Occupation and upper limb disorders

Sir, The editorial by Coggon et al. [1] calls for further research on the pathogenesis, diagnosis, natural history and treatment of upper limb disorders. Particular emphasis is placed on occupational factors, although the authors are careful to avoid such pejorative terms as ‘work‐related’. While we agree in principle with this plea, we consider that good quality research of the kind they envisage will be very difficult to perform. The main reason for this is the difficulty in finding a large stable workforce with a cooperative management. Furthermore, within this workplace, jobs should be sufficiently varied to provide a spectrum of different physical exposures. It may be possible to use workers from different industries to provide the latter conditions, but investigators would then lose control over workplace organizational determinants. In fact, many industries have already adopted ergonomic modifications into their workplace as a result of efforts by such bodies as the Health and Safety Executive in the UK [2] and the Occupational Safety and Health Administration in the USA [3], despite the absence of randomized controlled trials. However, it is important to note that ergonomic interventions are not simply concerned with physical load but also with factors such as work systems, control and organization. There is a parallel between non‐specific mechanical low back pain and non‐specific upper limb disorder [4], although the demographic characteristics of the populations are different. In the absence of more complete data relating to upper limb disorders, perhaps we should apply the available evidence about low back pain. In low back pain, we know that psychosocial factors and workplace organizational factors are more important in symptom presentation than physical factors, although physical factors play a part [5]. The results of the studies suggested by Coggon et al. may not be available for some time, but many of the answers they require may already be available from the low back pain literature. Correspondence to: W. J. Taylor. We agree that parallels between back pain and non‐specific upper limb pain may be informative. However, analogies may not be exact, and they require empirical confirmation. While some study designs would require co‐operation from employers, in our experience this can be achieved.