Documents Fallentin, Nils 9 results

Objectives A program called the Project on Research and Intervention in Monotonous Work (PRIM) was initiated in 1994 as a prospective cohort study of work-related musculoskeletal disorders. The group-based exposure assessment strategy, focusing on task-related exposure and used to obtain baseline measures of physical exposures, is reported in this paper.Methods Monotonous, repetitive worktasks were evaluated at 19 factories. Tasks with an estimated similarity in physical exposure were aggregated before 103 exposure groups were formed. Subjects from the exposure groups were randomly sampled for measurements, and task-related exposure levels were quantified by 43 single exposure items using a real-time video-based observation method that allowed computerized estimates of repetitiveness, body postures, force, and velocity. In combination with questionnaire-based data on task distribution, the duration of exposure was calculated at the individual level.Results The video-based observational method and the large number of exposure variables enabled the establishment of detailed quantitative exposure profiles in 103 task-based exposure groups. However, methodological problems associated with the use of grouped exposure assessment were revealed. Despite efforts to optimize group homogeneity, the within-group variance was larger than the between-group variance for several shoulder postural variables.Conclusions A task-based exposure-assessment strategy can be successful in solving some of the main problems associated with the assessment of physical workplace exposures. The large within-group variance in exposure to nonneutral shoulder postures may eventually require individual assessment or the inclusion of groups with maximal contrast in exposure or both.

"Objectives This prospective cohort study investigates work-related risk factors for occupational back injury among healthcare workers. Methods The study comprised 5017 female healthcare workers in eldercare from 36 municipalities in Denmark who responded to a baseline and follow-up questionnaire in 2005 and 2006, respectively. Using logistic regression, the odds for occupational back injury (ie, sudden onset episodes) in 2006 from patient transfers in 2005 was modeled. Results In the total study population, 3.9% experienced back injury during follow-up, of which 0.5% were recurrent events. When adjusting for lifestyle (body mass index, leisure-time physical activity, smoking), work-related characteristics (seniority and perceived influence at work), and history of back pain and injury, daily patient transfers increased the risk for back injury (trend, P=0.03): odds ratio (OR) 1.75 [95% confidence interval (95% CI) 1.05–2.93] for 1–2 transfers per day, OR 1.81 (95% CI 1.14–2.85) for 3–10 transfers per day, and OR 1.56 (95% CI 0.96–2.54) for >10 transfers per day, referencing those with <1 patient transfer on average per day. The population attributable fraction of daily patient transfer for back injury was estimated to be 36%. Among those with daily patient transfer (N=3820), using an assistive device decreased the risk for back injury for “often” and “very often” use [OR 0.59 (95% CI 0.36–0.98) and OR 0.62 (95% CI 0.38–1.00), respectively] referencing those who “seldom” use assistive devices. Conclusion Daily patient transfer was associated with increased risk for back injury among healthcare workers. Persistent use of an assistive device was associated with reduced risk for back injury among healthcare workers with daily patient transfers."

"Pain in the neck and upper extremity is reported with high frequency in repetitive work. Mechanical overload of soft tissues seems a plausible mechanism, but psychological factors have received considerable attention during the past decade. If psychological factors are important for development of regional pain in repetitive work, stress symptoms would likely be on the causal path.
AIMS:
To examine whether objective measures of repetitive monotonous work are related to occurrence and development of stress symptoms.
METHODS:
In 1994-95, 2033 unskilled workers with continuous repetitive work and 813 workers with varied work were enrolled. Measures of repetitiveness and force requirements were quantified using video observations to obtain individual exposure estimates. Stress symptoms were recorded at baseline and after approximately one, two, and three years by the Setterlind Stress Profile Inventory.
RESULTS:
Repetitive work, task cycle time, and quantified measures of repetitive upper extremity movements including force requirements were not related to occurrence of stress symptoms at baseline or development of stress symptoms during three years of follow up.
CONCLUSIONS:
The findings do not indicate that repetitive work is associated with stress symptoms, but small effects cannot be ruled out. Thus the results question the importance of mental stress mechanisms in the causation of regional pain related to repetitive work. However, the findings should be interpreted with caution because the stress inventory has not been validated against a gold standard."

"To evaluate the effect of individual characteristics and physical and psychosocial workplace factors on neck/shoulder pain with pressure tenderness in the muscles. SUMMARY OF BACKGROUND DATA: Controversy prevails about the importance of workplace factors versus individual factors in the etiology of pain in the neck and/or shoulders. METHODS: Study participants were 3123 workers from 19 plants. Physical risk factors were evaluated via video observations, and psychosocial risk factors were assessed with the job content questionnaire. Other procedures included symptom survey, clinical examination, and assessment of health-related quality of life (SF-36). The main outcome variable, neck/shoulder pain with pressure tenderness, was defined on the basis of subjective pain score and pressure tenderness in muscles of the neck/shoulder region. CONCLUSIONS: Work-related physical and psychosocial factors, as well as several individual risk factors, are important in the understanding of neck/shoulder pain. The findings suggest that neck/shoulder pain has a multifactorial nature. Reduced health-related quality of life is associated with subjective pain and clinical signs from the neck and shoulders. The physical workplace factors were highly intercorrelated, and so the effect of individual physical exposures could only be disentangled to a minor degree."

"Motor unit recruitment patterns were studied during prolonged isometric contraction using fine wire electrodes. Single motor unit potentials were recorded from the brachial biceps muscle of eight male subjects, during isometric endurance experiments conducted at relative workloads corresponding to 10% and 40% of maximal voluntary contraction (MVC), respectively. The recordings from the 10% MVC experiment demonstrated a characteristic time-dependent recruitment. As the contraction progressed both the mean number of motor unit spikes counted and the mean amplitude of the spikes increased significantly (P < 0.01). This progressive increase in spike activity was the result of a discontinuous process with periods of increasing and decreasing activity. The phenomenon in which newly recruited motor units replace previously active units is termed "motor unit rotation" and appeared to be an important characteristic of motor control during a prolonged low level contraction. In contrast to the 10% MVC experiment, there was no indication of de novo recruitment in the 40% MVC experiment. Near the point of exhaustion a marked change in action potential shape and duration dominated the recordings. These findings demonstrate a conspicuous difference in the patterns of motor unit recruitment during a 10% and a 40% MVC sustained contraction. It is suggested that there is a close relationship between intrinsic muscle properties and central nervous system recruitment strategies which is entirely different in fatiguing high and low level isometric"

"The report provides some support for the view that regulatory actions against work-related musculoskeletal disorders will be the most successful if an integrated ergonomic program approach is adapted. A substantial number of case studies indicates that ergonomic programs can be efficient in protecting workers against work-related musculoskeletal disorders. The General Accounting Office (GAO) study of several companies with ergonomic programs in the United States gives strong - although indirect - support for the belief that well-managed ergonomic programs with high commitment on the part of stakeholders can be efficient.
Contents:
accuracy, acute overload, adequacy, aged, back injury, carrying, decline, denmark, display screen equipment, effectiveness, energy consumption, energy expenditure, environmental disease process, equation for design and evaluation, ergonomic program management, ergonomic standards, ergonomics program, ergonomics requirements, ergonomics rule, evaluation criteria, evaluation, exposure assessment, finland, force limits, force, guidelines for practitioners, guidelines, hand activity level, hand-transmitted vibration, health requirements, historical perspective, human exposure, identification of risk factors, job design, lifting, machinery ergonomics, machinery operation, manual handling, manual lifting tasks, manual materials handling, maximal aerobic capacity, mechanical shock, mechanical vibration, monotonous, repetitive work, musculoskeletal disorders, niosh lifting equation, nordic perspective, norway, physical workload, posture, process-type standards, quantitative standards, reduction of adverse health effects, reduction of exposure, repetition, repetitive motion injuries, repetitive work, risk exposure assessment, risk factors, safety requirements, scientific coherency, shoulder-neck complaints, slip and fall injuries, standards, sweden, threshold limit values, upper extremities, upper extremity, upper-limb repetitive movements, usability, whole-body vibration, vibration standards, vibration, work postures, workers, workload, work-related cumulating trauma disorder, work-related musculoskeletal disorders ..."