Did you know our bones are constantly remodeling and rebuilding? That's right. With various factors including nutrition and hormones, one of the most influential to bone health is stress. bone remodels in response to the forces which act upon it (Wolfs Law).
Often stress is seen as a bad thing but this is an example where stress is "food". Gravity alone creates a level of force on the body that helps with bone health. This is observed more clearly in astronauts who, without the impact of gravitational force, have exhibited 1-2% bone loss per MONTH compared to 1-1.5% bone loss in elderly or 2-3% in post menopausal women per YEAR.
This is also why weight bearing, resistant exercises are so important for bone health as the balance of tensive and compression forces help maintain and promote bone health.
What happens when this is out of balance though? Obviously if the bone "breakdown" occurs faster than the one "buildup" we will see a decrease in density. The opposite can occur also thought. If the stresses are abnormally distributed or if there is repetitive stress on a particular joint, the body senses this and starts depositing more bone to add stability to the area. This can eventually lead to bone spurs (as seen in the heel particularly with chronic plantar fasciitis) or joint degeneration in the spine or other jouints.
Maintaining and optimizing body balance through alignment, posture and appropriate movement can be important considerations to promote bone health and to prevent or minimize pain and immobility that can accompany degenerative change.