We have investigated the level of physical activity of 49 women between the ages of 15 and 45 years who sustained a fracture of the neck of the femur at between 60 and 70 years of age, and compared this with the level of activity reported by 49 control subjects without fracture, who were matched for age and social status. We found that the patients had been significantly less physically active than the controls, especially as regards household duties and professional working conditions.