Disuse atrophy of the quadriceps muscle and knee joint stiffness at the end of a 3-month period of immobilisation in patients with a fracture of the shaft of the femur is a common problem. A new approach to it was recently researched by applying a quadriceps endurance programme to a sample of this target population. Endurance capacity of matched experimental and control groups, consisting of 11 patients each, was tested at the end of the immobilisation period. Only the experimental group received the treatment intervention. Quadriceps endurance capacity in the experimental group at the end of the test period was at a 97% level compared with normal, uninjured subjects, while the control group's performance level was 57%. The difference is highly significant (P less than 0.0001). The problem of disuse atrophy had been successfully overcome in the experimental group. The unaffected leg of 10 patients from the same target population was also tested at the end of the immobilisation period. The mean value achieved was similar to the norm, i.e. there was no significant difference when compared with normal quadriceps endurance capacity.