There has been increasing interest recently in the presentation and packaging of drugs for elderly patients and the manufacture of child-proof containers. This had led to the development of specially designed bottles or blister packs now commonly used fur over the counter analgesic preparations. Rheumatoid arthritis and osteoarthrosis are common diseases and many patients suffering from these diseases develop considerable deformities of the hand leading to an inability to perform activities of daily living. In a previous study (Mason et. al.) 200 patients with rheumatoid arthritis were shown to have difficulty in opening child-proof containers. In this study we decided to include patients with osteoarthrosis as well and to test the ability of both rheumatoid and osteoarthritic patients to open blister packs as well as child-proof containers