Management of work-relevant upper limb disorders: a review

Background Upper limb disorders (ULDs) are clinically challenging and responsible for considerable work loss. There is a need to determine effective approaches for their management. Aim To determine evidence-based management strategies for work-relevant ULDs and explore whether a biopsychosocial approach is appropriate. Methods Literature review using a best evidence synthesis. Data from articles identified through systematic searching of electronic databases and citation tracking were extracted into evidence tables. The information was synthesized into high-level evidence statements, which were ordered into themes covering classification/diagnosis, epidemiology, associations/risks and management/treatment, focusing on return to work or work retention and taking account of distinctions between non-specific complaints and specific diagnoses. Results Neither biomedical treatment nor ergonomic workplace interventions alone offer an optimal solution; rather, multimodal interventions show considerable promise, particularly for occupational outcomes. Early return to work, or work retention, is an important goal for most cases and may be facilitated, where necessary, by transitional work arrangements. The emergent evidence indicates that successful management strategies require all the players to be onside and acting in a coordinated fashion; this requires engaging employers and workers to participate. Conclusions The biopsychosocial model applies: biological considerations should not be ignored, but psychosocial factors are more influential for occupational outcomes. Implementation of interventions that address the full range of psychosocial issues will require a cultural shift in the way the relationship between upper limb complaints and work is conceived and handled. Dissemination of evidence-based messages can contribute to the needed cultural shift

Production Systems for Manual Repetitive Jobs. Effects on Autonomy and Variety of Work and Prevalence of Musculoskeletal Disorders in Upper Limbs

The aim of this thesis is to improve workers\u27 conditions and it deals particularly with companies in the engineering industry. In many of these companies, production systems are designed to have manual repetitive jobs. Many such jobs are characterized by static work positions and repetitive motions, which are considered to be risk factors for musculoskeletal disorders in the upper limbs. There is a lack of knowledge of how to prevent the development of such disorders, but a variety of tasks and muscular activities are viewed as a means for preventing musculoskeletal disorders in upper limbs. Autonomy can be seen as a prerequisite for variety. In this thesis, the overall objective was to gain better knowledge of how to design production systems for manual repetitive jobs. A first purpose was to analyze how manual repetitive jobs in the engineering industry were in fact designed. A second purpose was to study interrelationships between work roles, work behavior, work-related stress and the prevalence of musculoskeletal disorders in the upper limbs, as well as how individual worker characteristics influence these relationships. The work has thus been explorative. Four case studies were made in two companies where the methodology mainly involved interviews, medical examinations, observations of work, use of questionnaires and video recordings. Three reference case studies were also carried out. All case studies focused on work groups. The thesis work emerged in a number of stages. Initially, a method for detailed analyses of hand and arm movements was developed on the basis of technical and medical methods. The so called Hand-Arm-Movement-Analysis (HAMA) method was used to analyze assembly tasks and illustrate work methods and work positions in the first case study. Using theories and empirical data, three theoretical models were successively developed during the thesis work. The models were used as a frame of reference in the analysis of the production systems studied. One model treats relationships between work role, work behavior, work-related stress and influence of individual worker characteristics, while the two other models treat the design of and factors influencing the design of production systems. Briefly, a production system is described as consisting of a social and a technical system. The results of the case studies show that manual repetitive jobs were designed differently, with different task contents, both within and between the companies studied. This especially concerned the extent to which workers were given autonomy and variety in their work, which differed between the work groups as well as the different work roles. The results show that workers differed greatly as regards work behavior (i.e. work method, work pace, work position and work-rest patterns) even when carrying out the same task. The prevalence of musculoskeletal disorders in the upper limbs was highest in the company in which workers were given higher autonomy as regards the technical system, more limited autonomy as regards the social system, high object variety and limited motor variety. The conclusion arrived at in this thesis is that there are many aspects of autonomy and variety that should be considered when production systems are designed, as autonomy and variety were found not to be one-dimensional concepts. More research is needed to analyze the importance of different aspects of autonomy and variety for the risk of musculoskeletal disorders in the upper limbs.More research is also needed to validate the theoretical models presented

No Standard, New York

A creative incubator for global nomads. The Standard Hotel, reimagined and transformed intoa vibrant, dynamic hub for global nomads who value transience over permanence. Repurposed to inspirethe cross-pollination of ideas, it serves as a temporary home for those in a perpetual state of transition. Designed to generate serendipitous interactions, it exists to connect people of different social classes and histories

Production Systems for Manual Repetitive Jobs. Effects on Autonomy and Variety of Work and Prevalence of Musculoskeletal Disorders in Upper Limbs

The aim of this thesis is to improve workers\u27 conditions and it deals particularly with companies in the engineering industry. In many of these companies, production systems are designed to have manual repetitive jobs. Many such jobs are characterized by static work positions and repetitive motions, which are considered to be risk factors for musculoskeletal disorders in the upper limbs. There is a lack of knowledge of how to prevent the development of such disorders, but a variety of tasks and muscular activities are viewed as a means for preventing musculoskeletal disorders in upper limbs. Autonomy can be seen as a prerequisite for variety. In this thesis, the overall objective was to gain better knowledge of how to design production systems for manual repetitive jobs. A first purpose was to analyze how manual repetitive jobs in the engineering industry were in fact designed. A second purpose was to study interrelationships between work roles, work behavior, work-related stress and the prevalence of musculoskeletal disorders in the upper limbs, as well as how individual worker characteristics influence these relationships. The work has thus been explorative. Four case studies were made in two companies where the methodology mainly involved interviews, medical examinations, observations of work, use of questionnaires and video recordings. Three reference case studies were also carried out. All case studies focused on work groups. The thesis work emerged in a number of stages. Initially, a method for detailed analyses of hand and arm movements was developed on the basis of technical and medical methods. The so called Hand-Arm-Movement-Analysis (HAMA) method was used to analyze assembly tasks and illustrate work methods and work positions in the first case study. Using theories and empirical data, three theoretical models were successively developed during the thesis work. The models were used as a frame of reference in the analysis of the production systems studied. One model treats relationships between work role, work behavior, work-related stress and influence of individual worker characteristics, while the two other models treat the design of and factors influencing the design of production systems. Briefly, a production system is described as consisting of a social and a technical system. The results of the case studies show that manual repetitive jobs were designed differently, with different task contents, both within and between the companies studied. This especially concerned the extent to which workers were given autonomy and variety in their work, which differed between the work groups as well as the different work roles. The results show that workers differed greatly as regards work behavior (i.e. work method, work pace, work position and work-rest patterns) even when carrying out the same task. The prevalence of musculoskeletal disorders in the upper limbs was highest in the company in which workers were given higher autonomy as regards the technical system, more limited autonomy as regards the social system, high object variety and limited motor variety. The conclusion arrived at in this thesis is that there are many aspects of autonomy and variety that should be considered when production systems are designed, as autonomy and variety were found not to be one-dimensional concepts. More research is needed to analyze the importance of different aspects of autonomy and variety for the risk of musculoskeletal disorders in the upper limbs.More research is also needed to validate the theoretical models presented

An Exploration of Models for Software Faults and Errors: a Journey through Field Data and Injection Experiments

Society is becoming quite dependent on computer-based systems. Today, computers are embedded in wristwatches, vending machines, factory equipment, automobiles and aircraft. A failure in a computer-based system that controls critical applications may lead to significant economic losses or even the loss of human lives. The causes of failures in computer-based systems are manifold: physical faults, maintenance errors, design and implementations mistakes resulting in hardware or software defects, and user or operator mistakes. These causes - faults - are all undesired circumstances that hinder the system from delivering the expected service. There are two complementary ways to ensure that a system delivers the expected service: fault prevention, i.e. avoid the introduction of faults; and fault tolerance, i.e. ensure that the system delivers its service despite the presence of faults. This thesis addresses fault tolerance. A fault-tolerant system should tolerate both hardware and software faults, as both categories can have a great impact on it. Furthermore, it is essential that confidence in a fault-tolerant system's ability is reached if it shall be deployed for critical applications.<p /> One attractive approach to reach confidence in a fault-tolerant system's capability is fault injection. Fault injection can be used for studying the effects of hardware and software faults. However, in both the academic community and industry, most fault injection studies have aimed at the effects of physical hardware faults. Only a few studies have been concerned with software faults, for the reason that knowledge of software faults experienced by systems in the field is limited. As a result, it is difficult to define realistic fault sets to inject. This is crucial if a fault injection experiment is intended to quantify a system's fault tolerance. Consequently, more research is needed in the fault injection area - especially studies targeting software faults and errors induced by them.<p /> This thesis contributes towards fulfilling this need by investigating models of software faults and models of errors induced by software faults. Techniques for emulating representative software faults were also implemented and evaluated. Specifically, an investigation of software faults experienced by a large IBM operating system product was carried out. In addition, general procedures that allow injection experiments to be based on field data were devised and put into practice to emulate software faults in an embedded real-time system.<p /> The novelty of the work of this thesis is the usage of general procedures to construct models of software faults and of software induced errors - on the basis of field data - in injection experiments. No such research has been carried out previously. The combined usage of the procedures and the injection techniques is the major contribution of this thesis. The use of these procedures and techniques is mainly in validation efforts aimed at predicting a fault-tolerant system,s ability to detect and process the effects of software faults