The normal spine has a forward curve of about 40-degrees in the mid-upper back area. This curve can increase by 10-degrees or more with just a single fracture in the spine.
As we get older, bone loses strength and density. It becomes thinner and weaker. The force of gravity along with changes in posture can cause the front of the spine to collapse at one or more levels.
Spinal curves of more than 70-degrees are common in older adults with more than one fracture. As the bone collapses, it forms a wedge- or pie shape. The vertebral bones lose height causing a loss of overall body height.