Henry Ford Hospital Medical Journal


Using Frost's method for undecalcified bone sections, long bones of the lower extremities of ten rhesus monkeys were examined following two months' immobilization and compared with thirteen controls. A decrease in appositional rate and in the surface extent of the ossification process were noted in the immobilized animals. No typical change in resorption was noted. The immobilized animals showed a decreased cortical-total area ratio. These findings suggest that a decrease in activity affects bone by depressing functions mediated by the osteoblast without necessarily evoking an Increased remodelling response.