Effects of experimental bipedalism on the growth of the femur and tibia in normal and hypophysectomized rats.

Male and female Sprague-Dawley rats were used to see if increased, intermittent, compressive forces, produced by experimental bipedalism would have a compensatory effect on hypophysectomy - a situation known to inhibit bone growth. Half of the rats underwent amputation of both front legs at 10 days of age; and at 21 days of age, half of the normal and half of the bipedal rats underwent hypophysectomy. All rats were sacrificed at 55 days of age, and weighed. The femora and tibiae were removed, cleaned, fixed, weighed and measured. The results of this study suggest that increased, intermittent, compressive forces may be instrumental in increasing long bone growth among adolescent females.