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Biomedical subjects

Allard J van der Beek

Publications and source records attributed to Allard J van der Beek.

At least 19 recordsLinked to original sources

The effect of joystick handle size and gain at two levels of required precision on performance and physical load on crane operators.

The study was designed to determine the effect of joystick handle size and (display-control) gain at two levels of required task precision on performance and physical load on crane operators. Eight experienced crane operators performed a simulated crane operation task on a computer by use of a joystick with either a short or a large handle. The task was performed at three gain levels and at two levels of required precision. Task performance, wrist and forearm postures, upper extremity muscle activity, perceived exertion and perceived comfort were measured.Task performance improved when using the joystick with the short handle and when working at a higher gain, while physical load decreased or remained the same. An increased level of required task precision was associated with a lower performance, but physical load was not affected. External validity of the simulated crane task seemed sufficient enough to extrapolate the results to practice.A joystick with a short handle is recommended, as this leads to an increased performance whilst the operator's physical load decreases or remains the same. Further optimization of performance and physical load can be achieved by optimizing gain settings of the joystick in relation to the task and type of joystick used.

Adult↗

Prospective research on musculoskeletal disorders in office workers (PROMO): study protocol.

BACKGROUND: This article describes the background and study design of the PROMO study (Prospective Research on Musculoskeletal disorders in Office workers). Few longitudinal studies have been performed to investigate the risk factors responsible for the incidence of hand, arm, shoulder and neck symptoms among office workers, given the observation that a large group of office workers might be at risk worldwide. Therefore, the PROMO study was designed. The main aim is to quantify the contribution of exposure to occupational computer use to the incidence of hand, arm, shoulder and neck symptoms. The results of this study might lead to more effective and/or cost-efficient preventive interventions among office workers. METHODS/DESIGN: A prospective cohort study is conducted, with a follow-up of 24 months. In total, 1821 participants filled out the first questionnaire (response rate of 74%). Data on exposure and outcome is collected using web-based self-reports. Outcome assessment takes place every three months during the follow-up period. Data on computer use are collected at baseline and continuously during follow-up using a software program. DISCUSSION: The advantages of the PROMO study include the long follow-up period, the repeated measurement of both exposure and outcome, and the objective measurement of the duration of computer use. In the PROMO study, hypotheses stemming from lab-based and field-based research will be investigated.

Arm Injuries↗

Is an imbalance between physical capacity and exposure to work-related physical factors associated with low-back, neck or shoulder pain?

OBJECTIVES: This study investigates whether an imbalance between physical capacity and exposure to work-related physical factors is associated with low-back, neck, or shoulder pain. METHODS: Data of the longitudinal study on musculoskeletal disorders, absenteeism, stress, and health (SMASH), with a follow-up of 3 years (N=1789), were used. At baseline, physical capacity (isokinetic lifting strength, static muscle endurance, and mobility of the spine) and exposure to work-related physical factors were assessed. During the follow-up, low-back, neck, and shoulder pain were self-reported annually. "Imbalance" was defined as lower than median capacity combined with higher than median exposure, "high balance" was high capacity and high exposure, and "low balance" was low capacity and low exposure. RESULTS: For both the low-back and neck, imbalance between static endurance and working with flexed postures was a risk factor for pain [relative risk (RR) 1.35, 95% confidence interval (95% CI) 1.08-1.68, and RR 1.36, 95% CI 0.96-1.91, respectively]. Low balance was also associated with low-back pain (RR 1.29, 95% CI 1.04-1.68). Furthermore, low balance between isokinetic lifting strength and lifting exposure was a risk factor for low-back and neck pain [RR between 1.22 (95% CI 0.99-1.49) and 1.35 (95% CI 1.03-1.79)]. No associations were found with shoulder pain. CONCLUSIONS: Some relationship between low-back and neck pain and combined measures of physical capacity with exposure to work-related physical factors seems to exist, but an imbalance between physical capacity and exposure was not found to yield higher risks than high balance or low balance.

Absenteeism↗

Work-related disease in general practice: a systematic review.

OBJECTIVES: The objective was to answer the following questions: What is the prevalence of potentially work-related diseases in the general practice population? What is the incidence of consulting a GP for a potentially work-related disease? What is the relationship between diseases seen in general practice and work ability? METHODS: Cochrane standards and QUOROM principals were used. For this systematic review the available literature was identified in a computerized search of the bibliographical databases Medline, Embase and Osh-rom. A total of 22 publications (24 studies) met the inclusion criteria. RESULTS: In the general practice population high prevalence rates of potentially work-related diseases were found for low back pain, neck pain and shoulder pain. Incidence rates of consulting a GP for a potentially work-related disease were high also. Musculoskeletal disorders were the main reasons for work-related consultations in general practice. Work-related diseases can affect work ability. CONCLUSIONS: Work-related diseases are common, given the high incidence and prevalence of potentially work-related diseases found in the general practice population and seen by the GP. This review underlines the important role of GPs in identifying and managing work-related diseases. GPs should consider the work factor and pay special attention to the effects of work on health, because patients often link their work with their illness.

Epidemiologic Methods↗

Psychosocial work characteristics in relation to neck and upper limb symptoms.

The aim of this study was to investigate the relationship between psychosocial work characteristics and neck and upper limb symptoms and to examine to what extent this relationship could be explained by other risk factors. Data were used from a prospective cohort study in a working population, with a follow-up period of 3 years. The 3-year cumulative incidence rates of neck or upper limb symptoms, neck/shoulder symptoms and elbow/wrist/hand symptoms were 32, 24 and 15%, respectively. After adjustment for potential confounders high job demands was identified as a risk factor for neck/shoulder symptoms (RR: 2.1; CI: 1.2-3.6) and elbow/wrist/hand symptoms (RR: 1.9; CI: 1.0-3.7), and low social support of co-workers was identified as a risk factor for elbow/wrist/hand symptoms (RR: 2.2; CI: 1.0-4.9). Partly, but not exclusively, these relationships were intermediated by an increased exposure to physical risk factors and increased stress symptoms. Personal characteristics did not considerably influence the main effects of the identified risk factors.

Cohort Studies↗

An evaluation of methods assessing the physical demands of manual lifting in scaffolding.

Four methods assessing the physical demands of manual lifting were compared. The scaffolding job was evaluated and three distinct scaffolding tasks were ranked using: (1) the revised NIOSH lifting equation (NIOSH method), (2) lifting guidelines for the Dutch construction industry (Arbouw method), (3) rapid appraisal of the NIOSH lifting equation (practitioners' method), and (4) systematic observations. For the three first-mentioned methods the same dataset was used; observation took place in a different setting in the same company. At job level, all methods indicated that ergonomic interventions are required to protect scaffolders from an increased risk for low back pain. The NIOSH, Arbouw and practitioners' method resulted in a similar ranking order of tasks (transport>construction>dismantlement). In contrast, the observational method gave transport the lowest ranking. The underlying cause was probably that the observational method is more sensitive to durations of tasks and lifting within tasks than the three other methods.

Adult↗

Effect of job rotation on need for recovery, musculoskeletal complaints, and sick leave due to musculoskeletal complaints: a prospective study among refuse collectors.

BACKGROUND: Job rotation might be an effective preventive measure to reduce the prevalence of musculoskeletal complaints, although its effect has not been yet established. The aim of the present study is to evaluate the effect of job rotation in refuse collecting on need for recovery, prevalence of musculoskeletal complaints, and sick leave due to musculoskeletal complaints. METHODS: A 1-year prospective study among refuse collectors was performed, using standardized questionnaires. Job rotation was performed between collecting two-wheeled containers and driving a refuse truck. The experimental groups of rotating refuse collectors at t(0) and t(1) (group R-R) and non-rotating refuse collectors at t(0) and rotating refuse collectors at t(1) (group NR-R) were compared with a reference group of non-rotating refuse collectors at t(0) and t(1) (group NR-NR). RESULTS: The adjusted need for recovery of group R-R was marginally significantly lower than need for recovery of the reference group. Groups R-R and NR-R had a more than two times higher risk for complaints of the low back than the reference group. No other significant results were found. CONCLUSIONS: Job rotation seemed to coincide with a reduced need for recovery and was associated with an increased risk of low back complaints. No effects were found on sick leave due to musculoskeletal complaints. The results might be influenced by the healthy worker selection effect in the reference group and its inverse in the rotating groups.

Adult↗

Gender differences in self-reported physical and psychosocial exposures in jobs with both female and male workers.

OBJECTIVE: The aim was to determine whether men and women with the same job are equally exposed to work-related physical and psychosocial risk factors for musculoskeletal complaints. METHODS: Men (n = 491) and women (n = 342) in 8 jobs with both female and male workers completed a questionnaire on exposure to work-related risk factors. Gender, job title, and potential confounders were included in the final statistical models. Separate analyses were performed for desk workers and assembly workers. RESULTS: For most risk factors gender differences in exposure were found. Among desk workers exposures were most often higher for women, which was the opposite for assembly workers. CONCLUSIONS: Although exposure assessment relied on self-report, it seems unlikely that gender differences in reporting behavior completely explained gender differences in exposure. Thus, gender differences in exposure are present within the same job.

Adult↗

Mechanical loading of the low back and shoulders during pushing and pulling activities.

The objective of this study was to quantify the mechanical load on the low back and shoulders during pushing and pulling in combination with three task constraints: the use of one or two hands, three cart weights, and two handle heights. The second objective was to explore the relation between the initial and sustained exerted forces and the mechanical load on the low back and shoulders. Detailed biomechanical models of the low back and shoulder joint were used to estimate mechanical loading. Using generalized estimating equations (GEE) the effects were quantified for exerted push/pull forces, net moments at the low back and shoulders, compressive and shear forces at the low back, and compressive forces at the glenohumeral joint. The results of this study appeared to be useful to estimate ergonomics consequences of interventions in the working constraints during pushing and pulling. Cart weight as well as handle height had a considerable effect on the mechanical load and it is recommended to maintain low cart weights and to push or pull at shoulder height. Initial and sustained exerted forces were not highly correlated with the mechanical load at the low back and shoulders within the studied range of the exerted forces.

Adult↗

Effect of job rotation on work demands, workload, and recovery of refuse truck drivers and collectors.

Job rotation is often advocated to reduce workload, but its efficacy has seldom been investigated. The aim of this study is to compare the work demands, workload, and recovery among truck driving, refuse collecting, and rotating between these two jobs, between days and during the day. Three teams of 3 employees each participated in this study. Work demands were assessed by systematic observation of tasks and activities. Workload was quantified by means of heart rate, oxygen uptake, subjective ratings, and urinary excretion rates of catecholamines. Recovery was quantified by excretion rates of catecholamines after work. Job rotation between driving and collecting is an effective measure to reduce physical workload as compared with collecting only and to decrease mental workload as compared with driving only. However, job rotation resulted in increased physical workload as compared with driving only. Job rotation did not increase mental workload as compared with collecting only. No effects were seen on recovery. No differences were found between rotating between days and during the day. Actual or potential applications of this research include the recommendation that before job rotation is introduced, its efficacy be determined in terms of well-chosen workload measures because a reduction in work demands does not directly imply a reduction in workload. Therefore, job rotation might be less effective than expected.

Adult↗

Physical activity for people with a disability: a conceptual model.

The promotion of a physically active lifestyle has become an important issue in health policy in first-world countries. A physically active lifestyle is accompanied by several fitness and health benefits. Individuals with a disability can particularly benefit from an active lifestyle: not only does it reduce the risk for secondary health problems, but all levels of functioning can be influenced positively. The objective of this article is to propose a conceptual model that describes the relationships between physical activity behaviour, its determinants and functioning of people with a disability. The literature was systematically searched for articles considering physical activity and disability, and models relating both topics were looked for in particular. No models were found relating physical activity behaviour, its determinants and functioning in people with a disability. Consequently, a new model, the Physical Activity for people with a Disability (PAD) model, was constructed based on existing models of disability and models of determinants of physical activity behaviour. The starting point was the new WHO Model of Functioning and Disability, part of the International Classification of Functioning, Disability and Health (ICF), which describes the multidimensional aspects of functioning and disability. Physical activity behaviour and its determinants were integrated into the ICF model. The factors determining physical activity were based mainly on those used in the Attitude, Social influence and self-Efficacy (ASE) model. The proposed model can be used as a theoretical framework for future interventions and research on physical activity promotion in the population of people with a disability. The model currently forms the theoretical basis for a large physical activity promotion trial in ten Dutch rehabilitation centres.

Attitude↗

Costs, benefits and effectiveness of worksite physical activity counseling from the employer's perspective.

OBJECTIVES: This study evaluated the impact of worksite physical activity counseling using cost-benefit and cost-effectiveness analyses. METHODS: Civil servants (N = 299) were randomly assigned to an intervention (N = 131) or control (N = 168) group for 9 months. The intervention costs were compared with the monetary benefits gained from reduced sick leave. In addition, the intervention costs minus the monetary benefits from sick leave reduction were compared with the effects (percentage meeting the public health recommendation for moderate-intensity physical activity, energy expenditure, cardiorespiratory fitness, and upper extremity symptoms). RESULTS: The intervention costs were EUR 430 per participant, and the benefits were EUR 125 due to sick leave during the intervention period, for net total costs of EUR 305 for the intervention. During the same 9-month period the year after the intervention, the benefits from sick leave reduction were EUR 635. No statistically significant differences in costs and benefits were found between the groups. As to the cost-effectiveness, improvement in energy expenditure and cardiorespiratory fitness was observed at higher costs. The point estimates of the cost-effectiveness ratios were EUR 5.2 (without imputation of effect data) and EUR 2.7 (with imputation of effect data) per extra kilocalorie of energy expenditure per day and EUR 235 (without imputation of effect data) and EUR 45.9 (with imputation of effect data) per beat per minute of decrease in submaximal heart rate. CONCLUSIONS: This study does not provide a financial reason for implementing worksite counseling intervention on physical activity on the short-term. However, positive effects were shown for energy expenditure and cardiorespiratory fitness.

Adult↗

Gender differences in the relations between work-related physical and psychosocial risk factors and musculoskeletal complaints.

Gender differences in the prevalence of musculoskeletal complaints might be explained by differences in the effect of exposure to work-related physical and psychosocial risk factors. A systematic review was conducted to examine gender differences in the relations between these risk factors and musculoskeletal complaints. Several electronic databases were searched. The strength of the evidence was determined on the basis of the methodological quality and consistency of the study results. For lifting, strong evidence was found that men have a higher risk of back complaints than women. The same was found for the relation between hand-arm vibration and neck-shoulder complaints. For arm posture, strong evidence was found that women have a higher risk of neck-shoulder complaints than men. For social support, no evidence of a gender difference was found for either neck-shoulder or back complaints. For hand-wrist and lower-extremity complaints, inconclusive evidence was found due to a lack of high-quality studies.

Evidence-Based Medicine↗

The effectiveness of worksite physical activity programs on physical activity, physical fitness, and health.

OBJECTIVE: To critically review the literature with respect to the effectiveness of worksite physical activity programs on physical activity, physical fitness, and health. DATA SOURCES: A search for relevant English-written papers published between 1980 and 2000 was conducted using MEDLINE, EMBASE, Sportdiscus, CINAHL, and Psychlit. The key words used involved a combination of concepts regarding type of study, study population, intervention, and outcome measure. In addition, a search was performed in our personal databases, as well as a reference search of the studies retrieved. STUDY SELECTION: The following criteria for inclusion were used: 1) randomized, controlled trial or nonrandomized, controlled trial; 2) working population; 3) worksite intervention program to promote employees' physical activity or physical fitness; and 4) physical activity, physical fitness, or health-related outcomes. DATA EXTRACTION: Two reviewers independently evaluated the quality of relevant studies using a predefined set of nine methodological criteria. Conclusions regarding the effectiveness of a worksite physical activity programs were based on a rating system consisting of five levels of evidence. DATA SYNTHESIS: Fifteen randomized, controlled trials and 11 nonrandomized, controlled trials met the criteria for inclusion and were reviewed. Six randomized, controlled trials and none of the nonrandomized, controlled trials were of high methodological quality. Strong evidence was found for a positive effect of a worksite physical activity program on physical activity and musculoskeletal disorders. Limited evidence was found for a positive effect on fatigue. For physical fitness, general health, blood serum lipids, and blood pressure, inconclusive or no evidence was found for a positive effect. CONCLUSIONS: To increase the level of physical activity and to reduce the risk of musculoskeletal disorders, we support implementation of worksite physical activity programs. For the other outcome measures, scientific evidence of the effectiveness of such a program is still limited or inconclusive, which is mainly the result of the small number of high-quality trials. Therefore, we recommend performing more randomized, controlled trials of high methodological quality, taking into account criteria such as randomization, blinding, and compliance.

Health Promotion↗

Episodes of low back pain: a proposal for uniform definitions to be used in research.

STUDY DESIGN: Literature review and group discussions. OBJECTIVE: To propose uniform definitions for low back pain episodes to be used in research. BACKGROUND: Different definitions of episodes have been used in low back pain studies. This hampers comparison of study results. Definitions are proposed for episodes of low back pain, care for low back pain, and work absence because of low back pain. METHODS: In a Medline search, we identified about 1200 papers, of which 81 possibly contained a definition of episodes. In group discussions, we decided which definitions to propose and discussed their applicability. RESULTS: We found few definitions in the literature. In the group discussions we decided to define an episode of LBP as a period of pain in the lower back lasting for more than 24 hours, preceded and followed by a period of at least 1 month without low back pain. An episode of care for low back pain was defined as a consultation or a series of consultations for low back pain, preceded and followed by at least 3 months without consultation for low back pain. An episode of work absence due to low back pain was defined as a period of work absence due to low back pain, preceded and followed by a period of at least 1 day at work. CONCLUSIONS: In many studies, episodes of low back pain are mentioned without a clear definition. We consider our proposed definitions of episodes to be arbitrary but well considered. We advise that they be tested for use in future research.

Absenteeism↗

Evaluation of ergonomic adjustments of catering carts to reduce external pushing forces.

An existing standard catering cart was compared with two prototypes for pushbar and castor design. The first objective of this study was to find out which cart was accompanied with the lowest manually exerted external forces in pushing in a straight way and in pushing a 90 turn. The second objective was to explore effects of the pushbar and castor design of the carts. In the initial and ending phase, the prototypes were accompanied with higher exerted forces compared with the standard catering cart. In pushing straight. the reversed start position of the bigger castors of the prototypes hampered a fluent acceleration and caused higher initial forces. In decelerating, the lower rolling friction of the bigger castors required higher forces to stop the prototypes compared to the standard cart. During the sustained phase, the prototype carts were more favourable. Effects of pushbar and castor design were studied during a turn. The vertical pushbars of the prototypes resulted in lower time-integrated pushing forces. Providing an axis of rotation for turning activities by means of a fixed wheel was proven to be advantageous.

Adult↗

Effect of the number of two-wheeled containers at a gathering point on the energetic workload and work efficiency in refuse collecting.

The effect of the number of two-wheeled containers at a gathering point on the energetic workload and the work efficiency in refuse collecting was studied in order to design an optimal gathering point for two-wheeled containers. Three sizes of gathering points were investigated, i.e. with 2, 16 and 32 two-wheeled containers at a gathering point. The collecting of two-wheeled containers was simulated in a test circuit. The energetic workload was quantified by the parameters oxygen uptake (1 min(-1)), heart rate (beats min(-1)) and perceived exertion. The work efficiency was quantified as the time it took to collect 32 two-wheeled containers per time period. The maximum acceptable amount of two-wheeled containers collected during an 8-h working day was estimated using the energetic criterion of a maximum oxygen uptake of 30% VO2max. The size of the gathering point had no effect on the oxygen uptake, heart rate or perceived exertion. However, the number of two-wheeled containers per collecting period (work efficiency) and the maximum acceptable amount during an 8-h working day were higher in the conditions with 16 and 32 two-wheeled containers at a gathering point compared to the condition with the 2 two-wheeled containers at a gathering point.

Adult↗