In this paper some quality issues of epidemiologic studies on work-related
musculoskeletal diseases are discussed. The advantages and disadvantages of
different types of epidemiologic studies are described, among them the rar
ely applied case-crossover design. Problems in the ascertainment of disease
, as well as the assessment of exposure to physical load, are also brought
up. The importance of understanding the pathomechanisms of the diseases und
er study is stressed.