The nature of work-related neck and upper limb musculoskeletal disorders

The nature of work-related musculoskeletal disorders of the neck and upper limbs is reviewed using both scientific data and the consensus view of experts, union bodies and government agencies across the European Union. Work-related musculoskeletal disorders describe a wide range of inflammatory and degenerative diseases and disorders. These conditions result in pain and functional impairment and may affect, besides others, the neck, shoulders, elbows, forearms, wrists and hands. They are work-related when the work activities and work conditions significantly contribute to their development or exacerbation but are not necessarily the sole determinant of causation. The classification and the need for standardised diagnostic methods for assessment of neck and upper limb musculoskeletal disorders are reviewed. These disorders are a significant problem within the European Union with respect to ill health, productivity and associated costs. The pathomechanisms of musculoskeletal disorders affecting tendons, ligaments, nerves, muscle, circulation and pain perception are reviewed and conceptual models for the pathogenesis of musculoskeletal disorders affecting the neck and upper limbs are presented. The epidemiological evidence on the work-relatedness of these disorders is discussed. A relationship between the performance of work and the occurrence of neck and upper limb musculoskeletal disorders is evident. Intervention strategies in the workplace for the reduction of both exposure and effect should focus upon factors within the work organisation as well as actively involving the individual worker. The current knowledge is sufficient to enable informed decisions to be made on future research needs and prevention strategies at the societal, organisational and individual level.     

Gender analysis of musculoskeletal disorders and emotional exhaustion: interactive effects from physical and psychosocial work exposures and engagement in domestic work

The objective of this study was to assess the relationships between physical and psychosocial work exposures, engagement in domestic work and work-home imbalance in relation to symptoms of musculoskeletal disorders and emotional exhaustion in white- and blue-collar men and women. Three thousand employees from 21 companies were asked to answer a questionnaire on family structure, household and child care tasks, work exposure, work-home imbalance and symptoms of neck/shoulder disorders, low back disorders and emotional exhaustion. Women reported more musculoskeletal disorders and engagement in domestic work. Adverse at-work exposures were highest in blue-collar women. High engagement in domestic work was not separately associated with symptoms but paid work exposure factors were associated. High engagement in domestic work interacted with adverse work exposure and increased risk estimates for low back disorders and emotional exhaustion. Reported work-home imbalance was associated with neck/shoulder disorders in women and with emotional exhaustion in both women and men. PRACTITIONER SUMMARY: The current article adds to earlier research by showing that high engagement in domestic work is not separately associated with increased symptoms, but interacts with psychosocial work exposure variables to produce emotional exhaustion in both women and men and low back disorders in women.     

Relations between shoulder/neck disorders and EMG zero crossing shifts in female assembly workers using the test contraction method

Pain and discomfort in the shoulder/neck region is a serious problem amongst workers in many categories of assembly work. It has been suggested that these disorders are related to local muscular fatigue. In this study 14 female assembly workers were studied. Several of these women had occupational shoulder/neck disorders of various degrees. The method (FTC), applied during work, involved short test contractions every ten minutes during which EMG from m. trapezius and m. infraspinatus bilaterally was recorded. The EMG was analysed using the zero crossing technique. The subjects filled in a standard questionnaire concerning their muscular shoulder/neck disorders. It is shown that subjects reporting disorders have more pronounced EMG alterations than those without disorders.     

Neck/shoulder and low-back disorders in the forestry industry: relationship to work tasks and perceived psychosocial job stress

In a national cross-sectional study, the prevalence of neck/shoulder and low-back disorders and their relationship to work tasks and perceived psychosocial job stress was studied among forestry employees. The data were collected by occupational health service staff using Karasek's demand/control questionnaire for the psychosocial measures and the Standardized Nordic questionnaire for the analysis of musculoskeletal disorders. Based on data about past and present work tasks, the study population was classified into three groups: 645 manual workers, 66 machine operators and 124 administrative workers. Low-back disorders were more common among the manual workers than among the administrative workers \[odds ratio (OR) = 1.98]. For the machine operators and manual workers, an increasing level of psychological demands was significantly associated with an increased prevalence of low-back disorders. The prevalence of neck/ shoulder disorders was significantly higher among the machine operators (OR = 3.37) and manual workers (OR = 2.34) than among the administrative workers. An increasing level of psychological demands combined with a decreasing level of intellectual discretion was associated with an increased prevalence of neck/shoulder disorders. Authority over decisions was not associated with musculoskeletal disorders. In conclusion, musculoskeletal disorders were associated with both physical and psychosocial work factors. The modest strength of the associations between each individual independent variable and the outcome measure shows, however, that a substantial reduction in the prevalence of musculoskeletal disorders may be difficult to achieve. Nevertheless, the study clearly suggests that in the forestry industry attention should be paid to psychosocial work factors in future organizational changes and preventive programmes.     

Hand and arm injuries associated with repetitive manual work in industry: a review of disorders, risk factors and preventive measures.

Musculoskeletal disorders are the most common self-reported, work-related illness in the UK, with upper limb disorders ranking second only to back complaints. The rapid increase in disablement cases, the reduced productivity resulting from the disorders, and, perhaps, the threat of litigation which is on the increase, has led to an increased awareness of the problems and an increasing desire to reduce the incidence of such disorders. This paper reviews the problem of upper limb disorders and focuses on those disorders that could be associated with repetitive manual work in industry. The disorders are described and categorized, and potential occupational risk factors are discussed and related to the injuries. In addition, a number of preventive measures, in the form of ergonomics design changes and changes in workplace practice are reviewed. There are frequent calls for well-designed epidemiological studies, so that meaningful dose-response relationships can be drawn up. A significant part of good study design is associated with measurement and analysis of the user-tool interface and the working environment. With this in mind, a variety of measurement techniques are described. Furthermore, this paper highlights the need for study designs to be founded on a better understanding of the potential damage mechanisms, and points the way towards which areas should be investigated.     

Occupational disorders affecting agricultural workers in tropical developing countries: results of a literature review

This paper presents the results of a literature review undertaken to determine the nature and extent of occupational health problems in tropical agriculture and to identify opportunities for ergonomics intervention. Occupational disorders were categorized as follows: disorders associated with the use of pesticides; disorders associated with biomechanical and postural demands; and disorders associated with harmful materials other than pesticides. It was concluded that the high rate of pesticide poisoning in tropical agriculture is partly a consequence of the inappropriate transfer of technology from industrialized to developing countries. Ergonomics intervention has the potential to reduce the incidence of occupational pesticide poisoning in developing countries. Biomechanical disorders are commonly presumed to be prevalent in tropical agriculture, but the evidence to confirm this is lacking. Again, ergonomics intervention has the potential to minimize such disorders, but the cultural significance associated with traditional tools and practices must be considered in such a development programme. Disorders associated with contact with harmful materials have been described as occupational diseases. Pesticides aside, these have received little attention, partly because it is difficult to distinguish between occupational and non-occupational incidences of such diseases. Opportunities to reduce the occurrence of these occupational diseases could be limited.     

Mobile phones as medical devices in mental disorder treatment: an overview

Mental disorders can have a significant, negative impact on sufferers’ lives, as well as on their friends and family, healthcare systems and other parts of society. Approximately 25 % of all people in Europe and the USA experience a mental disorder at least once in their lifetime. Currently, monitoring mental disorders relies on subjective clinical self-reporting rating scales, which were developed more than 50 years ago. In this paper, we discuss how mobile phones can support the treatment of mental disorders by (1) implementing human–computer interfaces to support therapy and (2) collecting relevant data from patients’ daily lives to monitor the current state and development of their mental disorders. Concerning the first point, we review various systems that utilize mobile phones for the treatment of mental disorders. We also evaluate how their core design features and dimensions can be applied in other, similar systems. Concerning the second point, we highlight the feasibility of using mobile phones to collect comprehensive data including voice data, motion and location information. Data mining methods are also reviewed and discussed. Based on the presented studies, we summarize advantages and drawbacks of the most promising mobile phone technologies for detecting mood disorders like depression or bipolar disorder. Finally, we discuss practical implementation details, legal issues and business models for the introduction of mobile phones as medical devices.     

An ergonomic study of work methods and physical disorders among professional butchers

Butchers considered that the back and the upper extremities were subjected to high loads from their work. Of the 92% with reported physical disorders, 80% had pains or complaints from more than one body area. Most frequent were disorders of the back and shoulders. 50% of the butchers had been on sick leave due to their disorders. By ergonomic analysis of the work, several work tasks which caused high loads on those body parts in which disorders had occurred were identified. The high loads were found to have the following main causes, which occurred together in many work situations: (1) Exertion of high forces when cutting the meat. (2) Frequent and heavy manual materials handling. (3) Inappropriate working postures. It appeared from the study that the workload on the butchers was unnecessarily high and that it could be the main reason for the high frequency of disorders amongst them. The strain on them was to a large extent caused by bad working postures, which could be improved by introducing improved equipment. The equipment should be such that the working-height may be adjusted both to the individual and for the task performed.     

Evaluating Multimembership Classifiers: A Methodology and Application to the MEDAS Diagnostic System

Performance evaluation measures for multimembership classifiers are presented and applied in a retrospective study on the diagnostic performance of the MEDAS (Medical Emergency Decision Assistance System) system. Admission and discharge diagnoses for 122 patients with one or more of 26 distinct disorders in five major disorder categories were gathered. The average number of disorders per patient was 2 with 36 (29.5 percent) patients having 3 or more disorders simultaneously. The features (symptoms, signs, and laboratory data) available at admission were entered into a multimembership Bayesian pattern recognition algorithm which permits for diagnosis of multiple disorders. When the top five computer-ranked diagnoses were considered, all of the correct diagnoses for 86.1 percent of the patients were displayed by the fifth position. In 71.6 percent of these cases, no false diagnosis preceded any correct diagnosis. In ten cases a discharge diagnosis which was suggested by the available findings was omitted by the admitting physician. In six of these ten cases, the overlooked diagnoses appeared at the computer ranked list above all false diagnoses. Considering the urgency of diagnosis in the Emergency Department, the high uncertainty involved due to the limited availability of data, and the high frequency with which multiple disorders coexist, this limited study encourages our confidence in the MEDAS knowledge base and algorithm as a useful diagnostic support tool.     

Implementation of automated diagnostic systems: ophthalmic arterial disorders detection case

This article intends to give an integrated view of the automated diagnostic systems combined with spectral analysis techniques in the detection of arterial disorders. The article includes illustrative and detailed information about implementation of automated diagnostic systems and feature extraction/selection from signals recorded from ophthalmic arteries. The major objective of the article is to be a guide for readers who want to develop an automated diagnostic systems for detection of arterial disorders. Towards achieving this objective, this article presents the techniques which should be considered in developing automated diagnostic systems. The author suggests that the content of the article will assist people in gaining a better understanding of the techniques in the detection of arterial disorders.     

Quantitative proteomics for investigating psychiatric disorders

The underlying pathophysiology of psychiatric disorders remains elusive. The use of quantitative proteomics to investigate disease-specific protein signatures holds great promise to improve the understanding of psychiatric disorders and identify relevant biomarkers. In this review, we discuss quantitative proteomic approaches for elucidating molecular mechanisms of psychiatric disorders, i.e. anxiety, schizophrenia, bipolar disorder and depression, by studying specimens from animal models and patients. We present gel-based, label-free and stable isotope-labeling methodologies and evaluate their strengths and limitations in the context of psychiatric research, with a focus on (15)N metabolic labeling of live animals due to its increased accuracy and potential for future applications. We also review biomarker candidate validation methods and present quantitative proteomic studies from the literature that aim to disentangle the molecular pathobiology of psychiatric disorders and identify candidate biomarkers. Finally, we explore the applicability of implementing proteomic methods as a routine diagnostic tool in the clinical laboratory.     

Towards co-design with users who have autism spectrum disorders

People with cognitive disorders, such as autism or Asperger’s syndrome, face many barriers when being involved in the co-design of information and communications technologies (ICT). Cognitive disorders may require that co-design techniques be modified to fit with individual abilities. Up until recently, with technology design, purpose and use being in the hands of ‘experts’ there was little opportunity for customisation. However, ICT bring together various threads that make open many new possibilities. Not only are technologies cheaper, more powerful and more available than ever, but now parents, support agencies and people with autism spectrum disorders expect information technologies to be part of their worlds, and they have the capacity to participate in co-design for customisation. However, co-design techniques have not evolved to the extent that they capture this potential democratisation of the ICT. This paper reports on an investigation of the potential to develop a set of guidelines for co-design techniques to enable people with autism spectrum disorders to participate in ICT design.     

Treating psychological and phsyical disorders with VR

We present some applications that therapists have used with patients. Treating psychological disorders is one aspect of a larger application area of VR that we refer to as clinical virtual reality-the direct use of VR as a tool in treating or assessing psychological and physical disorders. Examples of clinical applications that use VR include treatment of phobias, post-traumatic stress disorder in Vietnam War veterans, eating disorders, pain distraction; and physical (stroke and orthopedic) rehabilitation. This article offers some general ideas on how clinical VR applications fundamentally differ from many other VR applications and presents three detailed examples of current clinical VR applications that have moved from the demonstration phase to actual use with patients in a clinical setting     

A model for diagnosing and explaining multiple disorders

The ability to diagnose multiple interacting disorders and explain them in a coherent causal framework has only partially been achieved in medical expert systems. This paper proposes a causal model for diagnosing and explaining multiple disorders whose key elements are: physician-directed hypotheses generation, object-oriented knowledge representation, and novel explanation heuristics. The heuristics modify and link the explanations to make the physician aware of diagnostic complexities. A computer program incorporating the model currently is in use for diagnosing peripheral nerve and muscle disorders. The program successfully diagnoses and explains interactions between diseases in terms of underlying pathophysiologic concepts. The model offers a new architecture for medical domains where reasoning from first principles is difficult but explanation of disease interactions is crucial for the system's operation.     

Personal and psychosocial variables in workers with a previous history of LBP: 16-month follow-up

A 16-month longitudinal study was made of workers who perform physically demanding jobs. In a previous study some of these workers were found to have a history of low back disorders sufficient to miss work, and others not. All were asymptomatic at that time. To further quantify the association between various personal and psychosocial parameters that linger due to a history of low back disorders and how they may change after another 16 months of work. Originally, 72 workers were recruited from heavy industry; 26 of whom had a history of disabling low back disorders sufficient to miss work. In the follow-up study, 46 responded all of whom remained at work injury free, 13 belonged to the ‘history of back disorders’ category. While the earlier study suggested that having a history of low back disorders is associated with a larger waist girth, a greater chronicity potential as predicted from psychosocial questionnaires, perturbed flexion to extension strength and endurance ratios, and widespread motor control deficits across a variety of tasks some of which resulted in high back loads, the follow-up showed no difference in reported physical symptoms, or perceived pain over the 16 months. Both groups changed their responses from the original data collection to the 16-month follow-up with the net result of psychosocial distinguishing traits, in those with a history, diminishing. It was concluded that time and work appear to be healing.     

Upper extremity musculoskeletal disorders at a pulp and paper mill

A small cross-sectional study of upper extremity disorders was conducted in two departments of a pulp and paper mill. The objective of the study was to determine the prevalence of upper extremity disorders and identify any associated work place risk factors in long cycle jobs with multiple tasks of varying duration. Physical exams and health status interviews were conducted on 23 employees (77%) in the paper machine department and on 17 employees (59%) of the power and recovery department. All participants completed questionnaires on physical and psychosocial job characteristics. There was a statistically significant difference in hand and wrist disorders between the two departments at the p < 0.05 level (34.8% in the power and recovery department, and 5.9% in the paper machine area). Multiple logistic regression models showed a significant relationship between the use of a steel lance and shoulder disorders. Elbow arthritis was also associated with lance usage. There was evidence that the job analysis was not able to fully describe the risk factors present in the paper machine department. Biomechanical exposures existing prior to the time of the study may not have been adequately characterized. An important aspect of this study is that the jobs studied were not typical repetitive jobs that are commonly studied.     

Mein Nick bin ich! Nicknames in a German Forum on Eating Disorders

This article demonstrates how nicknames that are used by participants in a German forum on eating disorders can be read as identity displays and how they may be related to eating disorders. A qualitative analysis of 83 nicknames of the Hungrig-Online forum reveals that denotational and stereotypical features, along with well-known referents of the names, interdependently characterize participants. Persona attributes such as smallness, weightlessness, childishness, negative self-evaluation, and depression, but also (arguably) self-confidence, are shown to be apparent in the nicknames; many of these attributes can be linked to multifaceted femininity. These findings are then related to general characteristics of eating disorders. In concluding, the far-reaching rules for registration of nicknames in the forum are taken into account and questioned, for it may be that in sensitive online groups, nicknames play an especially important role in identity construction.     

Previous history of LBP with work loss is related to lingering deficits in biomechanical,physiological, personal,psychosocial and motor control characteristics

A cross-sectional retrospective study was made of currently asymptomatic workers who perform physically demanding jobs. To further quantify the association between various biomechanical, physiological, personal psychosocial and motor control parameters that linger due to a history of low back disorders. Seventy-two workers were recruited from heavy industry, 26 of whom had a history of disabling low back disorders (LBDs) sufficient to miss work while the others did not. The strength of the study lies in the many detailed variables measured. Having a history of low back disorders was found to be associated with a larger waist girth, a greater potential for low back pain chronicity as predicted from psychosocial questionnaires, perturbed flexion to extension strength and endurance ratios, and widespread motor control deficits across a variety of tasks, some of which resulted in high back loads. In those workers who had missed work due to back disorders, the length of time since their last disabling episode was 261 weeks on average, suggesting that multiple deficits may remain for a period of time. Having a history of LBD is associated with changes in attitudes, in body composition, and in the way people move, load their backs and respond to a variety of motor and stability challenges.     

无人水下航行器势场航路规划方法研究

对运动障碍威胁环境下无人水下航行器(UUV)航路规划问题进行了研究;首先分别对规划过程中固定障碍、运动障碍建立了排斥势场,对目标点建立了吸引势场,将航路规划问题转变为寻找最优势场点问题;然后提出一种改进的粒子群算法(NPSO),在UUV航路规划过程中,寻找距离当前路径点固定步长范围内的最优势场点,将其作为下一路径点,最终实现UUV在运动障碍威胁环境中的航路规划;最后对所提方法进行了仿真验证,UUV可以有效躲避固定障碍与运动障碍威胁,寻找到较优航路,取得了较好的仿真效果。     

Impact of physical exposure on neck and upper limb disorders in female workers

Physical workload [muscular load of the trapezius and infraspinatus muscles using electromyography (EMG), wrist positions and movements by electrogoniometers] and neck and upper limb disorders (from, for example, a physical examination) were studied in women with repetitive industrial work (n = 95) and referents (n = 74). The repetitive work displayed higher ratings for wrist movements, but not for EMG. The prevalences of neck, shoulder and wrist/hand disorders were elevated for women with repetitive work [age-adjusted prevalence odds ratios (PORs) 2.0-7.5]. For the left hand, high frequency of wrist movements (mean power frequency 0.53 Hz) was associated with a high prevalence of disorders (56%), as compared to low (0.28 Hz and 26%; POR 3.5). We found no consistent and significant effect of muscular load, on either neck or shoulder disorders. However, selection and other bias may have diminished our possibility to observe such effects. Psychosocial work environment factors were not confounding the results. Measurements of wrist movements may be used for identification of high-risk work tasks.