Summary As normal life becomes easier from one generation to another, work and daily activities can be managed with fewer demands on the mobility and strength of the musculoskeletal system. But if the system is not regularly taxed by other means, symptoms from unaccustomed activity become more likely. Acute musculoskeletal pain, for the time being, makes a further reduction in the normal levels of exertion and movement; so increasing susceptibility to further trouble if it is not rapidly relieved. If rest is therapeutically prolonged, then rehabilitation becomes increasingly difficult. Immobilisation, moreover, is now recognised as a potential cause for osteoarthritis. The need for active management of acute musculoskeletal symptoms at the earliest possible stage is therefore clear. The difficulty lies in recognising where the need is greatest. Taking the population as a whole, capacity for work is reduced not only by current but also by previous symptoms. The experience of pain and the fear it engenders seem permanently to reduce the capacity for exertion and it is in such people that we may look for recurrent and chronic musculoskeletal symptoms. If fear of pain and the signs of pain-avoidance or illness-behaviour are ignored, omitted from the diagnosis and remain untreated, musculoskeletal morbidity may positively be encouraged instead of prevented.