Variance and Dissent

Classifying the forest or the trees?

The importance of our upper limbs

Dr. Hadler points out the importance we ascribe to our upper extremities in our everyday language. What is most interesting is that these phrases often refer to our ability to work. To those phrases Dr. Hadler put forward we add “many hands make light work,” “use a little elbow grease,” “roll up your sleeves and get to work,” “put your shoulder to the wheel,” “our future is in our hands,” and even “carry the weight of the world on your shoulders.” In our view, these phrases reflect people's

Classification

A good classification system, as Dr. Hadler would concur, is one in which individuals are separated into meaningful groups. The assignment must be reliable, and the groups valid [6]. Validity depends on the intended application [6], [7]. Dr. Hadler questions the validity of these systems because they fail to “prove” causality, and therefore, legitimacy. We have chosen to move outside the protracted debate over causality and legitimacy to describe how people with MSK pain present in a workplace

Classification based on etiology

In our review [1] we describe and compare classification systems used for upper limb disorders regardless of their purpose. The developers of these systems often used what Syme calls “clinical classification” schemes, which imply an underlying pathophysiology of the disorders. Although these schemes may be useful in clinical situations (prognosis, treatment), Syme suggests they may not be useful in studies of etiology [7]. Dr. Hadler also suggests that the limitations of the current upper limb

Classification based on social constructs

We whole-heartedly agree with Dr. Hadler that there are many factors that are associated with the occurrence of MSK pain in workers and its impact on a given person. Indeed, in an earlier phase of this project we published work suggesting that psychosocial issues (such as workplace stresses like deadlines) were significantly associated with MSK pain along with physical and individual factors [13], [14].

The classification system based on social constructs that Dr. Hadler proposes may not help to

The forest AND the trees

The melodious opportunity for consistent classification is possible. The need for a clear, consistent, and widely used classification system is well known [16], [17], [18], [26], [27], [28]. Recent work in Europe is moving toward a consensus in the use of a physical examination schedule for the classification of these disorders including “regional musculoskeletal disorders” [17], [18], [29], [30]. Our review adds to this growing body of work by making explicit the lack of consistency in the