The causes of senile round back are spinal osteoporosis, disk narrowing, back muscle atrophy and others. We investigated 50 cases of senile round back (male: 13 cases, female: 37 cases, mean age: 73.0 y. o.). They are classified into 2 groups according to the type of round back, namely, 1) the upper group in which the apex of kyphosis is located in the middle thoracic spine, and 2) the lower group in which the apex is in the thoraco-lumbar junction. The cause of round back of the upper group mainly disk narrowings, and that of the lower group is wedged vertebral bodies. Power of the back muscles in the upper group is stronger than that of the lower group.
