical demands on workers which may influence worker health and performance. Our findings will enable more informed decisions regarding both engineering (e.g. parlour configuration or milking equipment) and administrative (e.g. work organisation) control strategies for large-herd milking parlours.