A study of functional ability--in relation to joint impairment and disability--in 79-year-olds was performed on representative subsamples by interview (n = 134) and physical examination of joints (n = 89) as well as interview and functional tests regarding activities of daily living (ADL) (n = 84). Joint complaints of the lower extremities were more frequent than complaints of the upper extremities. Restricted knee motion had the highest correlation to disability of entering public transports. Previous sedentary workers were more disabled in ADL functions than those with a previous strenuous physical work. Correlation was found between low physical activity in the leisure time and impaired ADL functions. Low physical activity in the group with no definable disease was also correlated with greater social assistance. The reasons for commitment to institutional care were usually complex and, generally, not caused by joint impairment. Although disability had increased within the sample since age 70, at age 79 sixty per cent of the probands could still manage household tasks and personal care, and 69% did not require walking aids. The 79-year-olds thus display a high degree of musculoskeletal ability.