A Framework for the Classification and Diagnosis of Work-Related Upper Extremity Conditions: Systematic Review Mark G. Boocock, PhD,* Jill M.K. Collier, MHSc, † Peter J. McNair, PhD, ‡ Marian Simmonds, MHSc, † Peter J. Larmer, MPH, § and Bridget Armstrong, MHSc † Objective: A frequently cited problem in epidemiological research is the inadequate operational definition of umbrella terms such as Musculoskeletal Disorders (MSD). Specific conditions at- tached to these labels and their corresponding signs and symptoms are also poorly defined. The purpose of this study was to identify internationally applied terminology and definitions appro- priate to work-related upper extremity (UE) conditions. Methods: An extensive literature search of 15 electronic databases supplemented by personal commu- nications with representatives from national and international health and safety organizations was un- dertaken to identify recognized terminology and definitions appropriate to work-related UE conditions. Results: Information specific to the umbrella terms and their corresponding conditions was ob- tained from 15 countries. The findings revealed a lack of international consensus over appropriate terminology to encapsulate the wide range of conditions falling within the umbrella terms used by these countries. UE conditions could be classified into 3 broad categories: (1) 14 “specific condi- tions” with evidence-based diagnostic criteria; (2) 34 “other specific conditions” with no clearly defined diagnosis; and (3) “nonspecific conditions” requiring a clear pattern of signs and symp- toms to be present for a diagnosis to be made. A dynamic model for classifying work-related UE conditions is proposed which places greater emphasis on specific diagnosis. Conclusions: A systematic approach to the classification and diagnosis of work-related UE conditions is attractive, as it is likely to lead to more precise estimates of the prevalence and cost of UE conditions, as well as improved quality of information on the efficacy of medical and workplace interventions. © 2009 Elsevier Inc. All rights reserved. Semin Arthritis Rheum 38:296-311 Keywords: musculoskeletal disorders, upper extremity conditions, terminology, definition, diagnosis M usculoskeletal disorders (MSD), repetitive strain injury (RSI), occupational overuse syndrome (OOS), and cumulative trauma disorders (CTD) are just some of the umbrella terms that have been used to describe a heterogeneous group of work-related and non- work-related symptoms and disorders (1). Throughout the scientific community, MSD appears to have become the pre- ferred nomenclature as, unlike other terms, it precludes as- sumptions about possible causative factors. However, a fre- quently cited problem within epidemiological research is the lack of adequate operational definitions for MSD, leading to uncertainty over the inclusion of conditions within this um- brella term. Much confusion also surrounds the accurate classification and diagnosis of conditions appropriate to such a label. These difficulties have often led to problems in un- derstanding both the causative factors of MSD and the most effective strategies for their prevention. For the purpose of this review, the term work-related upper extremity (UE) condition will be used. The valid classification or accurate identification of work-related UE conditions is considered by some as a cornerstone of research into understanding the true etiol- ogy of specific occupational disorders (2). Several authors *Senior Lecturer, Health and Rehabilitation Research Centre, Auckland University of Technology, New Zealand. †Senior Research Officer, Health and Rehabilitation Research Centre, Auckland University of Technology, New Zealand. ‡Director of the Health and Rehabilitation Research Centre, Auckland University of Technology, New Zealand. §Head of Physiotherapy, School of Health and Environmental Studies, Auckland University of Technology, New Zealand. Address reprint requests to Mark Boocock, PhD, Health and Rehabilitation Re- search Centre, Auckland University of Technology, Private Bag 92006, Auckland 1142, New Zealand. E-mail: mark.boocock@aut.ac.nz. QUALITY OF LIFE 296 0049-0172/09/$-see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.semarthrit.2007.10.006