Loss of bone density and muscle mass (muscle atrophy due to lack of use) are the primary causes for the elderly's diminished/shrinking frame. Fractures also can cause stooping and other posture problems that diminish the bodyframe in terms of height. People typically lose about half an inch each decade--starting at around age 40 (!!), with a faster rate of shrinkage after age 70. Senior citizens may shrink as much as three inches! Yikes. So enjoy it while you can; keep your bones and muscles strong through vitamin D, calcium, a balanced diet, and especially regular exercise.
