Risk factors for work-related musculoskeletal disorders: A systematic review of recent longitudinal studies

Identification of physically demanding work tasks among cleaners: field study using electromyography

While chronic forearm pain is a common and debilitating condition among cleaners, the most physically demanding tasks remain unidentified. The present field study examines forearm muscle activity during 9 common cleaning tasks in a real working environment. Seven healthy cleaners participated in this study (age: 35.17 ± 9.62 yr; height: 168.17 ± 8.06 cm; weight: 77.14 ± 13.78 kg; experience: 5.60 ± 3.29 yr). Surface wireless electromyography (EMG) was recorded from 2 muscles on both sides of the upper limb, flexor carpi ulnaris (FCU), and extensor carpi radialis (ECR), and normalized to maximal voluntary isometric contractions (MVIC). Top-3 demanding high-force tasks (90th percentile EMG) were the rough floor, dirty rough floor, and office floor mopping for the FCU, and mopping high walls, ceiling mopping, and baize cleaning for the ECR. Top-3 static work tasks (10th percentile EMG) were mopping low walls, ceiling mopping, and dirty rough floors mopping for the FCU and mopping of high walls, low walls, and ceiling for the ECR. The study identified the forearm muscles' most physically demanding work tasks during cleaning tasks. The development of better working tools is recommended to avoid high-force overload as well as prolonged static overload of these muscles in cleaners.

Worker and work-related factors influence on musculoskeletal symptoms among veterinary surgeons

Worker and work-related musculoskeletal symptoms are prevalent among surgeons operating on human patients. Despite incidence rates for accidents among veterinarians and their staff being 2.9 times higher than that of general practitioners of human medicine, little is known about musculoskeletal symptoms among veterinary surgeons. In this study, 212 board-certified members of the American College of Veterinary Surgeons responded to a survey regarding various work-related activities and their experience with musculoskeletal symptoms in 10 different body regions. Across all body regions, reported pain increased from before to after a typical day of surgery (p <.01). Gender, weight, age, and years performing surgery were worker factors that were related to pain (p <.05), while number of procedures, practice focus, and proportion of minimally invasive surgery were work factors related to pain (p <.05). Our findings suggest that musculoskeletal symptoms are prevalent among veterinary surgeons and may help provide evidence for guidelines for minimising musculoskeletal injuries in veterinary surgery.Practitioner summary: Little is known about the risk factors for musculoskeletal symptoms (MSS) among veterinary surgeons. This cross-sectional survey of veterinary surgeons investigates worker and work factors related to MSS. We show that MSS are prevalent and identify key factors providing evidence that MSS are a concern in veterinary surgery.

Effects of a passive upper-body exoskeleton on whole-body kinematics, leg muscle activity, and discomfort during a carrying task

OBJECTIVE

To compare whole-body kinematics, leg muscle activity, and discomfort while performing a 10-min carrying task with and without a passive upper-body exoskeleton (CarrySuitⓇ), for both males and females.

BACKGROUND

Diverse commercial passive exoskeletons have appeared on the market claiming to assist lifting or carrying task. However, evidence of their impact on kinematics, muscle activity, and discomfort while performing these tasks are necessary to determine their benefits and/or limitations.

METHOD

Sixteen females and fourteen males carried a 15kg load with and without a passive exoskeleton during 10-min over a round trip route, in two non-consecutive days. Whole-body kinematics and leg muscle activity were evaluated for each condition. In addition, leg discomfort ratings were quantified before and immediately after the task.

RESULTS

The gastrocnemius and vastus lateralis muscle activity remained constant over the task with the exoskeleton. Without the exoskeleton a small decrease of gastrocnemius median activation was observed regardless of sex, and a small increase in static vastus lateralis activation was observed only for females. Several differences in sagittal, frontal, and transverse movements' ranges of motion were found between conditions and over the task. With the exoskeleton, ROM in the sagittal plane increased over time for the right ankle and pelvis for both sexes, and knees for males only. Thorax ROMs in the three planes were higher for females only when using the exoskeleton. Leg discomfort was lower with the exoskeleton than without.

CONCLUSION

The results revealed a positive impact on range of motion, leg muscle activity, and discomfort of the tested exoskeleton.

Work-related musculoskeletal disorders, fatigue and stress among gas station workers in China: a cross-sectional study

INTRODUCTION

Work-related musculoskeletal disorders (WMSDs) are disorders of the musculoskeletal system that have the highest prevalence among workers worldwide. Workers in gas stations usually work in poor ergonomic working conditions, including prolonged standing and repetitive posturing.

OBJECTIVE

The study aimed to investigate the prevalence of WMSDs and fatigue and to identify the predictors of WMSDs among gas station workers.

DESIGN

The present study was a cross-sectional study.

SETTING AND PARTICIPANTS

2962 gas station workers from an oil and gas company in China, with ages ranging from 17 to 75 years old, 55.47% female.

RESULTS

The prevalence of WMSDs within the 12 months prior to the study was 73.23%, with the highest prevalence in the neck, shoulders, ankles and feet. Furthermore, a correlation was observed between fatigue, stress and WMSDs. Fatigue and job role were the strongest predictors of WMSDs, with an OR range of 2.211-3.413.

CONCLUSIONS

This research identified the detrimental impact of WMSDs and fatigue on gas station workers, indicating the critical need for interventions to reduce WMSDs and relieve fatigue.

Work-Related Psychosocial Factors and Their Effects on Mental Workload Perception and Body Postures

The perception of work is closely linked to body reactions that facilitate task performance. Previous studies have shown that psychosocial work factors significantly impact employee health on both psychological and physical levels, though their cross-sectional designs limit causal interpretations. In this study, participants performed sitting and standing tasks under four different levels of mental workload. The NASA-Task Load Index (NASA-TLX) assessed mental workload perception across six dimensions, while Rapid Entire Body Assessment (REBA) and Rapid Upper Limb Assessment (RULA) scores evaluated body postures for standing and sitting tasks, respectively. This study examined the effects of alarms, distractions, and time constraints-common psychosocial factors in healthcare environments-on human behavior. We compared NASA-TLX scores with corresponding REBA/RULA scores to evaluate how perceived mental workload affects body postures. One-way ANOVA assessed the impact of experimental conditions on response variables, and Pearson correlation analyses explored the relationships between psychosocial factors and these variables. Results indicated that alarm conditions most negatively impacted mental workload perception and body postures. Temporal demand and effort scores were particularly affected by psychosocial factors in both tasks. Gender influenced physical demand and performance scores (higher in females) for the standing task but did not affect REBA and RULA scores. These findings suggest that organizational and psychosocial factors significantly influence healthcare workers' behavior, health, and patient safety. Further research is needed to evaluate the specific effects of psychosocial factors on both physical and mental workload to understand the relationship between overall task workload and occupational disorders.

Transport and mining machinery cabins' ergonomic evaluation as a path to its redesign

Transport and mining machinery cabins are still not well adapted to their users, while checklists for their evaluation are not common in the literature. This article proposes a new checklist for ergonomic evaluation and tests its universality empirically with a sample of 96 transport and mining machine operators. The objective of the article is two-fold. First, the article checks whether there are anthropometric dimension differences between different machines' operators. Second, statistical significance testing regarding items in the proposed checklist is performed to check its universality. Significant differences have not been found between anthropometric dimensions of transport and mining machine operators. Group comparisons prove that mining machines have better ergonomics characteristics of the chair, manual controls and vision field. The recommendation for crane designers is to examine mining machines solutions and analyze the possibility of adapting these solutions, due to anthropometric fit. Wide usage of the checklist is recommended.

Exploring the influence of individual factors on the perception of mental workload and body postures

Studies have revealed that physical and mental demands, psychosocial factors, and individual factors can contribute to the development of WMSDs. Yet, much is still unknown regarding the effects of individual characteristics on WMSDs susceptibility. Previous studies discovered people assumed more awkward body postures to perform an activity when the perception of mental workload is higher. This research study explored if individual characteristics such as age, sex, personality, and anxiety help explain changes or differences in the perception of mental workload and body postures assume when performing activities. The study provided evidence that these individual characteristics have a modifying role on perceived mental workload and body postures. The results suggest that perceived mental workload is influenced to a higher extent by individual characteristics such as anxiety, sex, and personality traits. Women have a higher (18.7%) mental workload perception than men. Likewise, NASA-TLX scores are 22% higher for feelers than thinkers. In general, higher perceptions of mental workload were observed in participants with higher anxiety levels. On the other hand, body postures seem to be influenced by different individual factors depending on the nature of the activity. RULA scores increased on average by 13.1% between baseline and time constraint conditions. Larger differences were observed in certain individuals (e.g. introverts (19.7%) and intuitors (13.8%)) across conditions.

In-Field Training of a Passive Back Exoskeleton Changes the Biomechanics of Logistic Workers

OCCUPATIONAL APPLICATIONSOccupational exoskeletons receive rising interest in industry as these devices diminish the biomechanical load during manual materials handling. Still, we have limited knowledge when it comes to in-field use. This gap often contributes to failure in the implementation of exoskeleton in industry. In this study, we investigated how a training protocol consisting of in-field use of a passive back exoskeleton affected the biomechanics of logistic workers. More specifically, we focused on how the variation of the muscular and kinematic patterns of the user was altered after exoskeleton training. We found that training had a positive effect on exoskeleton use, as a relative decrease of 6-9% in peak back muscle activity was observed post-training. Additionally, training decreased knee flexion by 6°-16°, indicating a more stoop lifting technique. The findings point at the potential benefits of applying a training approach when implementing a back-supporting exoskeleton in logistics.

Work-related musculoskeletal disorders among desludging operators in Uganda

BACKGROUND

Despite the limited evidence, desludging operators remain at a heightened risk of work-related musculoskeletal disorders (WMSDs). This study established the prevalence and predictors of WMSDs among desludging operators in Uganda.

METHODS

A digitalized structured questionnaire was used to collect cross-sectional data on musculoskeletal disorders and routine workplace activities from 303 desludging operators in 11 cities in Uganda. These cities were purposively selected based on the presence of a fecal sludge treatment plant or wastewater treatment plant. The Nordic Musculoskeletal Questionnaire (NMQ) was used to assess WMSDs. Simple random sampling with replacements was used to select respondents. Data were analyzed using STATA version 15.0. Modified Poisson Regression was used to measure the strength of association between the independent variables and WMSDs.

RESULTS

A total of 303 study participants were interviewed (97.7% response rate). The average age of the respondents was 34.0 years (SD ± 9.8). The prevalence of WMSDs among desludging operators was 29.7%. The body parts affected by MSDs were; the elbow for 4.6% (14/303), shoulder for 5.0% (15/303), and wrist/hand for 6.3% (19/303) of the respondents. At multivariable analysis, after controlling for age, desludging operators' ability to influence the availability of equipment needed to do their work (APR = 0.45, 95% CI: 0.20-0.99), and feeling that everything done was an effort (APR = 1.70, 95% CI: 1.01-2.87) were significantly associated with WMSDs.

CONCLUSION

The prevalence of WMSDs was high among desludging operators in Uganda. Desludging operators' ability to influence the availability of equipment needed to do their work and frequency of feeling that everything done was an effort were significantly associated with WMSDs. Interventions should focus on ensuring adequate provision of ergonomic equipment and promoting practices that reduce the physical strain associated with desludging tasks. Additionally, comprehensive training programs addressing proper lifting techniques and posture awareness could significantly mitigate the risk of WMSDs among desludging-operators.

Musculoskeletal disorders and visual problems among surgical versus medical physicians: A cross-sectional study

The healthcare industry is one of the main industries with a high prevalence of musculoskeletal disorders (MSDs). Surgical practice mostly involves repetitive tasks with fine motor control, precise motions, high levels of mental concentration, and close visual focus. This cross-sectional study aimed to define the prevalence and risk factors of MSDs and visual problems among physicians. One hundred surgical physicians and one hundred medical physicians were involved in the study. Both groups underwent assessment of socio-demographic and occupational history, alongside evaluation for musculoskeletal and visual problems. The study revealed a significantly higher prevalence of MSDs, particularly neck and back pain, as well as blurred near vision and eye dryness, among surgical physicians compared to medical physicians. Risk factors for these conditions included long working hours (≥30 h/week) in clinics or operating rooms, as well as using endoscopes and microscopes/loupes during surgery. In conclusion, MSDs and visual problems were prevalent among physicians, particularly surgical physicians. Integrating ergonomic principles across all domains of healthcare and promoting healthcare worker awareness through training and intervention programs are crucial steps in addressing these issues.

Impacts of ergonomic risk factors on the well-being and innovation capability of employees in the manufacturing industry

Objectives. Although various studies have examined the relationship between ergonomic factors and employee well-being, the impacts of ergonomic factors on workers' capability for innovation have not yet been studied in the manufacturing industry. This study advances understanding of the relationship between ergonomic risk factors and employees' capability to innovate and to feel good at work in the manufacturing sector. Methods. The analysis uses the structural equation modeling technique based on cross-sectional data collected from 200 experienced workers in manufacturing industries using self-administered close-ended questionnaires. Results. Findings from this research show that the main ergonomic factors influencing the well-being and innovation capability of employees in the manufacturing industry are neutral awkward posture, psychological risk factors and effective utilization of information and communications technology infrastructures. Thus, ergonomic factors are significantly correlated to the innovation capability of employees. Conclusion. As there have been no studies addressing the integration of ergonomic risk factors and the capability for innovation of employees in the manufacturing industry, this study provides a unique contribution to the body of knowledge. Further research is also required to develop an in-depth understanding of the relationship among components of each ergonomic risk factor, and the well-being and innovation capability of employees.

Workplace Psychosocial Factors, Work Organization, and Physical Exertion as Risk Factors for Low Back Pain Among US Workers: Data From the 2015 National Health Interview Survey

OBJECTIVE

To evaluate the association between workplace psychosocial, organization, and physical risk factors with low back pain (LBP) among US workers.

METHODS

2015 National Health Interview Survey data were analyzed to calculate the prevalence rates and prevalence ratios for LBP across levels of workplace psychosocial and organizational risk factors among 17,464 US adult workers who worked ≥20 hours per week. Results were also stratified by workplace physical exertion.

RESULTS

The adjusted prevalence rates of LBP were significantly elevated for workers reporting high job demand, low job control, work-family imbalance, bullying, job insecurity, working alternate shifts, and physical exertion. Job control and nonstandard shifts were significantly associated with LBP only among those who reported low/no physical exertion.

CONCLUSIONS

LBP prevalence was associated with select workplace psychosocial and organization risk factors. Stratification by physical exertion modified multiple associations.

Health risk assessment and prevalence of work-related musculoskeletal disorders among the aged brick molders, in India

The Brickfield Industry is the major and oldest informal industry in India, where millions of brickfield workers make their livelihood. Aged brickfield workers are also involved in different activities in the brickfield, especially in brick mold activities owing to poor socioeconomic conditions. A cross-sectional study was designed to determine the prevalence of work-related musculoskeletal disorders among the aged brick molders and compare them with aged control subjects. A Nordic Questionnaire was applied to assess the discomfort felt among both groups of workers and the Rapid Upper Limb Assessment (RULA) method was used to evaluate posture during their job. The RULA posture analysis showed that the posture adopted by aged brick molders required changes immediately. The result of the ART tool also stated that the brick molding activities' exposure level was high and required further investigation urgently. The study concluded that due to working in a forward bending posture for a prolonged period, aged brickmolders suffered from severe low back and knee pain along with upper-limb disorders due to repetitive activities.

A Rapid Review on the Effectiveness and Use of Wearable Biofeedback Motion Capture Systems in Ergonomics to Mitigate Adverse Postures and Movements of the Upper Body

Work-related diseases and disorders remain a significant global health concern, necessitating multifaceted measures for mitigation. One potential measure is work technique training utilizing augmented feedback through wearable motion capture systems. However, there exists a research gap regarding its current effectiveness in both real work environments and controlled settings, as well as its ability to reduce postural exposure and retention effects over short, medium, and long durations. A rapid review was conducted, utilizing two databases and three previous literature reviews to identify relevant studies published within the last twenty years, including recent literature up to the end of 2023. Sixteen studies met the inclusion criteria, of which 14 were of high or moderate quality. These studies were summarized descriptively, and the strength of evidence was assessed. Among the included studies, six were rated as high quality, while eight were considered moderate quality. Notably, the reporting of participation rates, blinding of assessors, and a-priori power calculations were infrequently performed. Four studies were conducted in real work environments, while ten were conducted in controlled settings. Vibration feedback was the most common feedback type utilized (n = 9), followed by auditory (n = 7) and visual feedback (n = 1). All studies employed corrective feedback initiated by the system. In controlled environments, evidence regarding the effectiveness of augmented feedback from wearable motion capture systems to reduce postural exposure ranged from strong evidence to no evidence, depending on the time elapsed after feedback administration. Conversely, for studies conducted in real work environments, the evidence ranged from very limited evidence to no evidence. Future reach needs are identified and discussed.

Human-in-the-Loop Optimization of Knee Exoskeleton Assistance for Minimizing User's Metabolic and Muscular Effort

Lower limb exoskeletons have the potential to mitigate work-related musculoskeletal disorders; however, they often lack user-oriented control strategies. Human-in-the-loop (HITL) controls adapt an exoskeleton's assistance in real time, to optimize the user-exoskeleton interaction. This study presents a HITL control for a knee exoskeleton using a CMA-ES algorithm to minimize the users' physical effort, a parameter innovatively evaluated using the interaction torque with the exoskeleton (a muscular effort indicator) and metabolic cost. This work innovates by estimating the user's metabolic cost within the HITL control through a machine-learning model. The regression model estimated the metabolic cost, in real time, with a root mean squared error of 0.66 W/kg and mean absolute percentage error of 26% (n = 5), making faster (10 s) and less noisy estimations than a respirometer (K5, Cosmed). The HITL reduced the user's metabolic cost by 7.3% and 5.9% compared to the zero-torque and no-device conditions, respectively, and reduced the interaction torque by 32.3% compared to a zero-torque control (n = 1). The developed HITL control surpassed a non-exoskeleton and zero-torque condition regarding the user's physical effort, even for a task such as slow walking. Furthermore, the user-specific control had a lower metabolic cost than the non-user-specific assistance. This proof-of-concept demonstrated the potential of HITL controls in assisted walking.

Short-acting opioid prescriptions and Workers' Compensation using the National Ambulatory Medical Care Survey

BACKGROUND

Short-acting opioids have been utilized for pain management with little known about their use in patients on Workers' Compensation (WC) insurance. Our goal was to investigate this association in the ambulatory care setting.

METHODS

Using the National Ambulatory Medical Care Survey, visits from patients aged 18-64 during the years 2010 until 2018 were evaluated (excluding 2017 due to data availability). Demographic and co-morbidity data from each visit was obtained along with the visit year. The first short-acting opioid medication prescribed in the database was considered. Survey-weighted frequencies were evaluated. Logistic regression estimated the crude and adjusted odds ratios (OR) with 95% confidence intervals for the use of short-acting opioid prescription.

RESULTS

There were 155,947 included visits with 62.5% for female patients. Most patients were White with 11.7% identifying as Black, and 6% identifying as another race. Over 13% of the sample was of Hispanic descent. WC was the identified insurance type in 1.6% of the sample population. Of these patients, 25.6% were prescribed a short-acting opioid, compared with 10.1% of those with another identified insurance. On multivariable regression, Black patients had increased odds of being prescribed a short-acting opioid compared to white patients (OR: 1.22, 95% CI: 1.11-1.34). Those on WC had 1.7-fold higher odds of being prescribed short-acting opioids (95% CI: 1.46-2.06).

CONCLUSION

Certain patient characteristics, including having WC insurance, increased the odds of a short-acting opioid prescription. Further work is needed to identify prescribing patterns in specific high-risk occupational groups, as well as to elicit potential associated health outcomes.

The impact of an active and passive industrial back exoskeleton on functional performance

Due to differences in actuation and design, active and passive industrial back exoskeletons could influence functional performance, i.e., work performance, perceived task difficulty, and discomfort, differently. Therefore, this study investigated and compared the impact of the active CrayX (7 kg) and passive Paexo Back (4.5 kg) on functional performance. Eighteen participants performed twelve work-related tasks with both types of exoskeletons and without (NoExo). The CrayX hindered work performance up to 22% in multiple tasks, compared to the Paexo Back and NoExo, while work performance between NoExo and the Paexo Back condition was more comparable, except for stair climbing (13% hindrance). Perceived task difficulty and discomfort seldomly varied between both exoskeletons. Although the CrayX shows promise to benefit workers, limitations in hindrance and comfort should first be addressed. The Paexo Back has demonstrated an advantage in certain static tasks. However, increasing its potential across a broader range of tasks seems warranted.Practitioner Summary: Differences between industrial back exoskeletons with regard to functional performance, i.e. work performance, discomfort and perceived task difficulty, were investigated by evaluating the active CrayX and passive Paexo Back back exoskeletons. The CrayX significantly hindered functional performance, while the Paexo Back seldomly affected functional performance.Abbreviations: WMSD: Work-related musculoskeletal disorder; NoExo: No Exoskeleton; GD: General discomfort; PTD: Perceived task difficulty; BMI: Body Mass Index.

Age and gender differences in the perception and use of soft vs. rigid exoskeletons for manual material handling

We investigated age and gender differences in the perception and use of soft (Apex) vs. rigid (Paexo Back) passive back-support exoskeletons (BSE) for repetitive lifting and lowering. A gender-balanced sample of 20 young (18-30 years) and 16 old (45-60 years) individuals were recruited. In the first session, participants' self-reported maximum acceptable load (MAL) was assessed using a psychophysical approach. Changes in muscle activity and kinematics due to BSE use in repetitive lifting/lowering tasks were also assessed. Overall, both BSEs increased MAL (by ∼7%), and reduced trunk extensor muscle activity across all groups (by ∼7-18%), compared to the control condition. Both BSEs promoted more squatting postures, increased quadriceps muscle activity (by ∼34%) and abdominal muscle activity during asymmetric tasks (by 5-20%). Some age and gender differences were significant, particularly for the trunk kinematics when using the Apex. Future work should include more diverse user groups in studying willingness to adopt BSEs and characterising their consequent effects on the body.

Prevalence and Biopsychosocial Factors Associated With a Current Episode of Low Back Pain Among Adults With a Previous History of Low Back Pain: A Cross-sectional Study of Market Traders in an African Population

Low back pain (LBP) is the leading cause of years lived with disability globally, with Nigeria having one of the greatest burdens. A current episode of LBP is important in Nigeria, but the associated factors are unknown. This cross-sectional study investigated the prevalence, biomechanical, and psychosocial factors associated with a current episode of LBP among 700 adult market traders with previous LBP in an urban Nigerian population. Descriptive, bivariate, and multivariate analyses were conducted. The prevalence of a current episode of LBP was 76.4%. Factors associated with an increased risk of a current episode of LBP in a decreasing order of importance were exposure to biomechanical factors (aggregate [total] score) (odds ratio [OR] = 1.535; 95% confidence interval [CI] = 1.398-1.685); anxiety (OR = 1.182; 95% CI = 1.089-1.282); fear-avoidance beliefs (physical activity) (OR = 1.139; 95% CI = 1.029-1.261); fear-avoidance beliefs (work) (OR = 1.105; 95% CI = 1.047-1.165); while factors associated with a reduced risk of a current episode of LBP were ability to take breaks in the job in addition to scheduled breaks (OR = .430; 95% CI = .240-.773) and ability to control the order and pace of tasks (OR = .477; 95% CI = .236-.965). Occupational biomechanical and psychosocial factors were associated with a current episode of LBP in logistic regression models explaining 52.7% and 73.1% of the variation in a current episode of LBP. Occupational biomechanical factors, particularly handling large and bulky objects at arm's length and kneeling and squatting, produced the greatest risk of a current episode of LBP. PERSPECTIVE: Occupational biomechanical factors, occupational psychosocial factors, and personal psychosocial factors such as anxiety and fear-avoidance beliefs are associated with a current episode of LBP in Nigeria. Pragmatic public health and occupational health initiatives that modify exposure to these factors may be required in Nigeria.

Hidden risk factors and the mediating role of sleep in work-related musculoskeletal discomforts

OBJECTIVE

Musculoskeletal discomforts (MSDs) are prevalent occupational health issues that are associated with a wide range of risk factors. This study aimed to investigate some of the occupational hidden risk factors and the mediating role of sleep in work-related musculoskeletal discomforts.

METHODS

In a cross-sectional study, the role of job stress and shift work as two hidden risk factors and sleep problems as the mediator in work-related musculoskeletal discomforts was investigated in 302 healthcare workers using the path analysis models. For this aim, healthcare workers' Occupational Stress and musculoskeletal discomforts were evaluated using the Health and Safety Executive questionnaire and Cornell questionnaire, respectively. Moreover, the Pittsburgh Sleep Quality Index (PSQI) and the Insomnia Severity Index (ISI) were used to examine the sleep characteristics of participants. Shift work and job stress as predictor variables and sleep characteristics as mediating variables were analyzed.

RESULTS

The results showed that the path coefficients of job stress on indexes of quality sleep and insomnia severity were significant. Also, the path coefficient of shift work on quality sleep index was significant. In return, the path coefficients of shift work on the insomnia severity index were not significant. Additionally, there was a mutually significant association between indexes of quality sleep and the severity of insomnia and musculoskeletal discomforts. The direct effect coefficient of job stress on MSDs was significant, whereas the direct effect coefficient of shift work on MSDs was insignificant. This means that shift work alone does not significantly impact these disorders.

CONCLUSION

It would seem that shift work and job stress as two occupational hidden risk factors can mediate sleep indexes and indirectly play a critical role in the incidence of musculoskeletal discomforts. Moreover, sleep disorders and musculoskeletal discomforts are mutually related and have a bidirectional relationship.

Determining whether biomechanical variables that describe common 'safe lifting' cues are associated with low back loads

Lift technique training programs have been implemented to help reduce injury risk, but the underlying content validity of cues used within these programs is not clear. The objective of this study was to determine whether biomechanical variables, that commonly used lifting cues aim to elicit, are associated with resultant low back extensor moment exposures. A sample of 72 participants were recruited to perform 10 repetitions of a floor-to-waist height barbell lift while whole-body kinematics and ground reaction forces were collected. Kinematic, kinetic, and energetic variables representative of characteristics commonly targeted by lifting cues were calculated as predictor variables, while peak and cumulative low back moments were calculated as dependent measures. Multiple regression revealed that 56.6-59.2% of variance in low back moments was explained by predictor variables. From these regression models, generating motion with the legs (both greater hip and knee work), minimizing the horizontal distance of the body to the load, maintaining a stable body position, and minimizing lift time were associated with lower magnitudes of low back moments. These data support that using cues targeting these identified variables may be more effective at reducing peak low back moment exposures via lift training.

Robot-assisted early mobilization for intensive care unit patients: Feasibility and first-time clinical use

BACKGROUND

Early mobilization is only carried out to a limited extent in the intensive care unit. To address this issue, the robotic assistance system VEMOTION® was developed to facilitate (early) mobilization measures more easily. This paper describes the first integration of robotic assistance systems in acute clinical intensive care units.

OBJECTIVE

Feasibility test of robotic assistance in early mobilization of intensive care patients in routine clinical practice.

SETTING

Two intensive care units guided by anesthesiology at a German university hospital.

PARTICIPANTS

Patients who underwent elective surgery with postoperative treatment in the intensive care unit and had an estimated ventilation time over 48 h.

METHODS

Participants underwent robot-assisted mobilization, scheduled for twenty-minute sessions twice a day, ten times or one week, conducted by nursing staff under actual operational conditions on the units. No randomization or blinding took place. We assessed data regarding feasible cutoff points (in brackets): the possibility of enrollment (x ≥ 50 %), duration (pre- and post-setup (x ≤ 25 min), therapy duration (x = 20 min), and intervention-related parameters (number of mobilizing professionals (x ≤ 2), intensity of training, events that led to adverse events, errors or discontinuation). Mobilizing professionals rated each mobilization regarding their physical stress (x ≤ 3) and feasibility (x ≥ 4) on a 7 Point Likert Scale. An estimated sample size of at least twenty patients was calculated. We analyzed the data descriptively.

RESULTS

Within 6 months, we screened thirty-two patients for enrollment. 23 patients were included in the study and 16 underwent mobilization using robotic assistance, 7 dropped out (enrollment eligibility = 69 %). On average, 1.9 nurses were involved per therapy unit. Participants received 5.6 robot-assisted mobilizations in mean. Pre- and post-setup had a mean duration of 18 min, therapy a mean of 21 min. The robot-assisted mobilization was started after a median of 18 h after admission to the intensive care unit. We documented two adverse events (pain), twelve errors in handling, and seven unexpected events that led to interruptions or discontinuation. No serious adverse events occurred. The mobilizing nurses rated their physical stress as low (mean 2.0 ± 1.3) and the intervention as feasible (mean 5.3 ± 1.6).

CONCLUSIONS

Robot-assisted mobilization was feasible, but specific safety measures should be implemented to prevent errors. Robotic-assisted mobilization requires process adjustments and consideration of unit staffing levels, as the intervention does not save staff resources or time.

REGISTRATION

clinicaltrials.org TRN: NCT05071248; Date: 2021/10/08; URL https://clinicaltrials.gov/ct2/show/NCT05071248.

TWEETABLE ABSTRACT

Robot-assisted early mobilization in intensive care patients is feasible and no adverse event occurred.

Changes in Baropodometric Evaluation and Discomfort during the Workday in Assembly-Line Workers

Prolonged standing at work is associated with health risks. The appearance of lower-limb and lower-back discomfort is one of the most prevalent factors in prolonged standing workers. The aim of this research was to evaluate the effect of an eight-hour workday on foot pressure and musculoskeletal discomfort in standing workers. Thirty-six assembly-line workers (six women) were recruited to participate in a cross-sectional study to assess foot pressure and surface, foot, knee, and lower-back discomfort before and after a real workday. Baropodometry outcomes (surface and pressure) were evaluated by the pressure platform SensorMedica and musculoskeletal discomfort was evaluated by Cornell's Musculoskeletal Discomfort Questionaire. Total foot surface (p = 0.01) and foot discomfort (p = 0.03) increased significantly at the end of the workday. Prolonged standing during 8 h workday increased the foot discomfort and total foot surface in assembly-line workers. No foot pressure variable (forefoot, rearfoot, or total) was significantly modified after the workday in assembly-line workers.

Influence of brick laying height on biomechanical load in masons: Cross-sectional field study with technical measurements

BACKGROUND

Work-related musculoskeletal disorders (WMSDs) located in the low back and neck/shoulder regions are major concerns for both workers, workplaces, and society. Masons are prone to WMSD, because their work is characterized by repetitive work and high physical workload. However, the knowledge on the physical workload during bricklaying is primarily based on subjective measurements.

OBJECTIVE

This cross-sectional field study with technical measurements aimed to quantify physical workload in terms of muscular activity and degree of forward bending during bricklaying at different working heights among masons, i.e., knee, hip, shoulder, and above shoulder height.

METHODS

Twelve male (36.1±16.1 years) experienced masons participated in a cross-sectional field study with technical measurements. Surface electromyography from erector spinae longissimus and upper trapezius muscles and an inertial measurement unit-sensor placed on the upper back were used to assess the physical workload (level of muscle activation and degree of forward bending) different bricklaying heights. Manual video analysis was used to determine duration of work tasks, frequency, type, and working height. The working heights were categorized as 'knee', 'hip', 'shoulder', and 'above shoulder'. The 95 percentiles of the normalized Root Mean Square (RMSn) values were extracted assess from erector spinae and trapezius recordings to assess strenuous level muscle of muscle activation.

RESULTS

The RMSn of dominant erector spinae muscle increased from hip- to shoulder height (from 26.6 to 29.6, P <  0.0001), but not from hip to above shoulder height and decreased from hip to knee height (from 26.6 to 18.9, P <  0.0001). For the dominant trapezius muscle, the RMSn increased from hip- to shoulder- and above shoulder height (from 13.9 to 19.7 and 24.0, respectively, P <  0.0001) but decreased from hip- to knee height (from 13.9 to 11.5, P <  0.0001). Compared to hip height (27.9°), an increased forward bending was detected during bricklaying at knee height (34.5°, P <  0.0001) and a decreased degree of forward bending at shoulder- and above shoulder height (17.6° and 12.5°, P <  0.0001, respectively).

CONCLUSION

Based on technical measurements, bricklaying at hip height showed the best compromise between muscular load and degree of forward bending. This study contributes to the development of the work environment for masons and can help guide preventive initiatives to reduce physical workload.

Work-related diseases and risk factors associated with work-related musculoskeletal disorders among unionized metal industry workers: a cross-sectional study

Objectives. This study aimed to determine the prevalence of work-related diseases (WRDs) and work-related musculoskeletal disorders (WR-MSDs), as well as investigate WR-MSD-associated risk factors, among metal industry workers in Turkey. Methods. The cross-sectional study was conducted with 1374 members of the Birleşik Metal İş Union from 121 companies. Data were collected using a self-administered 30-item questionnaire. Results. The survey response rate was 81.4% (1374/1686). Almost one out of every six workers (14.8%) stated that they had been diagnosed with a WRD, 3.6% reported that they had been diagnosed with an occupational disease and 38.6% of them indicated that they had suffered an occupational accident (OA) at least once. The prevalence of WR-MSDs was 10.7%, of work-related lung diseases was 1.8% and of occupational hearing loss was 0.6%. Quitting smoking, smoking, OA, heavy lifting, time pressure and working in the automotive industry were all associated with WR-MSDs. Conclusions. Interventions aimed at reducing musculoskeletal disorders (MSDs) should focus on smoking cessation, training workers in proper techniques and equipment for lifting and pushing/pulling heavy loads, preventing OAs and injuries, and reducing the time pressure in the workplace in the metal industry.

Mendelian randomization analysis reveals the impact of physical and occupational activities on the risk of gastroesophageal reflux disease and Barrett's esophagus

BACKGROUND

Recent studies have indicated that participating in physical activity may provide a safeguard against gastroesophageal reflux disease (GERD). Nevertheless, the precise links between physical and occupational activity and the occurrence of GERD and Barrett's esophagus (BE) are still uncertain.

METHODS

Conducting univariate and multivariate Mendelian randomization investigations to examine the causal relationship between exposures and outcomes. Genetic variation simulation was used in randomized experiments. Data on physical and occupational activity were obtained from the UK Biobank and GWAS catalog. In the meantime, data on GERD and BE were extracted from a high quality meta-analysis.

RESULTS

The results of univariate Mendelian randomization analysis using multiple methods suggest a causal relationship between strenuous sports or other forms of exercise (as a protective factor) and GERD/BE. At the same time, three types of occupational related physical activities, including heavy manual or physical work, shift work and walking or standing work, are risk factors for GERD/BE and have a causal relationship with them. These results were reconfirmed through multivariate Mendelian randomization analysis, which excluding the influence of other potential confounding factors.

CONCLUSIONS

The findings indicated that strenuous sports or other forms of exercise could lower the likelihood of GERD/BE, while excessive physical strain in the workplace, prolonged periods of standing or walking, and shift work could raise the risk of GERD/BE. Acknowledging this risk and implementing suitable measures can contribute to the prevention of GERD and BE, thus mitigating the associated health burden.

Sex differences in the impact of musculoskeletal disorders on health-related quality of life: a population-based study, Campinas, SP - ISACamp 2014/15

This article aims to estimate the prevalence of musculoskeletal disorders (MD) on the adult population of Campinas, São Paulo, Brazil, verifying associated demographic and socioeconomic factors, and to analyze their impact on Health-Related Quality of Life (HRQoL) according to sex. A population-based study was conducted with 2,166 individuals using data from the ISACamp 2014/15. The Medical Outcomes Study SF-36-Item Short Form Health Survey (SF-36) was used to measure HRQoL according to MD. Prevalence ratios (PR) were estimated by Poisson regression. Musculoskeletal disorders had a prevalence of 8.5% (6.7% tendonitis and 2.7% work-related musculoskeletal disorders - WMSD). Results showed a higher prevalence of musculoskeletal disorders in women, active or on leave due to illness, and in individuals with higher education levels. Moreover, reduced HRQoL scores were observed in 6 of the 8 domains, due to MD. The mental component and physical component showed greater impairment respectively among women and men after self-reported WMSD. These findings point to substantial damage from musculoskeletal disorders on the population's HRQoL. WMSD affect the HRQoL of men and women distinctly.

Shape Memory Alloy-Based Reactive Tubular (SMART) Brake for Compact and Energy-Efficient Wearable Robot Design

Soft wearable robots have been gaining increasing popularity for enhancing human physical abilities and assisting people who have physical limitations. These robots typically use tendon-driven mechanisms (TDMs) to enable remote actuation to provide better usability with compact design. TDMs comprise an actuator, an end-effector, and a transmission system by using cables or tendons to transfer forces from the actuator to the end-effector. Tendons are typically routed by frictionless guiding tubes to minimize force losses, variations in the force direction, and the volume. To make soft wearable robots even smaller, brakes need to be compacted because brakes are irreplaceable to ensure safety and energy efficiency. This study presents a shape memory alloy-based reactive tubular (SMART) brake for designing a compact and portable TDM-based device. The SMART brake actively adjusts the friction force between the brake and tendon, making it easy to achieve the desired friction state, ranging from low-friction states for free movement to high-friction states for effective braking. The brake is designed in a tubular shape, serving multifunctions as both a brake and a guiding tube. The brake's performance and theoretical model were validated through experiments and demonstrated by two wearable devices. The brake could hold a significant brake force of 19.37 N/11 mm while weighing only 0.3 g. These findings have major implications for the future development of TDM-based devices and soft wearable robots, paving the way for enhanced system portability, safety, and energy efficiency.

Challenges of Measuring Self-Reported Exposure to Occupational Biomechanical Risk Factors Amongst People with Low Literacy Engaged in Manual Labour: Findings from a Cross-Cultural Adaptation and Psychometric Investigation in an African Population with Chronic Low Back Pain

PURPOSE

Occupational biomechanical factors are implicated in the aetiology and progression of low back pain (LBP). This study cross-culturally adapted and psychometrically investigated the Occupational Risk Factor Questionnaire (ORFQ) in a low literate Nigerian Igbo population with chronic LBP.

METHODS

Forward and back translation of the original ORFQ by clinical and non-clinical translators was followed by an expert committee review. The adapted ORFQ was pre-tested amongst rural Nigerian adults with chronic LBP using cognitive think-aloud interviewing. Internal consistency (Cronbach's alpha) and test-retest reliability (unweighted and linear weighted k statistic for item-by-item agreement, and intra-class correlation coefficient-ICC) were investigated amongst 50 rural and urban Nigerian dwellers with chronic LBP. Spearman's correlation and regression analyses were conducted with the Igbo-ORFQ, and measures of disability [World Health Organisation Disability Assessment Schedule (WHODAS 2.0), Roland Morris Disability Questionnaire (RMDQ), Back performance scale (BPS)], pain intensity [Eleven-point box scale (BS-11)] and social support [Multidimensional Scale of Perceived Social Support (MSPSS)], to test construct validity with 200 rural Nigerian dwellers with chronic LBP.

RESULTS

Cross-cultural adaptation highlighted difficulty conceptualising and concretising exposure to biomechanical risk factors. Item-by-item agreement, internal consistency (α = 0.84) and intraclass correlation coefficient (ICC = 0.83) were good. Some unexpected direction of associations between the biomechanical components of the Igbo-ORFQ, and disability, pain intensity, and social support prohibits establishment of construct validity.

CONCLUSION

Prospective studies comparing the Igbo-ORFQ to other measures of exposure to occupational biomechanical risk factors are required to establish the construct validity of the Igbo-ORFQ.

The moderating effect of work-related musculoskeletal disorders in relation to occupational stress and health-related quality of life of construction workers: a cross-sectional research

BACKGROUND

This study aimed to investigate work-related musculoskeletal disorders (WMSDs), occupational stress, and health-related quality of life (HRQoL); identify the factors that affect HRQoL; and investigate the moderating effects of WMSDs on occupational stress and HRQoL.

METHODS

The participants were construction workers who had worked in the construction industry for over three months. A total of 178 construction workers voluntarily participated and anonymously completed the musculoskeletal symptoms questionnaire, the Korean Occupational Stress Scale, short-form 36. The moderation effect of WMSDs on occupational stress and HRQoL were analyzed by Haye's Process Macro Model.

RESULTS

The results of the study showed that 96 subjects (53.9%) had WMSDs, and the most common pain site was the lower back (33.3%). The group with WMSDs had higher occupational stress than did the group without WMSDs (p < 0.01). Compared with the group without WMSDs, the group with WMSDs displayed significant differences in HRQoL (p < 0.001). Furthermore, the factor affecting HRQoL was WMSDs (p < 0.001). In the impact of occupational stress on HRQoL, WMSDs had a significant moderating effect (p < 0.001).

CONCLUSION

The results of this study indicate that construction workers' WMSDs significantly impact occupational stress and HRQoL, and WMSDs have a significant moderating effect on the relationship between occupational stress and HRQoL. Therefore, to improve the HRQoL of workers in the construction industry, it is necessary to develop methods to reduce occupational stress and prevent and treat WMSDs.

The impact of remote work using mobile information and communication technologies on physical health: a systematic review

Remote e-working with information and communication technology (ICT) has long been on the rise, with its implementation accelerated by mandatory working from home regulations during the COVID-19 pandemic. This systematic literature review summarises the influencing factors of ICT-based remote e-working (device types, duration of use, user interfaces, etc.) on the physical health (musculoskeletal system and eyes) of knowledge workers. A search in four electronic databases and a manual search in four German journals resulted in 21 articles being included in this review. A bias analysis was conducted for all articles. Unfavourable postures, inappropriate working devices and certain environmental factors may cause a range of physical complaints, even after comparably short periods of time. Mostly, these complaints are greater compared to those experienced when working on a fully equipped stationary computer. Therefore, remote e-working requires careful planning, awareness, and the willingness to embrace working situations that counteract these problems.

Benchmarking commercially available soft and rigid passive back exoskeletons for an industrial workplace

Low-back pain is a common occupational hazard for industrial workers. Several studies show the advantages of using rigid and soft back-support passive exoskeletons and exosuits (exos) to reduce the low-back loading and risk of injury. However, benefits of using these exos have been shown to be task-specific. Therefore, in this study, we developed a benchmarking approach to assess exos for an industrial workplace at Hankamp Gears B.V. We assessed two rigid (Laevo Flex, Paexo back) and two soft (Auxivo Liftsuit 1.0, and Darwing Hakobelude) exos for tasks resembling the workplace. We measured the assistive moment provided by each exo and their respective influence on muscle activity as well as the user's perception of comfort and exertion. Ten participants performed four lifting tasks (Static hold, Asymmetric, Squat, and Stoop), while their electromyography and subjective measures were collected. The two rigid exos provided the largest assistance during the Dynamic tasks. Reductions in erector spinae activity were seen to be task-specific, with larger reductions for the two rigid exos. Overall, Laevo Flex offered a good balance between assistive moments, reductions in muscle activity, as well as user comfort and reductions in perceived exertion. Thus, we recommend benchmarking exos for intended use in the industrial workplace. This will hopefully result in a better adoption of the back-support exoskeletons in the workplace and help reduce low-back pain.

The ACGIH TLV for lifting: Estimated TLVs for torso asymmetry beyond 30 degrees

BACKGROUND

The American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLVs) for Lifting is a manual material handling (MMH) assessment method to identify weight limits that nearly all workers may be exposed to without developing work-related low back disorders (LBD). However, this assessment method only applies to lifting with the torso within 30° asymmetry of the sagittal plane.

OBJECTIVE

Estimate TLV weight limits while lifting with torso asymmetry greater than 30° beyond the sagittal plane.

METHODS

Lifting tasks were performed from various horizontal and vertical locations, at torso asymmetry angles of 0°, 15°, 30°, 45°, 60°, 75° and 90°, using ACGIH identified TLVs. Validated MMH assessment methods (NIOSH Lifting Equation, Ohio State University LBD Risk Model) were utilized to estimate TLVs at torso asymmetries greater than 30°.

RESULTS

The current ACGIH TLVs resulted in low- to moderate-risk risk levels for torso asymmetries from 0° to 30°, and the risk incrementally increased as torso asymmetry increased to 90°. With the intention to keep the risk levels to that found at 30° torso asymmetry, lower TLV weight limits in the vertical and horizontal zones investigated were estimated for torso asymmetries from 45° to 90°. The resulting adjusted TLVs were consistent with weight limits identified for similar lifting conditions from other assessment methods that account for torso asymmetry.

CONCLUSIONS

This research found current ACGIH-defined TLVs possess less than high-risk for LBD, and provided guidance to practitioners for reduced TLVs when torso asymmetry is greater than 30° from the sagittal plane.

The relationship between chronic diseases and the intensity and duration of low back pain

BACKGROUND

Low back pain (LBP) is a worldwide problem that affects numerous people and limits their mobility. Several factors, including chronic diseases, increase the risk of developing LBP. To date, the information available about the relationship between chronic diseases and the intensity and duration of LBP is quite limited.

AIM

The aim of the present study was to address the relationship between chronic diseases and both the intensity and duration of LBP.

DESIGN

This is an observational cross-sectional study.

SETTING

The study was conducted in the community of Saudi Arabia.

POPULATION

2181 adult participants (aged 18 years or more, mean age of 33 and standard deviation [SD] of ±11, 61% females) from Saudi Arabia with either recent or recurring LBP participated in the study.

METHODS

The participants of this study were surveyed, and their demographic information was obtained. They were asked whether they had LBP during the past year, and if they had, they were asked about their LBP in terms of the pain intensity on a scale that runs from 0 to 10, where 0 indicates no pain and 10 indicates extreme pain. Further, the participants were asked how long their pain lasted (in days). They were also inquired whether they had any of the following chronic diseases: diabetes mellitus, high blood pressure, hypotension, arthritis, cardiopulmonary diseases, kidney diseases, and hypothyroidism. Logistic regression was used to analyze the relationships between both of LBP's intensity and duration, and the presence of chronic diseases, while adjusting for the potential effect of age and gender.

RESULTS

A total of 2181 adults with either new onset of or recurrent LBP during the past 12 months participated in the present study. Of these, 356 (16%), who had LBP, suffered from one or more of the said chronic diseases. It was found that having one or more chronic diseases had statistically significant relationship with increased LBP's intensity (P=0.002), as well as prolonged duration (P=0.001). In particular, hypertension, arthritis, and hypothyroidism have statistically significant relationship with increased the intensity of the pain (P<0.05). Only, hypertension and arthritis have statistically significant relationship with increased the duration of pain (P≤0.001).

CONCLUSIONS

The presence of chronic diseases was associated with a more intense and longer duration of LBP.

CLINICAL REHABILITATION IMPACT

In view of the results of this study, we expect that those who have chronic diseases will have a longer duration of LBP and more intense pain.

The prevalence of work-related musculoskeletal disorder among health care workers in Damascus, Syria. A cross-sectional study

Background and Aims

Healthcare workers in particular frequently report Work-related musculoskeletal diseases (WRMSDs). The purpose of this study is to evaluate the prevalence and features of WRMSDs in residents from different specialties and trainee nurses from educational hospitals in Damascus, Syria.

Methods

A cross-sectional survey was undertaken aiming at the medical residents and the trainee nurses working in the public health sector in 11 hospitals. The sample size was found to be 2016. In this study, a modified version of the Standardized Nordic Questionnaire was employed.

Results

After the inclusion and exclusion criteria was the number of the participants 1855. In general, musculoskeletal pain was in the past week (69%) and the past 12 months (85%). Musculoskeletal pain in medical care practitioners was found to be linked to higher mean age (p = 0.0053) and body mass index (BMI) (p = 0.0437) in the last year. Females had a higher prevalence of WRMSDs than males (p = 0.0036), and those who were married also had a higher prevalence (p = 0.0218). Working longer hours per week and per month were associated with musculoskeletal pain in the previous 7 days (p = 0.0043 and p = 0.0003, respectively).

Conclusion

WRMSD prevalence was 85% among our study participants in the previous year. The most common complaint was lower back pain. Aging, female gender, and increasing BMI have been associated with higher reporting of WRMSDs. Our results suggested that doctors were twice as susceptible to developing WRMSDs as nurses. These results highlight the increasing urgency for ergonomics training programs and effective interventions to reduce WRMSDs and enhance working conditions for healthcare professionals in Syria.

Risks, solutions and implementation of a participatory ergonomic intervention in 16 day nurseries: A process evaluation of the TOY wait-list cluster-randomized controlled trial

More evidence-based initiatives to reduce physical work demands during childcare work to prevent ill health and promote the ability to care for the children among childcare workers are needed. In a process evaluation performed alongside a two-arm, cluster-randomized study with a waiting-list control among 16 day nurseries lasting 20-weeks that significantly reduced musculoskeletal pain-related sickness absence we investigated 1) risk factors and solutions perceived by the childcare workers, and 2) implementation of the intervention. Most of the perceived risk factors were categorized as physical (70 %) with most of the suggested solutions also being categorized as physical (61 %). The remaining risk factors were categorized as organizational risk factors (16 %) and psychosocial risk factors (13 %). The remaining solutions were distributed almost equally between the organizational (20 %) and psychosocial categories (19 %). About half (51 %) of the action plans showed high implementation success. Of 16 workshops, 100 % were delivered with a fidelity of 83 %. Average participation, exposure, responsiveness and implementation were 68 %, 56 %, 83 % and 47 %. The implementation score differed for timing of intervention but not for nursery characteristics. This study showed that complex and diverse participatory ergonomic interventions should focus on physical, organizational and psychosocial factors to have a positive effect.

Facilitators and Barriers to Implementing Interventions to Prevent Musculoskeletal Disorders in Blue-Collar Workers: A Scoping Review

PURPOSE

Blue-collar workers generally have less healthy lifestyles, poorer health, and a lower life expectancy than white-collar workers. At least in part this may be attributed to their work and working conditions. Employers increasingly provide interventions to improve health and wellbeing and prevent musculoskeletal disorders. However, they often do not reach blue-collar workers. The aim of this scoping review was to identify the facilitators for and barriers to implementing such interventions among blue-collar workers.

METHODS

A scoping review in which the study population of the selected studies consists of blue-collar workers (≥ 18 years old) in paid employment. Furthermore, included studies should report facilitators and barriers to implementing interventions to prevent musculoskeletal disorders. The literature search was conducted in six databases. The resulting studies were extracted with the help of the updated Consolidated Framework for Implementation Research.

RESULTS

15 articles were included; these were reviews, intervention studies, qualitative studies and process evaluations. A main facilitator was a participatory approach, which involves the blue-collar worker in the entire process of defining, developing, and implementing a multidimensional preventive intervention. The main barriers on the worker level were unfavorable worker characteristics and unsupportive behavior/attitudes. The main barriers on the organization level were a culture with a high production standard, a hierarchical culture, inflexible work, and an unsupportive attitude from the employer.

CONCLUSION

This review showed the multifaceted nature of implementation. A tailored implementation plan that involves the stakeholders (including workers) is important.

Occupational Risk Factors for Musculoskeletal Disorders among Workers in Dairy Diversification

BACKGROUND

In a changing European agricultural context, diversification of dairy farms is gaining attention. This study seeks to (1) assess musculoskeletal pain prevalence associated with tasks such as butter, yogurt, and cheese production; and (2) analyze associated risks.

METHODS

Observing 31, mostly female, workers, we utilized the ERGOROM questionnaire, a methodology adapted from the Institut National de Recherche et de Sécurité, and Key Indicator Method forms.

RESULTS

Findings revealed that tasks like load carrying (42% of workers), manual work (17%), and awkward postures (14%) resulted in musculoskeletal pain, predominantly in the lower back (65%), neck (39%), and dominant upper limb areas (shoulder: 61%, elbow: 26%, and wrist: 65%). While psychosocial risks remained low, concerns arose from workload, hygiene standards, and resource unpredictability.

CONCLUSIONS

As dairy farming evolves from artisanal to semi-industrial, our study emphasizes the importance of ergonomic adaptations to protect farmers' health and prevent musculoskeletal disorders during diversification.

Risk and related factors of elbow musculoskeletal diseases: a nationwide cross-sectional survey in China

OBJECTIVES

Although studies have shown that work-related musculoskeletal disorders (WMSDs) are common and continue to be a major source of disability and work time loss, there are few reports about elbow WMSDs. The aim of this study was to explore the prevalence and associated factors of elbow WMSDs.

METHODS

The valid questionnaires of 57501 workers from 15 different industries nationwide were collected and the c2 test and logistic regression analysis were applied to reveal the prevalence and risk factors of elbow WMSDs.

RESULTS

The findings indicated that the overall prevalence of elbow WMSDs among workers was 7.3%. However, the prevalence of elbow WMSDs in toy manufacturing was 21.3%, which was significantly higher than that in other industries (P < .05). Logistic regression analysis showed that age 40 and above, married, very poor health, left-handedness, lifting weights (more than 20 kg each time), work requiring upper limb or hand force, work in an uncomfortable position, repetitive operations within 1 minute, using vibrating tools, work involving cold, cool draughts, or temperature changes, work being completed in the same workshop, work being done outdoors, frequent dealings with customers, 2 shifts, often working overtime, staff shortage, and often working for colleagues were risk factors for elbow WMSDs. A higer education level, monthly income, and enough rest time were protective factors for elbow WMSDs.

CONCLUSIONS

Toy manufacturing is a high-risk industry for elbow WMSDs. Promotion of education about ergonomics should be strengthened, and workers' ergonomics awareness should be improved to reduce the impact of WMSDs.

Few sex-specific effects of fatigue on muscle synergies in a repetitive pointing task

Previous studies have identified some sex differences in how individual muscles change their activation during repetitive multi-joint arm motion-induced fatigue. However, little is known about how indicators of multi-muscle coordination change with fatigue in males and females. Fifty-six (29 females) asymptomatic young adults performed a repetitive, forward-backward pointing task until scoring 8/10 on a Borg CR10 scale while surface electromyographic activity of upper trapezius, anterior deltoid, biceps brachii, and triceps brachii was recorded. Activation coefficient, synergy structure, and relative weight of each muscle within synergies were calculated using the non-negative matrix factorization method. Two muscle synergies were extracted from the fatiguing task. The synergy structures were mostly preserved after fatigue, while the activation coefficients were altered. A significant Sex × Fatigue interaction effect showed more use of the anterior deltoid in males especially before fatigue in synergy 1 during shoulder stabilization (p = 0.04). As for synergy 2, it was characterized by variations in the relative weight of biceps, which was higher by 16 % in females compared to males (p = 0.04), and increased with fatigue (p = 0.03) during the elbow flexion acceleration phase and the deceleration phase of the backward pointing movement. Findings suggest that both sexes adapted to fatigue similarly, using fixed synergy structures, with alterations in synergy activation patterns and relative weights of individual muscles. Results support previous findings of an important role for the biceps and anterior deltoid in explaining sex differences in patterns of repetitive motion-induced upper limb fatigue.

Assessment and evaluation of work-related musculoskeletal disorders among nuclear medicine professionals in India: A cross-sectional study

BACKGROUND

Musculoskeletal disorders (MSDs) are a severe occupational health issue among medical radiation practitioners. It is mostly linked to personal protective wear, working posture, tools employed and ergonomics.

OBJECTIVE

To assess and evaluate the musculoskeletal disorders among nuclear medicine professionals (NMP) in India.

METHODS

An online survey was distributed to 455 NMP throughout India between November 2021 and March 2022 covering the demographic characteristics and questions for evaluation of musculoskeletal symptoms using the Standardized Nordic Musculoskeletal Questionnaire (NMQ). Participants with any pre-existing musculoskeletal disorder or trauma were excluded. Descriptive statistics summarized the data from the demographics, discomfort, aches and work-related musculoskeletal injuries. Chi-square test was used to examine the association between the obtained values.

RESULTS

91 out of 124 respondents were included based on the inclusion and exclusion criteria. Results shows that there is a significant association between the height of the individual and neck pain, body mass index and elbows pain, age and low back pain, experience in the current work and upper back pain, the weight of the individual and knee pain, use of mobile lead screens and shoulder pain, use of gonad shield, trouble in the ankles and use of lead screens, and QC phantoms for gamma camera / PET and wrists/hands pain.

CONCLUSION

Work-related musculoskeletal disorders among NMP are resulting from factors of individual demographic variables (such as age, height, weight, body mass index), years of experience at the current workplace and of using instruments in their work area.

Work-related injury or work-related pain? A qualitative investigation of work-related pain and injury management among rehabilitation professionals1

BACKGROUND

Patient mobility tasks place rehabilitation professionals (Physical and Occupational Therapists) working in hospitals at high risk for work-related musculoskeletal disorders (WMSDs). However, when investigating engagement with a Safe Patient Handling and Mobility program (SPHM), administrative records at a level one trauma hospital showed that rehabilitation professionals reported zero work-related injuries over an eight-year period.

OBJECTIVE

As part of a qualitative study conducted to discover their unique work experiences, we explored some of the reasons that rehabilitation professionals might not report work-related injuries to their employers.

METHODS

Using a collective case study design, six focus groups were conducted with 25 members of the rehabilitation team within a level-one trauma hospital. Focus groups were recorded; transcripts were analyzed for emergent themes using first and second cycle coding procedures.

RESULTS

Participants in this study denied experiencing work-related injuries but frequently described working in pain, often attributed to patient mobility tasks. These experiences were not reported to employers. Self-management of their pain through co-worker treatment, over-the-counter medications, or informal alteration in job tasks were reported as common.

CONCLUSION

Administrative injury records may underrepresent injuries among rehabilitation professionals. This may be due to their perception of work-related pain as something different than work-related injuries, or that many of these rehabilitation professionals treat their own work-related pain and symptoms rather than report them. To get a more accurate assessment of injury frequency among rehabilitation professionals, researchers should gather information directly from the participants, and should inquire about work-related pain in addition to injury.

A novel motorized office chair causes low-amplitude spinal movements and activates trunk muscles: A cross-over trial

INTRODUCTION

Inactivity and long periods of sitting are common in our society, even though they pose a health risk. Dynamic sitting is recommended to reduce this risk. The purpose of this study was to investigate the effect of continuous passive motion (CPM) conducted by a novel motorized office chair on lumbar lordosis and trunk muscle activation, oxygen uptake and attentional control.

STUDY DESIGN

Randomized, single-session, crossover with two periods/conditions.

METHODS

Twenty office workers (50% women) sat for one hour on the motorized chair, one half with CPM, the other not. The starting condition (CPM/no CPM) was switched in half of the sample. The participants were equipped with a spirometric cart, surface EMG, the Epionics SPINE system and performed a computer-based test for attentional control (AX-CPT). Outcomes were lumbar sagittal movements and posture, number of trunk muscle activations, attentional control and energy expenditure.

RESULTS

The CPM of the chair causes frequent low-amplitude changes in lumbar lordosis angle (moved: 498 ± 133 vs. static: 45 ± 38) and a higher number of muscle activations. A periodic movement pattern of the lumbar spine according to the movement of the chair was observed in every participant, although, sitting behavior varied highly between individuals. Attentional control was not altered in the moved condition (p = .495; d = .16). Further, oxygen uptake did not increase higher than 1.5 MET.

CONCLUSION

The effects of the motorized chair can be particularly useful for people with static sitting behavior. Further studies should investigate, whether CPM provides the assumed beneficial effects of dynamic sitting on the spine.

Evaluating cognitive and physical work performance: A comparative study of an active and passive industrial back-support exoskeleton

Occupational back-support exoskeletons, categorized as active or passive, hold promise for mitigating work-related musculoskeletal disorders. However, their impact on combined physical and cognitive aspects of industrial work performance remains inadequately understood, especially regarding potential differences between exoskeleton categories. A randomized, counterbalanced cross-over study was conducted, comparing the active CrayX, passive Paexo Back, and a no exoskeleton condition. A 15-min dual task was used to simulate both cognitive and physical aspects of industrial work performance. Cognitive workload parameters included reaction time, accuracy, and subjective measures. Physical workload included movement duration, segmented in three phases: (1) walking to and grabbing the box, (2) picking up, carrying, and putting down the box, and (3) returning to the starting point. Comfort of both devices was also surveyed. The Paexo significantly increased movement duration in the first segment compared to NoExo (Paexo = 1.55 ± 0.19 s; NoExo = 1.32 ± 0.17 s; p < .01). Moreover, both the Paexo and CrayX increased movement duration for the third segment compared to NoExo (CrayX = 1.70 ± 0.27 s; Paexo = 1.74 ± 0.27 s, NoExo = 1.54 ± 0.23 s; p < .01). No significant impact on cognitive outcomes was observed. Movement Time 2 was not significantly affected by both exoskeletons. Results of the first movement segment suggest the Paexo may hinder trunk bending, favoring the active device for dynamic movements. Both devices may have contributed to a higher workload as the movement duration in the third segment increased compared to NoExo.

Prevalence of Postural Changes and Musculoskeletal Disorders in Young Adults

BACKGROUND

Postural changes are considered a public health problem, especially those that affect the spine, as they may predispose to degenerative conditions of the spine in adulthood. Musculoskeletal disorders are the main cause of chronic pain, illness, reduced educational performance, productivity, and quality of life, and are responsible for increased absenteeism, which could compromise the future career of students. The purpose of this study was to identify the prevalence of postural changes and the occurrence of musculoskeletal disorders in different anatomical regions in the 12 months prior and 7 days prior to the application of the questionnaire and the number of affected anatomical regions.

METHODS

This is an observational, descriptive, cross-sectional study. It included 508 students selected by a stratified random sample. Our outcomes were the Portuguese version of the Standardized Nordic Musculoskeletal Questionnaire, the Adam's test, a scoliometer, and the visual analog pain scale associated with the Nordic Musculoskeletal Questionnaire.

RESULTS

In total, 79.3% of the students tested positive with the Adam's test. The neck, shoulder, lumbar region, and knee stood out in all of the temporal references, the 12 months prior (44.3%; 35.2%, 50.2%, 34.1%) and the 7 days prior (16.5%, 16.9%; 28.9%, 17.5%), and even in the restriction of activity due to painful symptoms in the 12 months prior (4.3%, 5.3%, 10.6%, 8.5%).

CONCLUSIONS

Out of 497 students, 403 were identified with postural changes. The high prevalence rate of identified musculoskeletal symptoms in the anatomical regions of the neck, lumbar region, and shoulder raises the need for intervention in students. Gender appears to generate differences between men and women. Pain from multiple body sites is frequent among young adults.

Wrist Extensor Muscle Fatigue During a Dual Task With Two Muscular and Cognitive Load Levels in Younger and Older Adults

OBJECTIVE

To examine the effect of concurrent physical and cognitive demands as well as age on indicators of muscle fatigue at the wrist.

BACKGROUND

There are few studies examining risk indicators for musculoskeletal disorders associated with work-related physical and cognitive demands that often occur simultaneously in the workplace.

METHODS

Twenty-four gender-balanced older and 24 gender-balanced younger (mean age 60 and 23 years) participants performed four 30 min dual tasks. Tasks differed by the muscular load level during force tracking: 5% and 10% of maximum voluntary contraction force (MVC) and concurrent cognitive demands on the working memory: easy and difficult. Muscle fatigue was assessed by MVC decline and changes in surface electromyography (increased root mean square: RMS, decreased median frequency: MF) at the extensor digitorum (ED) and extensor carpi ulnaris (EU).

RESULTS

A decline in MVC was found in all participants when tracking was performed at 10% MVC (mean ± SD: 137.9 ± 49.2 - 123.0 ± 45.3 N). Irrespective of age, muscular, or cognitive load, RMS increased (ED 12.3 ± 6.5 - 14.1 ± 7.0% MVE, EU 15.4 ± 7.6 - 16.9 ± 8.6% MVE) and MF decreased (ED 85.4 ± 13.6 - 83.2 ± 12.8 Hz, EU 107.2 ± 17.1 - 104.3 ± 16.7 Hz) in both muscles. However, changes in MF of EU tended to be more pronounced in the older group at higher cognitive and lower muscular load, without reaching statistical significance.

CONCLUSION

Maximum voluntary contraction indicated no interaction between muscle fatigue, cognitive load, or age. However, the tendencies toward altered muscle activity due to an increase in cognitive load and older age suggest muscular adaptations while maintaining tracking performance during the onset of fatigue signs in the sEMG signal.

APPLICATION

If the tendencies in muscle activity are confirmed by further studies, ergonomic assessments in industrial workplaces should consider cognitive load and age when describing the risk of musculoskeletal disorders.

'Wait…, let me tell you, if I worked for a boss, I would be on sick leave': A Qualitative Study of Self-Employed Workers in Physically Demanding Jobs in the Netherlands

PURPOSE

The purpose of this study was to explore the perspectives of self-employed workers with a physically demanding job on work participation.

METHODS

We interviewed self-employed workers with a physically demanding job, using semi-structured interviews, which were audio recorded. The main topic addressed was the workers' health in relation with their work participation, work demands, and preventive measures. The interviews were transcribed verbatim and coded by three team members of the research team in several steps. We used the consolidated criteria for reporting qualitative research (COREQ) checklist to report our findings.

RESULTS

We interviewed 18 self-employed workers: 83% male, 49 years (SD 7), self-employed for 18 years (SD 9) and the majority (n = 14) worked in the construction sector. Thematic analysis revealed facilitators and barriers for work participation across three main themes: personal factors, work factors, and healthcare. Personal factors compassed sub-themes such as health and financial consequences. Work factors included sub-themes related to work demands and adaptations and healthcare encompassed sub-themes associated with work-related care and medication.

CONCLUSION

To our knowledge, this is the first qualitative study that investigated the perspectives of self-employed workers in physically demanding jobs regarding work participation. While most facilitators and barriers were consistent with those described in the literature for employees, certain factors, such as financial consequences of ceasing work, emerged important factors for work participation among self-employed workers.

A Neuromechanical Model-Based Strategy to Estimate the Operator's Payload in Industrial Lifting Tasks

One of the main technological barriers hindering the development of active industrial exoskeleton is today represented by the lack of suitable payload estimation algorithms characterized by high accuracy and low calibration time. The knowledge of the payload enables exoskeletons to dynamically provide the required assistance to the user. This work proposes a payload estimation methodology based on personalized Electromyography-driven musculoskeletal models (pEMS) combined with a payload estimation method we called "delta torque" that allows the decoupling of payload dynamical properties from human dynamical properties. The contribution of this work lies in the conceptualization of such methodology and its validation considering human operators during industrial lifting tasks. With respect to existing solutions often based on machine learning, our methodology requires smaller training datasets and can better generalize across different payloads and tasks. The proposed payload estimation methodology has been validated on lifting tasks with 0kg, 5kg, 10kg and 15kg, resulting in an average MAE of about 1.4 Kg. Even if 5kg and 10Kg lifting tasks were out of the training set, the MAE related to these tasks are 1.6 kg and 1.1 kg, respectively, demonstrating the generalizing property of the proposed methodology. To the best of the authors' knowledge, this is the first time that an EMG-driven model-based approach is proposed for human payload estimation.

Validation of a modified visual analogue scale to measure user-perceived comfort of a lower-limb exoskeleton

User perceived exoskeleton comfort is likely important for device acceptance, but there is currently no validated instrument to measure it. The Visual Analogue Scale (VAS) is an existing tool to measure subjective human feedback by asking the user to mark a point on a line with each end of the line representing an opposing anchor statement. It can be modified to show the previous response, allowing the subject to directly indicate if the current condition is better or worse than the previous one. The goal of this study was to determine how well the modified VAS could measure user-perceived comfort as the exoskeleton control parameters were varied. To validate the survey, 14 healthy subjects walked in a pair of ankle exoskeletons with approximately ten distinct sets of control parameters tested in a prescribed order. Each set of control parameters was tested twice. After each trial, user-perceived comfort was measured using a two-question VAS survey. The repeatability coefficient was approximately 40 mm, similar to the total range of responses. The results were also inconsistent, with relative rankings between consecutive pairs of conditions matching for approximately 50% of comparisons. Thus, as tested, the VAS was not repeatable or consistent. It is possible that subject adaptation within the trial and over the course of the experiment may have impacted the results. Additional work is needed to develop a repeatable method to measure comfort and to determine how perceived comfort varies as subjects' gain exoskeleton experience.

Low Back Pain in Resident Doctors with Standardized Training in China: A Cross-Sectional Study

Background

Low back pain (LBP) is a prevalent occupational disease with high morbidity among healthcare workers. Since the implementation of standardized residency training in China in 2015, the training intensity has significantly increased, which may lead to a higher incidence of LBP. However, epidemiological studies on LBP among resident doctors with standardized training remain scarce.

Objective

To investigate the prevalence and associated factors of LBP among resident doctors with standardized training in a tertiary hospital in China.

Methods

A cross-sectional study was conducted using self-administered questionnaires to collect information on demographics, lifestyle factors, work-related factors, and LBP from 345 resident doctors. Descriptive statistics were used to analyze the prevalence of LBP. Logistic regression analysis was performed to identify factors associated with LBP.

Results

Among 345 participants, the 1-year prevalence of LBP was 75.9%. Multivariable analysis revealed that physical exercise, weekly working hours, and prolonged sitting were independent risk factors for LBP.

Conclusion

The prevalence of LBP among resident doctors was high. Promoting physical exercise, controlling working hours, and improving sitting posture may help prevent LBP. The study was limited by its cross-sectional design and self-reported data. Future studies should use longitudinal designs, objective measures, and larger and more representative samples to further explore the epidemiology and etiology of LBP among resident doctors with standardized training.