Stress response of the tibial cortex: a longitudinal radiographic study

The influence of physical exercise on bone tissue was studied in a sample of 30 conscripts, who served in the coast commando battalion . A repeated roentgen examination of the lower legs was performed after 10, 20 and 40 weeks' service. In the anterior cortex of mid-diaphysis of the tibia a structural change in bone could be regularly observed. In the first examination (after 10 weeks) the cortical bone was longitudinally striated. In the next control (after 20 weeks) the finding was less pronounced. After 40 weeks the bone structure was quite homogenous and solid. The cortical thickness did not change significantly during the 40 weeks follow-up. Most of the diagnosed stress lesions (73%) in bone were developed during the first 10 weeks.