Epidemiological and biomechanical evaluation of airline baggage handling

Objectives. Musculoskeletal disorders (MSDs) are prevalent among airline baggage handlers due to manual materials handling. In this study, the Nordic musculoskeletal questionnaire (NMQ), the revised National Institute for Occupational Safety and Health (NIOSH) lifting equation, and the University of Michigan 3D Static Strength Prediction Program? (3DSSPP) were used to analyze MSDs among baggage handlers. Methods. The NMQ was filled out by 209 baggage handlers and 46 arbitrarily selected baggage handlers were evaluated using the NIOSH method and 3DSSPP. Results. The obtained results showed that the most common MSDs occurred in the lower back region. The next risky regions included knees, neck, and upper back, respectively. The NIOSH results confirmed that the subjects lifted loads heavier than the permitted limit and their lifting postures were inappropriate. The results of the 3DSSPP also indicated that compression forces exceeded the NIOSH limit in these awkward postures. Conclusions. Relying on this study, holding compulsory ergonomic lifting training courses could be proposed for workers and regulations adjusting an upper limit for maximum baggage weight must be also enacted in order to improve occupational health and prevent the prevalence of increasing MSDs.     

Effects of Manual Handling,Posture, and Whole Body Vibrations on Low-Back Pain

To determine the effect of occupational stress on low-back pain (LBP), a cross-sectional study has been carried out, by interviews, on workers exposed to 3 stresses: manual handling (MH, 82 women and 264 men), whole body vibrations (WBV, 274 men), and static postures (278 women). Anthropometric data, occupational stress, LBP severity and frequency, and a psychological evaluation of these groups were compared to those of a control population of 208 workers (104 men and 104 women).

The results show that 30% of the population had never suffered from LBP. Age and the body mass index of the workers were the parameters most closely associated with LBP. Women involved in MH had higher frequency and severity of LBP than their reference population. Men involved in MH or exposed to WBV had higher frequency of painful episodes than their reference population. Workers exposed to one of the stresses were on sick leave for LBP more often, and for longer periods, than workers in the reference group. The results show that individual factors are often decisive in the onset of LBP. Nevertheless, in the more serious LBP cases, occupational stress is an aggravating factor for LBP and its consequences.     

Manual Material Handling Assessment Among Workers of Iranian Casting Workshops

Manual material handling (MMH) tasks can be found in most workplaces and they may constitute a risk factor for work-related musculoskeletal disorders (WMSDs). This study was conducted to determine the prevalence of WMSDs and to compare MMH loads with the acceptable weight and force limits among Iranian casting workers. Data were collected from 50 workers of casting workshops who performed MMH tasks. The Nordic musculoskeletal disorders questionnaire and the Snook tables were used as tools for data collection. Hand/ wrist symptoms were the most prevalent problems among the workers (84%). The results of the Snook tables showed that the loads in lifting (84%), lowering (86%), carrying (66%), pushing with initial (43%) and sustained force (59%), and pulling tasks with initial (48%) and sustained force (93%) exceeded recommended limits. WMSDs occurred in high rates among the workers and, thus, ergonomics interventions should focus on decreasing WMSDs and redesigning MMH tasks.     

Impact of posture and upper-limb muscle activity on grip strength

Purpose. The current research was carried out to determine grip strength (GS) with change in posture and upper-limb muscle activity of manual workers and investigate the impacts of these changes. Methods. For the current research, 120 male and 80 female participants were selected and GS was assessed using a digital hand grip dynamometer in various conditions. Results. The outcomes showed that male participants had higher GS as compared to female participants. Maximum GS was found in a standing posture with the fixed forward shoulder at 45°, elbow at 90° and a neutral position of the wrist and forearm for all participants. Conclusions. Higher values of GS were attained in standing postures which may result in attainment of higher performance levels by the workers. The outcomes justify the importance of correct postures during manual work in industries employing traditional methods.     

Relationship between musculoskeletal disorders and anthropometric indices among bus drivers in Zahedan city

Introduction. Most work-related musculoskeletal disorders (MSDs) are associated with improper postures and poorly designed workstations. This study is an attempt to examine the prevalence and severity of MSDs as well as anthropometric dimensions among city bus drivers. Methodology. This cross-sectional study was carried out on 60 male bus drivers. A body discomfort chart was used to evaluate MSDs. Spearman correlation was employed to examine the relationship between body size and the severity of discomfort. Results. Data analysis showed that discomfort reported in the lower back (33.3%), upper back (18.3%) and knee (15%) was severe and there was a direct and significant correlation between the body mass index and the severity of discomfort in the shoulder, arm and hip (p?p?Conclusion. The results of the study can be used to address ergonomic risk factors and reduce their associated disorders. The findings of the study can be used in training programs to educate drivers how to decrease the risk associated with work-related MSDs by adopting appropriate behavior strategies.     

An evaluation of Manutention training in preventing back strain and resultant injuries in nurses

As the number of manual handling injuries in carers and nurses continues to be very high, the problem of how to prevent injury has not been solved. Despite the obvious need for optimum working environments, the literature does not really support that an ergonomics or systems approach solves the injury problem. Similarly, the evidence for training as a preventive strategy is equivocal, although clearly people handling requires trained handlers for both their own and the patient's safety. This research aimed to evaluate the outcomes of training in a method of manual handling of people, Dotte's Manutention method, which claims to decrease back strain and effort in carers. The study evaluated handling techniques and injury outcomes of a group of nurses in a nursing home trained in this method, using two other homes as comparisons. The study hypothesized that training in the Manutention method would decrease back strain and resultant back injuries in nurses working in geriatric care. The results showed a clear pattern of declining incidence of nurses' back pain for the nurses trained in Manutention and increasing incidence in the other two homes. These findings approached significance with a probability of < 0.1. Of those respondents who indicated a decrease in pain during the twelve month research period, all attributed it to their training. Ninety four percent of respondents who received training agreed it made their manual handling job easier. The observation method used was not sensitive enough to evaluate the multiple movements involved in a patient transfer. A supplementary controlled study was performed using videotaping and the Ovako Working Assessment System (OWAS). Manutention lifts were rated significantly better than non-Manutention on the critical variable of working posture (p < 0.01) and observed effort (p < 0.05). Accident statistics on patient handling did not show decreased injury rates at twelve months. The difficulties of controlling variables in the workplace and of the measurement of complex handling tasks were limitations of this study.     

Occupational interventions for the prevention of back pain: Overview of systematic reviews

IntroductionWe conducted an overview of systematic reviews of interventions for the prevention of low back pain (LBP) that can be conducted in a workplace setting.MethodsAn electronic literature search was performed in Medline, EMBASE, and the Cochrane Library. Published peer-reviewed systematic reviews and meta-analyses, which described interventions for the primary or secondary prevention of LBP applicable to a workplace setting, were eligible for inclusion. The methodological quality of the included systematic reviews was assessed with the AMSTAR tool. The primary outcome of interest was the incidence of LBP; secondary outcomes were LBP-associated absenteeism, activity interference, and costs related to LBP.ResultsTwenty-eight eligible articles published between 1994 and 2016 were included in a qualitative synthesis following our screening of abstracts and full-text articles. The AMSTAR rating revealed 14 reviews of high, 10 of moderate, and 4 of low methodological quality. The identified interventions included workplace modifications (6 reviews, 10 studies, 6,751 subjects); shoe insoles (4 reviews, 6 studies, 2,356 subjects); and lumbar supports and other assistive devices (15 reviews, 18 studies, 60,678 subjects). Educational interventions investigated were back schools (10 reviews, 30 studies, 9,973 subjects); manual material handling techniques/advice (6 reviews, 24 studies, 10,505 subjects); and other forms of instruction including pamphlets, booklets, and other media (four reviews, 14 studies, 11,991 subjects). Exercise interventions, investigated in 12 reviews (35 studies, 19,330 subjects), showed moderate quality evidence of effectiveness for exercise interventions alone or in conjunction with educational interventions; no other type of intervention was consistently effective in the prevention of LBP or LBP-associated outcomes of interest.ConclusionsOur overview provides evidence of effectiveness for exercise with or without educational interventions in the prevention of LBP.Practical applicationsExercise interventions with or without educational interventions that can be applied in the workplace have the potential to prevent LBP.     

Driver’s mental workload prediction model based on physiological indices

Developing an early warning model to predict the driver’s mental workload (MWL) is critical and helpful, especially for new or less experienced drivers. The present study aims to investigate the correlation between new drivers’ MWL and their work performance, regarding the number of errors. Additionally, the group method of data handling is used to establish the driver’s MWL predictive model based on subjective rating (NASA task load index [NASA-TLX]) and six physiological indices. The results indicate that the NASA-TLX and the number of errors are positively correlated, and the predictive model shows the validity of the proposed model with an R² value of 0.745. The proposed model is expected to provide a reference value for the new drivers of their MWL by providing the physiological indices, and the driving lesson plans can be proposed to sustain an appropriate MWL as well as improve the driver’s work performance.     

Variation in posture quality across musical instruments and its impact during performances

Objective. Bad posture increases the risk that a musician may suffer from musculoskeletal disorders. This study compared posture quality required by different instruments or families of instruments. Methods. Using an ad-hoc postural observation instrument embracing 11 postural variables, four experts evaluated the postures of 100 students attending a Spanish higher conservatory of music. Results. The agreement of the experts’ evaluations was statistically confirmed by a Cohen's κ value between 0.855 and 1.000 and a Kendall value between 0.709 and 1.000 (p?χ² tests revealed significant association between instrument families and seated posture with respect to pelvic attitude, dorsal curvature and head alignment in both sagittal and frontal planes. This analysis also showed an association between instrument families and standing posture with respect to the frontal plane of the axis of gravity, pelvic attitude, head alignment in the frontal plane, the sagittal plane of the shoulders and overall posture. Conclusions. While certain postural defects appear to be common to all families of instruments, others are more characteristic of some families than others. The instrument associated with the best posture quality was the bagpipe, followed by percussion and strings.     

Cervical musculoskeletal disorders and their relationships with personal and work-related factors among electronic assembly workers

IntroductionElectronics assembly workers are reported to have a high prevalence of musculoskeletal disorders (MSDs). This study investigated the prevalence of cervical MSDs and the complex relationships between cervical MSDs and individual, physical, psychosocial factors among electronics assembly workers. Methods: In this cross-sectional survey, self-administered questionnaires from 700 workers in electronics manufacturing workshops were analysed. Information concerning musculoskeletal symptoms, personal and work-related factors was collected. Finally, the prevalence of cervical MSDs was computed for different subgroups, and the relationships with different factors were analyzed using logistic regression and structural equation modeling (SEM). Results: The total 12 month prevalence of cervical MSDs among the survey population was 29.4%. Variables of gender, job tenure, twisting head frequently, neck flexion/extension for long time and work required to be done quickly showed significant associations with MSDs in a multivariate logistic regression (P < 0.05). The SEM analysis showed moderate and significant correlations between postural load (γ = 0.279), gender (γ = 0.233) and cervical MSDs, while there were weak but significant correlations between vibration (γ = 0.024), work stress (γ = 0.126), job tenure (γ = 0.024) and cervical MSDs. Both work stress and vibration affected the MSDs indirectly through postural load. Conclusions: The logistic regression results support previous general epidemiological MSD studies, and indicates that individual, physical, and psychosocial factors are related to cervical MSDs. The SEM provides a better approximation of the complexity of the relationship between risk factors and cervical MSDs. Improving awkward postures may be effective ways to control the influence of occupational stressors or vibration on MSDs. Practical Applications: The study is to improve prevention of MSDs among electronics assembly workers and promote their occupational health.     

Integrated Estimation of the Effect of Physical Factors on Human Functional State During Mental Work

The purpose of this study was to develop a model for an integrated estimation of the functional state of the human organism (FSHO) and an integral estimation of physical factors (PF) for hygienic rating. Tests were performed twice with 3 men in 0.7-clo clothing during 4-hr mental work with 9 combinations of 4 PF: wideband noise (55–83 dB(A)), whole-body vibration (6 Hz, a_z = 0.2–1.8 ms^?2), air temperature (18–30 °C), and illumination (1, 3, 5 lx). Thermoregulatory, cardiovascular, and psychophysiological reactions and temporary threshold of hearing (TTS₂) shifts were studied. For the integral estimation of PF influence on FSHO the model F(y₁, y₂, ... y_m) = f(x₁, x₂, ... x_n) was used, relating both FSHO and PF sets. The most important physiological parameters in creating FSHO are defined and the contribution of individual parameters of FSHO and PF is found.     

Physical limitations and musculoskeletal complaints associated with work in unusual or restricted postures: a literature review

INTRODUCTION: The vast majority of ergonomics research has addressed the demands of work in standing or sitting postures, and understandably so. However, many workers (e.g., underground miners, aircraft baggage handlers, plumbers, agricultural workers, mechanics, and others) are often required to adopt postures such as kneeling, stooping, squatting, or lying down for significant periods of the workday. METHOD: A literature search was performed using the ISI Web of Science database (for years 1980-2004). Articles retrieved from this search were evaluated in terms of relevance to assessing physical capabilities of workers in these postures and/or the musculoskeletal epidemiology associated with these postures. RESULTS: Work in unusual and restricted postures was associated with significantly higher rates of musculoskeletal complaints compared to workers not adopting these postures in epidemiology studies (Odds Ratios ranging from 1.13 to 13). Some studies suggested a dose-response relationship, with longer exposures leading to increased musculoskeletal complaints. Physical strength and psychophysical lifting capacity vary significantly as unusual or restricted postures are adopted, with lower lifting capacities evident in the kneeling, squatting, and lying positions. CONCLUSIONS: Workers who adopt unusual or restricted postures appear to be at higher risk of musculoskeletal complaints and often exhibit reduced strength and lifting capacity. Research needs in this area include improved exposure assessment tools, studies of intervention effectiveness, adaptations of the body in response of work in unusual postures, and elucidation of relevant injury pathways. IMPACT ON INDUSTRY: Workers who adopt unusual or restricted postures in their work often experience higher musculoskeletal injury rates. If awkward postures cannot be eliminated in the workplace, jobs should be designed in accordance with the reduced strength and lifting capabilities observed in these postures.     

Knowledge,attitudes and practices of occupational risks in Colombian taxi drivers

Objective. The objective of this study was to learn about the health and safety strategies in a sample of taxi drivers in Bucaramanga, Colombia. Methods. A cross-sectional study was conducted among 138 taxi drivers. A survey was used to identify the socio-demographic and working characteristics, knowledge, attitudes and practices according to their occupational risk. Results. Eighty-five percent of the workers labored 9–15?h/day. Of those who suffered accidents, 27% were not affiliated to an occupational risk administrator (p = 0.028). Of the workers who had a work-related accident, 58% considered that the use of a cell phone while driving would not always reduce their attention, 50% always used their seat belt and 7% took active breaks and wore their seat belt (p = 0.01). Conclusions. Within this group of taxi drivers, having or believing to possess knowledge regarding an occupational risk did not ensure that they had a safe attitude or safe working practices.     

Brake reactions of distracted drivers to pedestrian Forward Collision Warning systems

Introduction: Forward Collision Warning (FCW) can be effective in directing driver attention towards a conflict and thereby aid in preventing or mitigating collisions. FCW systems aiming at pedestrian protection have been introduced onto the market, yet an assessment of their safety benefits depends on the accurate modeling of driver reactions when the system is activated. This study contributes by quantifying brake reaction time and brake behavior (deceleration levels and jerk) to compare the effectiveness of an audio-visual warning only, an added haptic brake pulse warning, and an added Head-Up Display in reducing the frequency of collisions with pedestrians. Further, this study provides a detailed data set suited for the design of assessment methods for car-to-pedestrian FCW systems. Method: Brake response characteristics were measured for heavily distracted drivers who were subjected to a single FCW event in a high-fidelity driving simulator. The drivers maintained a self-regulated speed of 30 km/h in an urban area, with gaze direction diverted from the forward roadway by a secondary task. Results: Collision rates and brake reaction times differed significantly across FCW settings. Brake pulse warnings resulted in the lowest number of collisions and the shortest brake reaction times (mean 0.8 s, SD 0.29 s). Brake jerk and deceleration were independent of warning type. Ninety percent of drivers exceeded a maximum deceleration of 3.6 m/s² and a jerk of 5.3 m/s³. Conclusions: Brake pulse warning was the most effective FCW interface for preventing collisions. In addition, this study presents the data required for driver modeling for car-to-pedestrian FCW similar to Euro NCAP's 2015 car-to-car FCW assessment. Practical applications: Vehicle manufacturers should consider the introduction of brake pulse warnings to their FCW systems. Euro NCAP could introduce an assessment that quantifies the safety benefits of pedestrian FCW systems and thereby aid the proliferation of effective systems.     

Child passengers and driver culpability in fatal crashes by driver gender

Objective: Studies based on accident statistics generally suggest that the presence of a passenger reduces adult drivers' accident risk. However, passengers have been reported to be a source of distraction in a remarkable portion of distraction-related crashes. Although the effect of passengers on driving performance has been studied extensively, few studies have focused on how a child passenger affects the driver.

?A child in a car is a potential distractor for parents, especially for mothers of small children, who often suffer from sleep deficit. The aim of this study was to examine how the presence of child passengers of different ages is associated with a higher driver culpability, which was expected due to child-related distraction and fatigue.

Methods: The analysis was based on the comprehensive data of fatal crashes studied in-depth by multidisciplinary road accident investigation teams in Finland during 1988–2012. Teams determine the primary party who had the most crucial effect on the origin of the event. We define the primary party as culpable and the others involved as nonculpable drivers. The culpability rate was defined as the percentage of culpable drivers and rates were compared for drivers with a child/teen passenger aged 0–17 years (N = 348), with an adult passenger without children (N = 324), and when driving alone (N = 579), grouped by child age and driver gender.

?Drivers with specific risk-related behavior (substantial speeding, driving when intoxicated, unbelted, or without a license) were excluded from the analyses, in order to make the drivers with and without children comparable. Only drivers 26–47 years old were included, representing parents with children 0–9 years of age.

Results: Male drivers were less often culpable with 0- to 17-year-old passengers in the car than alone or with adults. This was not the case with female drivers. The gender difference in culpability was most marked with small children age 0–4 years. Female drivers' culpability rate with a 0- to 4-year-old child passenger was higher and male drivers' culpability rate was lower compared to drivers without passengers or with only adult passengers.

Conclusion: The results indicate that female drivers are at higher risk of crashes than male drivers when driving with small children. Further research is needed to replicate this finding and to determine causal mechanisms.     

The influence of axle position and the use of accessories on the activity of upper limb muscles during manual wheelchair propulsion

Introduction. Wheelchair configuration is an important factor influencing the ergonomics of the user–device interface and, from a biomechanical point of view, small changes in chair setup may have a positive influence on the demand on the upper limbs during manual propulsion. This study aimed to investigate the influence of the position of the rear wheels’ axle and the use of accessories on the activity of upper limb muscles during manual wheelchair propulsion. Methods. Electromyography signals of the biceps, triceps, anterior deltoids and pectoralis major were collected for 11 able-bodied subjects in a wheelchair propulsion protocol with four different wheelchair configurations (differing in axle position and the use of accessories) on a straightforward sprint and a slalom course. Results. With accessories, moving the axle forward led to a decrease in the activity of all muscles in both the straightforward sprint (significant differences in triceps, anterior deltoids and biceps) and the slalom course (significant difference in anterior deltoids and biceps). However, when propelling the chair without accessories, no difference was found related to axle position. Conclusion. Changes in wheelchair configuration can influence the ergonomics of manual wheelchair propulsion. Reducing the biomechanical loads may benefit users’ mobility, independence and social participation.     

Comparisons of ergonomic evaluation tools (ALLA,RULA, REBA and OWAS) for farm work

Introduction. The purpose of this study was to validate the agricultural lower limb assessment (ALLA) ergonomic checklist, which was developed for various agricultural tasks in Korea. Methods. One hundred and ninety-six working postures were selected from the real agricultural tasks to verify ALLA, a lower limb body posture assessment tool, and then evaluated by 16 ergonomic experts. Hit rate, quadratic weighted κ, one-way analysis of variance and t-test analyses were applied to compare ALLA with other assessment tools. Results. ALLA analysis had a superior hit rate with ergonomic expert assessment compared with other assessment tools. Quadratic weighted κ analysis also showed that ALLA provided superior estimates of risk levels for farm working postures. Discussion. ALLA would be an appropriate assessment tool to estimate risk factors for various lower limb body postures which frequently occur in agricultural tasks in Korea. ALLA is a simple and accurate risk assessment tool that could be usefully applied to identify and mitigate risk factors and work-related musculoskeletal disorders in agricultural tasks, and also to evaluate the effects of control and intervention for working conditions.