FEMUR-BENDING PROPERTIES AS INFLUENCED BY GRAVITY .1. ULTIMATE LOAD AND MOMENT FOR 3-G RATS

  • 1 January 1977
    • journal article
    • research article
    • Vol. 48  (4) , 339-346
Abstract
Fresh experimental bones can withstand greater bending forces and moments after 1.0-2.5 wk of 3 g exposure. This appears more attributable to a 50% greater strength of bone material than to effects upon size or shape and is most measurable for animals of 5-8 wk of age. Experimental bone material grew to its mature level at a younger age rather than there being so marked an effect upon the mature level itself. Albino rats (66) were exposed to 3.1 g by chronic centrifugation and compared to 63 1 g controls. Extrapolation of the simplest mathematical description of the results to weaker, 0 g bones were tested by a total of 60 space-based control and experimental animals. A flight of only 15 animals was necessary for comparison to ground-based control animals. This was consistent with reports of bone demineralization during space-flight. In light of the differences in bone histology extrapolation of these results to humans may be premature and may only be applicable for children rather than adults.